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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 100 (2000), S. 895-898 
    ISSN: 1432-2242
    Schlagwort(e): Key words Diallel analysis ; Regeneration ability ; Cotyledonary culture ; Brassica napus ; Heritablity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Genetic analysis of shoot regeneration from cotyledonary explants of Brassica napus was carried out by 7×7 diallel crosses using cultivars showing a different ability for regeneration. Both additive and dominant effects were significant, with the additive effect being more important than the dominant one. Dominant genes had a positive effect on shoot regeneration. Non-allelic interaction and average maternal effects were not detected, while specific the maternal one was significant. In the 5×5 sub-diallel table, the maternal effect became nonsignificant. The mean degree of dominance was 0.759. Broad- and narrow-sense heritabilities were 0.973 and 0.819, respectively, indicating that shoot regenera- tion ability can be easily transferred into economically important cultivars showing a low or an unresponsive ability.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1432-2242
    Schlagwort(e): Key words. Fertility Restoration (Rf) ; Cytoplasmic male sterility (CMS) ; Raphanus sativus L. ; Brassica napus ; Mitochondria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The genetics of fertility restoration (Rf) of kosena radish CMS has been characterized. The kosena CMS-Rf system is genetically the same as that of the ogura CMS-Rf system. Two dominant genes that act complementary to the restoration of fertility control fertility restoration in kosena CMS. One allele (Rf1) is associated with accumulation of the CMS-associated protein, ORF125. The interaction of Rf1 and another allele (Rf2) was essential for the restoration of fertility in radish, whereas Rf1 alone was sufficient for the complete restoration of fertility in the B. napus kosena CMS cybrid.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Plant cell reports 19 (2000), S. 1177-1183 
    ISSN: 1432-203X
    Schlagwort(e): Keywords Rapid-cycling ; Brassica napus ; Somatic embryogenesis ; Secondary embryogenesis ; Regeneration ; In vitro Howering ; AbbreviationsABA: Abscisic acid ; BAP: 6-Benzyl-aminopurine ; DAP: Days after pollination ; 2-iP: 6-(γ, γ-dimethlyallyl-amino)purine ; Kinetin: 6-Furfurylaminopurine ; MS: Murashige and Skoog ; SE0: Somatic embryo from seed ; SE1: First-generation secondary embryo ; SE2: Second-generation secondary embryo ; Zeatin: 6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  A simple method to induce somatic embryogenesis from seeds of rapid-cycling Brassica napus is described. Seedlings cultured on Murashige and Skoog (MS) basal medium produced somatic embryos directly on hypocotyls and cotyledons after 2 to 3 subcultures onto the same medium. A low pH of the medium (3.5–5) was more conducive to somatic embryogenesis than a higher pH (6 and 7). Embryogenic potential of the seeds was inversely correlated to seed age: about 41–68% of immature seeds between the ages of 14 and 28 days after pollination (DAP) formed somatic embryos compared to 0–11% of the seeds obtained 29–37 DAP. About 54% of the somatic embryos produced secondary embryos after subculturing onto the same medium. The embryogenic potential of the cultures has been maintained on MS basal medium for 2 years (12 generations) without diminution. Up to 75% of the secondary embryos developed into plantlets on MS medium enriched with 10–6  M zeatin, and 40% of these produced flowers when transferred to an optimised flower-induction medium. Viable seeds were produced in self-pollinated in vitro flowers.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-2145
    Schlagwort(e): Key words Freeze-substitution ; Transmission electron microscopy ; Brassica napus ; Tapetum ; Microspore ; Immunogold
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The method of rapid freeze-fixation and substitution was used with Brassica napus floral bud material in order to improve the preservation of microspore and tapetal organelle structure. When observed using transmission electron microscopy, the appearance of the freeze-substituted material differs in a number of ways from the chemically-fixed material previously studied, in particular for the lipid-rich elaioplasts and tapetosomes in the tapetal cells. The tapetosomes have a very electron-dense, opaque appearance when visualized after rapid fixation. In addition, we were able to observe other cytoplasmic details such as pockets in the endoplasmic reticulum and cytoskeletal structures such as microfilaments. Extracellular material was also well-preserved; for example, the fibrous material in the baculae of the developing microspore exine was also visible. Finally, in the freeze-fixed sections specific structures such as elaioplasts could be labelled by antibodies, which indicates that this method preserved protein epitopes that were destroyed by chemical fixation.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-2145
    Schlagwort(e): Key words Gene-specific expression ; skp1-like gene ; GUS staining ; Gametophytic expression ; Brassica napus ; Arabidopsis thaliana
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  We isolated a gene, BnSKP1γ1, expressed in rapeseed (Brassica napus) microspores, which encodes a protein closely related to the Saccharomyces cerevisiae Skp1p protein previously shown to play a role in cell cycle regulation. Twelve SKP1-related genes have already been identified in the Arabidopsis thaliana genome. Using a PCR-based strategy, we isolated three other genes. To date, most data available concerning the function of the SKP1-related genes in plants are indirect. Studies on transgenic A. thaliana plants showthat a 1100-bp BnSKP1γ1 promoter fragment can direct GUS expression in female gametophytes soon after the first haploid mitosis and in male gametophytes from the tetrade stage. No GUS expression can be detected in sporophytic tissues. RT-PCR experiments suggest that this gene is expressed in a similar way in rapeseed. This is the first reported case of a gene exhibiting such an expression pattern in angiosperms.
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  • 6
    ISSN: 1573-1561
    Schlagwort(e): Brassica napus ; Pratylenchus neglectus ; nematode ; 2-phenylethyl glucosinolate ; isothiocyanate ; pest resistance ; disease break ; variability ; genetic analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Root concentrations of 2-phenylethyl glucosinolate in canola, Brassica napus, influence the susceptibility of the crop to the root lesion nematode (Pratylenchus neglectus), as well as the nematicidal effect of root tissues as they degrade in the soil. Plants containing high 2-phenylethyl glucosinolate should therefore reduce soil populations of P. neglectus. A selection program was developed to increase the proportion of total glucosinolates contributed by 2-phenylethyl glucosinolate in the roots of B. napus cv. Dunkeld. Variation within this accession was observed to be stable across the S1 and S2 generations. The segregation observed for 2-phenylethyl glucosinolate percentage suggested that the trait was encoded at a single locus, with the "high" phenotype being dominant. Plants with the high 2-phenylethyl glucosinolate phenotype (〉45% of total glucosinolates) were shown to be significantly more resistant to P. neglectus than otherwise identical "low" phenotypes (〈45% of total).
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 26 (2000), S. 1411-1422 
    ISSN: 1573-1561
    Schlagwort(e): Brassica napus ; defense-related proteins ; environmental effects ; induced defenses ; proteinase inhibitors ; regulation ; resistance ; trypsin inhibitors ; variation ; wounding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract We examined several environmental and developmental influences on trypsin inhibitor (TI) activity in leaves of young Brassica napus seedlings in a series of greenhouse experiments. In seedlings of B. napus cv. Westar, TI activity is constitutively present and exhibits a rise then fall through time in the first true leaves of young plants. TI activity is induced by wounding in the first true leaves, but the degree of induction is relatively insensitive to the degree of wounding over a gradient of 5–15% of leaf area damage. TI activity is enhanced in first true leaves of plants in which the cotyledons have been wounded relative to plants in which the cotyledons have not been wounded. TI activity is also enhanced in the second true leaves on plants in which the first true leaves have been wounded. The degree of systemic induction in second true leaves declines additively with plant age, but local induction in the first true leaves is not affected by age. In B. napus cv. Gido, TI activity is constitutively present but is not locally wound-inducible in first true leaves of young plants exposed to the same wounding gradient as cv. Westar. In unwounded plants at the six-leaf stage, TI activity is higher in second true leaves than in fifth true leaves, indicating that TI activity is developmentally regulated in this cultivar.
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 26 (2000), S. 2387-2399 
    ISSN: 1573-1561
    Schlagwort(e): Rhizopus spp. ; Fusarium spp. ; rhizosphere microorganisms ; Brassicaceae ; Rorippa sylvestris ; Brassica napus ; Brassica juncea ; Lepidium sativum ; myrosinase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract We isolated several strains of Rhizopus and Fusarium spp. as dominant fungi in the rhizospheres of Brassicaceae plants. The Fusarium isolates showed a higher tolerance of the antifungal constituents of "mustard oil," which originates from the glucosinolates that are characteristic secondary metabolites of the Brassicaceae, than other Fusarium isolates from non-Brassicaceae plants. In contrast, the Rhizopus isolates showed a high tolerance regardless of their source. Myrosinase activity was found in Bn-R-1-1 (Rhizopus sp.) isolated from the rhizoplane of Brassica napus and Ls-F-in-4-1 (Fusarium sp.) isolated from a surface-disinfected root of Lepidium sativum (Brassicaceae). Ls-F-in-4-1 was the Fusarium most tolerant of the Brassicaceae antifungal constituents. These results suggest that fungi in the rhizospheres of Brassicaceae plants may be selected because of secondary metabolites exuded from the roots of host plants.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1570-7458
    Schlagwort(e): Ceutorhynchus assimilis ; Trichomalus perfectus ; Brassica napus ; cabbage seed weevil ; parasitoid ; oilseed rape ; spatio-temporal distribution ; SADIE
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The spatio-temporal distribution of Ceutorhynchus assimilis Payk. (Coleoptera: Curculionidae) adults caught in a rectangular grid of flight traps in a crop of winter oilseed rape (Brassica napus L.) was mapped and was analysed using Spatial Analysis by Distance IndicEs (SADIE). Their distribution was compared to that of their larvae and that of their parasitoid Trichomalus perfectus (Walker) (Hymenoptera: Pteromalidae) in pods. The distribution of immigrating C. assimilis adults was consistent with their arrival at the crop boundaries and movement within the crop towards its centre. Adult C. assimilis were aggregated at all times, invasion being on two fronts, leading to the formation of two major clusters within the crop. Large areas of the crop remained relatively unpopulated. During the emigration phase, numbers declined simultaneously in all parts of the crop. The distributions of adult and larval C. assimilis and of larval T. perfectus were spatially associated. The distribution of the parasitoid did not show a density dependent relationship with that of its host. We discuss the movements of insects which underlie their population distributions, the value of integrating spatial information into improved management strategies for C. assimilis and the potential for the spatial targeting of insecticides to reduce the amount applied and to conserve T. perfectus.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; doubled haploids ; high oleic acid rapeseed (HOAR) ; in vitro selection ; microsporeculture ; mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Microspore derived embryos (MDEs) in Brassica napuscontain large amounts of storage lipids which show a genotype specific fatty acid composition (FAC). One cotyledon of regenerating emblyos can be dissected at an early stage during the in vitro culture and used for fatty acid analysis. Thus, in breeding programmes to modify oil quality, only MDEs having the desired FAC need to be regenerated to plantlets and transferred to the greenhouse. In the present study the applicability of this method for the selection of a high oleic acid content and a low linoleic acid content in the seed oil has been tested by crossing a Brassica napus mutant line having a high oleic acid (C18:1) content in the seed oil (75%) with a wild type doubled haploid line with 62% C18:1 in the seed oil. Microspore culture was applied to the F1 plants. In total 59 MDEs were obtained, from which 31 were cultured with and 28 without 15μM abscisic acid for 3 weeksin vitro. One cotyledon was dissected under aspetic conditions and used for fatty acid analysis. The remaining part of the embryos were further regenerated to plantlets and transferred to the greenhouse to obtain seeds after self pollination. Seeds harvested from the doubled haploid lines in the greenhouse were used for fatty acid analysis and also for growing in the field. The abscisic acid treatment of the MDEs generally improved the correlations for linoleic and oleic acid between the MDEs and the seeds harvested in the greenhouse and the field. The correlations ranged from 0.68** to 0.81**.This indicates that selection for high oleic acid can be started already during an early stage of the in vitro culture.
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  • 11
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; germination test ; herbicidetolerance screening ; monitoring ; PAT-ELISA ; PCR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A novel screening test is described for the discrimination of transgenic phosphinothricin tolerant oilseed rape from non transgenic rape seedlings. The method is based on the germination of rape seeds on filter paper soaked with a 0.005% phosphinothricin solution. Under these conditions inhibition of seedling development by the herbicide can be observed after 10 days. The germination test gains an advantage over the routinely used herbicide spraying, because it is rapid, needs little space and allows efficient screening of huge numbers of seeds. The assay has been successfully applied to the screening of different transgenic and non transgenic rapeseed varieties/lines and has been compared to other methods such asBasta® spray test, drop test, ELISA-technique and PCR-amplification of the pat gene. This test allows on one hand large screening programmes to monitor the foreign gene in the environment and on the other quality control of seedlots before market introduction of herbicide tolerant oilseed rape.
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Euphytica 113 (2000), S. 207-210 
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; hybrid seed production ; self-incompatibility ; swedes, rutabaga
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Procedures for producing seed of hybrid swedes using self-incompatibility were examined. Single-cross, double-cross and modified double-cross hybrids were compared in isolation plots using natural pollinators and in polythene tunnels using blow-flies. With good coincidence of flowering and the same flower colour, nearly 100% hybrid seed was produced by natural pollinators with the single-crosses, the double-cross and one of the two modified double-cross hybrids; the other modified double-cross hybrid produced 87%hybrid seed. With poor coincidence of flowering and different flower colours the proportion of hybrids dropped to 61%. Using different flower colours and blow-flies as pollinators in polythene tunnels, higher levels of outcrossing were produced than in isolation plots with natural pollinators; the opposite result was obtained when the same flower colour was used.
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Photosynthesis research 64 (2000), S. 137-146 
    ISSN: 1573-5079
    Schlagwort(e): Brassica napus ; chlorophyll ; chlorophyll catabolite ; degradation ; porphyrin ; senescence ; tetrapyrrole
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chlorophyll catabolism accompanying leaf senescence is one of the most spectacular natural phenomena. Despite this fact, the metabolism of chlorophyll has been largely neglegted until recently. Oilseed rape has been used extensively as a model plant for the recent elucidating of structures of chlorophyll catabolites and for investigation of the enzymic reactions of the chlorophyll breakdown pathway. The key reaction which causes loss of green color is catalyzed in a two-step reaction by pheophorbide a oxygenase and red chlorophyll catabolite reductase. In this Minireview, we summarize the actual knowledge about catabolites and enzymes of chlorophyll catabolism in oilseed rape and discuss the significance of this pathway in respect to chlorophyll degradation during Brassica napus seed development.
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Euphytica 114 (2000), S. 217-221 
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; flower receptacle segments ; in vitro ; culture ; pollinated ovaries ; Raphanus sativus var. raphanistroides/kwd〉
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Oil radish (Raphanus sativus var. raphanistroides Makino) is resistant to drought and low temperature. In order to breed more resistant cultivars of rapeseed, the wide cross between rapeseed (Brassica napus L.) and oil radish was made. Rapeseed was not compatible with oil radish, and the frequency of hybrid plants (F1) was very low. Moreover, the hybrid plants were sterile. In order to recover the intergeneric hybrids (F1), the in vitro organ culture technique was applied in our experiments. The frequency of hybrid plants (F1) was increased up to 25.55% by means of in vitro culture of pollinated ovaries. Some fertile amphidiploid hybrid plants were obtained by means of colchicine treatment of small buds obtained from cultured flower receptacle segments of hybrid plants (F1). It is suggested that the technique of in vitro culture of pollinated ovaries and flower receptacle segments is useful in the wide-cross breeding of rapeseed.
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  • 15
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; fatty acid composition ; tissueculture-induced variation ; transformation-induced variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The variation obtained in storage fatty acids induced by the procedures of tissue culture and transformation with Agrobacterium tumefaciens was investigated and compared in rapeseed, Brassica napus, cv. Hanna. An increased variation in the fatty acid profiles was noted after tissue culture and transformation compared with plants derived directly from seeds. In the second generation of rapeseed transformants, T2, the content of oleic acid ranged from 39–72%, 12–31% for linoleic acid and 7–16% for linolenic acid. This could be compared with the oleic acid content in the T2 generation of tissue culture-derived plants which ranged between 47–76% and in seed-derived material where oleic acid ranged between 55–69%.In the T3 generation the ranges in transgenic seeds were decreased but still larger than in the seed derived plants. The range in transgenic plants was 49–64% for oleic acid, 20–28% for linoleic acid and 9–18% for linolenic acid. The most extreme individuals, both highest and lowest in the common fatty acids, were found in the group of transformed plants independent of generation. The total lipid content was also affected by the two treatments and seeds with the lowest and highest lipid content were both found among the transformed plants. In conclusion, care should be taken to use proper controls when performing transformation experiments in order to distinguish variation in the fatty acid profiles induced by the transformation procedure and tissue culture treatments from the changes due to transgenic expression.
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  • 16
    ISSN: 1615-6102
    Schlagwort(e): Actin microfilament ; Brassica napus ; Cytochalasin D ; Microspore embryogenesis ; Microtubule ; Preprophase band
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Changes in the actin filament and microtubule cytoskeleton were examined during heat- and cytochalasin D-induced embryogenesis in microspores ofBrassica napus cv. Topas by rhodamine phalloidin and immunofluorescence labelling respectively. The nucleus was displaced from its peripheral to a more central position in the cell, and perinuclear actin microfilaments and microtubules extended onto the cytoplasm. Heat treatment induced the formation of a preprophase band of microtubules in microspores; preprophase bands are not associated with the first pollen mitosis. Actin filament association with the preprophase band was not observed. The orientation and position of the mitotic spindle were altered, and it was surrounded with randomly oriented microfilaments. The phragmoplast contained microfilaments and microtubules, as in pollen mitosis I, but it assumed a more central position. Cytoskeletal reorganisation also occurred in microspores subjected to a short cytochalasin D treatment, in the absence of a heat treatment. Cytochalasin D treatment of microspores resulted in dislocated mitotic spindles, disrupted phragmoplasts, and symmetric divisions and led to embryogenesis, confirming that a normal actin cytoskeleton has a role in preventing the induction of embryogenesis.
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  • 17
    ISSN: 1871-4528
    Schlagwort(e): tuber soft rot ; 2n gametes ; sexual hybridization ; somatic hybridization ; germplasm exploitation ; potato
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The resistance to tuber soft rot caused byErwinia carotovora ofSolanum tuberosum x S. tarijense andS. tuberosum (+) S. commersonii hybrids and their backcrosses is reported. A number of resistant diploid sexual hybrids and tetraploid/hexaploid somatic hybrids were selected. Backcross progenies were obtained through 2x×4x crosses involving a resistant diploid hybrid and tetraploidS. tuberosum, and through 4x×4x crosses between a resistant somatic hybrid andS. tuberosum. The hybrids showed high variability interms of resistance to tuber soft rot. The resistance of progeny from 2x×4x backcrosses was similar to that of the parental sexual hybrid. By contrast, the resistance of genotypes deriving from 4x×4x backcrosses was reduced compared with the resistant somatic hybrid. In general, tuber characteristics of the backcross hybrids improved considerably as compared with their parents, and tuber yield per plant was good.
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  • 18
    ISSN: 1570-7458
    Schlagwort(e): Brassica napus ; Psylliodes chrysocephala ; glucosinolates ; jasmonic acid ; induction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Damage to the oilseed rape plant (Brassica napus L.) by the cabbage stem flea beetle, Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae) induces systemic changes to the glucosinolate profile, most noticeably an increase in the concentration of indole glucosinolates. When jasmonic acid was applied to the cotyledons of the plant, a similar effect was observed. Feeding tests with artificial substrates compared a glucosinolate fraction from jasmonic acid-treated plants with a similar fraction from untreated plants. In these tests, alterations to the glucosinolate profile increased the feeding of a crucifer-specialist feeder (P. chrysocephala). However, in whole plant tests, P. chrysocephala did not feed more on the jasmonic acid treated plants than on the controls. This implies that other aspects of the damage response are being induced by the jasmonic acid treatment and having a negative effect on subsequent herbivory.
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  • 19
    ISSN: 1573-1561
    Schlagwort(e): Oviposition-deterring pheromone ; host marking pheromone ; marker ; electrophysiology ; contact chemoreception ; gustatory sensilla ; antenna ; behavior ; Ceutorhynchus assimilis ; Coleoptera ; Curculionidae ; Brassica napus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Following oviposition into a pod of oilseed rape (Brassica napus), the female cabbage seed weevil (Ceutorhynchus assimilis) marks the pod with oviposition-deterring pheromone (ODP) by brushing it with her eighth abdominal tergite. On an unmarked pod, oviposition site selection was always accompanied by intensive antennation of the pod. Females approaching a freshly ODP-marked pod brought their antennae within 1 mm of the pod but usually did not antennate it before rejecting it for oviposition. Females with the clubs of their antennae amputated continued to discriminate pods from stems or petioles as oviposition sites but showed no behavioral response to ODP. Extracts of volatiles air-entrained from ovipositing weevils failed to inhibit oviposition. Air passed over a behaviorally active extract of ODP did not elicit a detectable electroantennogram response. By contrast, when presented as a gustatory stimulus to the sensilla chaetica of the antennal club, a behaviorally active extract of ODP from postdiapause, gravid females elicited a strong electrophysiological response. This response usually involved more than one cell and displayed a phasic–tonic time course over the recording period of 10 sec. Extract from prediapause (and hence sexually immature) females elicited neither behavioral nor electrophysiological (contact) responses. Thus the ODP of the cabbage seed weevil is sensed primarily by contact chemoreception at the sensilla chaetica of the antennae, and the electrophysiological responses recorded from these gustatory sensilla are of value as the basis of a bioassay to assist identification of the active constituent(s) of the pheromone.
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Nutrient cycling in agroecosystems 53 (1999), S. 157-175 
    ISSN: 1573-0867
    Schlagwort(e): Brassica napus ; Cicer arietinum ; current P ; Lens culinaris ; Lupinus albus ; Lupinus angustifolius ; P concentration response ; P content response ; Pisum sativum ; previous P ; sigmoid response ; single superphosphate ; Triticum aestivum ; Vicia faba ; yield response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Phosphorus (P) is a major deficiency of soils of south-western Australia (WA). The fertilizer P requirements are not known for grain legumes being evaluated for neutral to alkaline, fine textured soils in WA. To rectify this, glasshouse and field experiments were undertaken to compare the responses of several grain legume species, wheat and canola to applications of single superphosphate and the results are reported in this paper. The glasshouse experiments measured responses of dried tops, harvested at 26 to 42 days after sowing, to P that was freshly-applied (current P) and previously-applied (previous P). Responses in the glasshouse were measured using yield, P concentration and P content (P concentration multiplied by yield) of oven dried tops of the following: wheat (Triticum aestivum), canola (Brassica napus), faba bean (Vicia faba), chickpea (Cicer arietinum), lentil (Lens culinaris), field pea (Pisum sativum), albus lupin (Lupinus albus) and narrow leaf lupin (Lupinus angustifolius). Field experiments in 1994 and 1995 compared seed (grain) yield responses of faba bean, chickpea, lentil, albus lupin and wheat to applications of current P. The P was banded (drilled) with the seed while sowing at 5 cm depth. Canola and wheat produced very large yield responses to increasing applications of current P. Responses were much smaller for albus lupin, faba bean and chickpea. Responses for lentil, narrow leaf lupin and field pea, fell in between responses of the small and large seeded species. Similar trends for responses were obtained as measured using yield, P concentration, or P content. For soils treated with previous P, similar trends were observed as for current P, but differences in yield responses between species were much less marked and the response curves tended to become more sigmoid. In the field experiments, grain yield responses to current P of albus lupin and chickpea were less than that for wheat. Relative to wheat, faba bean was the most responsive grain legume to applications of current P, with lentil producing similar responses to wheat in one experiment at a newly cleared, P deficient site.
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  • 21
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; cauliflower mosaic virus ; epidermis ; gene expression ; light induction ; lipid transfer protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract cDNA and genomic clones encoding Brassica napus non-specific lipid transfer proteins (LTP) were isolated and sequenced. The encoded amino acid sequences were very similar to those reported previously for LTPs from B. napus and other species. Sequence information indicates that B. napus contains an LTP gene family. The 5′-flanking region of one gene, designated BnLTP, was fused to GUS and the fusion introduced into Arabidopsis. LTP transcripts and BnLTP-Gus expression were present predominantly in the epidermis of leaf and stem, consistent with the hypothesised function of LTPs in the deposition of cuticular or epicuticular waxes. However, GUS activity was detected in other tissues, including lateral root initials, anthers, stigmas and vascular tissues, which may suggest additional functions. LTP transcript levels in B. napus and Arabidopsis and BnLTP-GUS expression in transgenic Arabidopsis were stimulated by blue and red light but not UV-B. BnLTP promoter activity was also stimulated upon viral infection, at a time when the virus had spread systemically. No increase in expression was observed in response to cold or wounding.
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  • 22
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; cytoplasmic male sterility (CMS) ; mitochondrial gene expression ; polysomes ; post-translational degradation ; restoration of fertility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This paper describes the analysis of the effect of the restorer gene Rfo on the expression of the ORF138 protein associated with Ogura cytoplasmic male sterility (CMS) which has been engineered in rapeseed by protoplast fusion. We show that the presence of the Rfo gene in the genome of the plants decreases the amount of ORF138 protein in floral buds, this effect being the most dramatic in anthers at the stage of development when the sterile phenotype is normally expressed. However, the amount of orf138 transcripts is not affected by the Rfo gene in the same organs at the same stages. Total polysome analyses of buds and anthers show that the orf138 transcripts are translated with the same efficiency in sterile and restored plants. From these results we infer that the Rfo gene product acts on the post-translational stability of the ORF138 protein, leading to a decrease in the accumulation of the protein and a restoration of fertility.
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 216 (1999), S. 27-33 
    ISSN: 1573-5036
    Schlagwort(e): Aluminium toxicity ; Brassica napus ; canola ; root growth ; ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract There is little information on the effects of aluminium (Al) on canola (Brassica napus var. napus L.), which is a commercially important crop species in many parts of the world. In this report, we describe the effects of Al on roots of canola seedlings grown hydroponically in a nutrient solution at pH 4.5. The morphological and ultrastructural changes that accompanied these growth effects were examined. Additions to the nutrient solution of Al at concentrations below 40 μM stimulated root growth of canola seedlings, increasing both the size and number of central cap cells. The stimulation of root growth did not appear to be due to the alleviation of a proton toxicity at the root surface. At concentrations of Al above 60 μM, root growth was strongly inhibited, with cellular damage being observed primarily in peripheral root cap cells.
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  • 24
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; fatty acid composition ; intact single seeds ; NIRS ; oil content ; seed weight
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The potential of near-infrared reflectance spectroscopy (NIRS) for the simultaneous analysis of seed weight, total oil content and its fatty acid composition in intact single seeds of rapeseed was studied. A calibration set of 530 single seeds was analysed by both NIRS and gas-liquid chromatography (GLC) and calibration equations for the major fatty acids were developed. External validation with a set of 75 seeds demonstrated a close relationship between NIRS and GLC data for oleic (r = 0.92) and erucic acid (r = 0.94), but not for linoleic (r = 0.75) and linolenic acid (r = 0.73). Calibration equations for seed weight and oil content were developed from a calibration set of 125 seeds. A gravimetric determination was used as reference method for oil content. External validation revealed a coefficient of correlation between NIRS and reference methods of 0.92 for both traits. The performance of the calibration equations for oleic and erucic acid was further studied by analysing two segregating F2 seed populations not represented in the calibration set. The results demonstrated that a reliable selection for both fatty acids in segregating populations can be made by using NIRS. We concluded that a reliable estimation of seed weight, oil content, oleic acid and erucic acid content in intact, single seeds of rapeseed is possible by using NIRS technique.
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Plant growth regulation 28 (1999), S. 129-132 
    ISSN: 1573-5087
    Schlagwort(e): dormancy ; Lactuca sativa ; lettuce seeds ; Brassica napus ; rapeseed ; combustion products ; Salix viminalis ; Themeda triandra ; Triticum aestivum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In darkness, dormancy was imposed on seeds of lettuce (Lactuca sativa L. cv. Grand rapids) by high temperature and on seeds of oilseed rape (Brassica napus L. cv. Apex) by osmotic stress using polyethylene glycol (PEG 8000). In both cases, dormancy was broken by incubating the seeds in aqueous extracts of combustion products from Salix viminalis wood chips or Themeda triandra leaves. Dormancy of rapeseed, but not lettuce, was also broken by a solution of smoke from burnt straw of Triticum aestivum. The greatest stimulation from burnt vegetation was achieved with an aqueous extract of pyrolysed willow wood chips, which had been subjected to temperatures of up to 800 °C during combustion in a down-draught gasifier. This suggests that some biologically active substances obtained from combustion of plant tissues are highly heat-stable.
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  • 26
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; seed ; napin ; promoter ; gene regulation ; ABA ; ABRE
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract During seed maturation, the transcriptional activity of napin genes is regulated by developmental signals involving the transcriptional activator ABI3 and abscisic acid (ABA). To localize cis elements involved in the seed-specific activity of the napin napA promoter, a systematic analysis was performed focusing on two major element complexes, the B-box and RY/G. Substitution mutation analysis using promoter-reporter gene fusions in stable transgenic tobacco showed synergistic interactions between elements within these complexes. The distal part of the B-box shows similarities to abscisic acid response elements and the proximal portion contains a CA-rich element. In vitro studies involving Exonuclease III protection and electrophoretic mobility shift assays revealed binding by nuclear proteins to elements within the B-box. The distal and proximal parts of the B-box were found to bind distinct nuclear protein complexes. By gain-of-function analysis with a tetramer of the B-box fused to a truncated (−46) cauliflower mosaic virus (CaMV) 35S minimal promoter, it was demonstrated that the B-box mediates strong activity in seeds. Further, it was shown that the elements in the B-box constitute an ABA-responsive complex, since the B-box tetramer mediates ABA-responsiveness in vegetative tissues to a construct containing the CaMV virus 35S enhancer (−343 to −90). Thus, the seed-specific activity of the napA promoter relies on the combinatorial interaction between the RY/G complex and the B-box ABA-responsive complex during the ABA response in seed development.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 41 (1999), S. 171-180 
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; GUS ; jasmonate ; myrosinase-associated protein ; promoter ; wounding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In order to study the expression of the induced form of myrosinase-associated protein (iMyAP), a genomic clone encoding the protein was isolated from Brassica napus. The coding portion of the gene was found to consist of five exons separated by one long intron of 938 bp and three shorter introns of ca. 100 bp. A 1.9 kb promoter fragment including the 5′-untranslated region was cloned in front of the coding portion of the Escherichia coli iudA gene and transformed into Arabidopsis thaliana. Expression was observed in hypocotyls of 4-day seedlings, but in 7-day seedlings the iMyAP promoter did not direct expression. In flowering plants, only the abscission zone of the young silique displayed promoter activity. In contrast, mechanical wounding of 7-day seedlings induced a systemic expression in all cells of the cotyledons. Wounding of 14-day seedlings gave rise to systemic induced expression mainly in the vascular tissue. However, mechanical wounding and wounding by flea beetles (Phyllotreta undulata) of 4-week old plants only gave rise to a local induction of the promoter, suggesting that the systemic signal system is age-dependent. Methyl jasmonate also induced iMyAP expression. In situ and northern analysis of iMyAP transcripts in young leaves of B. napus showed that the induction was high after 1 h and absent after 24 h. Comparison of the effect of different types of wounding on the iMyAP promoter induction in transgenic Arabidopsis showed that similar degrees of local induction were achieved regardless of the degree of macerated tissue left on the plant.
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  • 28
    ISSN: 1615-6102
    Schlagwort(e): Brassica napus ; Coiled bodies ; Embryogenesis ; Germination ; Nucleolus-associated bodies ; Small nuclear RNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Nucleolus-associated bodies characterize interphase nuclei of many plant species. The recent demonstration that such bodies contain small nuclear ribonucleoproteins as well as coilin clearly indicates that they belong to a larger family of nuclear structures, known as coiled bodies, that have been intensively studied in a variety of animal cell types. In a previous work, we have shown that coiled bodies were present in close association with the nucleolus inZea mays dry seeds as well as during subsequent stages of germination. This study reveals that similar nuclear structures were also present duringBrassica napus embryogenesis starting at the torpedo stage and that they were, likewise, generally located on the nucleolar surface. As in the case ofZ. mays, coiled bodies were observed in cells of dry seeds as well as in those of early germinating tissues. These bodies were labelled with monoclonal antibody K121, an antibody reacting with the unique 5′-terminal cap structure containing 2,2,7-trimethylguanosine that characterizes small nuclear RNAs. Owing to their intimate association with the nucleolus in all stages studied, the possibility is considered that, in these plant cells, coiled bodies are assembled on an organizer element located within this organelle.
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  • 29
    ISSN: 1615-6102
    Schlagwort(e): Androgenesis ; Brassica napus ; Ploidy ; Pollen ; Rapeseed ; Somatic embryogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Embryogenic microspore and pollen culture followed by subculture of microspore-derived plantlets enabled the production of clones ofBrassica napus cv. Topas. Flow-cytometric analysis revealed that most microspore- and pollen-derived embryos (pEMs) were haploid initially. Spontaneous diploidization occurred at the globular stage of the pEMs, and was expressed as the relative increase of the 2C and 4C nuclear DNA content. Diploidization occurred throughout various organs of the pEMs and resulted in the formation of haploid and doubled haploid chimerics. In some embryos, nearly all cells were doubled haploid. From early cotyledon stage onward, pure haploid embryos were not observed anymore. At late cotyledon and germination stages, pure doubled haploid embryos and plantlets increased in number. Tetraploid pEMs were found occasionally. A culture regime was established to induce somatic embryos on the pEM-derived young plantlets. The ploidy of the somatic embryos varied highly and tended to be the same as that of the tissue at the initiation site on the pEM-plant. The results show that during the embryogenic development ofB. napus microspores, spontaneous diploidization occurs at globular stage, and increases progressively, resulting in the formation of chimerical haploid and doubled haploid plants as well as pure doubled haploid plants; ploidy neither affects pEM development at embryo developmental stages nor somatic embryogenesis, that starts on young pEM-derived plantlets; doubled haploid somatic embryos can be cloned from single pEM-derived plantlets; and doubled haploid embryos develop to fertile plants.
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  • 30
    ISSN: 1615-6102
    Schlagwort(e): Brassica napus ; Microspore embryogenesis ; Cauliflower mosaic virus 35S promoter ; Sporophytic development ; Tobacco ; Zygotic embryogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The cauliflower mosaic virus 35S (35S-CaMV) promoter, which is generally used as a constitutive promoter in plants, is known to be silent during microspore and pollen development. Here we analyzed whether the 35S-CaMV promoter fused to thegus (β-glucuronidase) gene can be used as a marker for early sporophytic development in embryogenic microspore cultures of tobacco andBrassica napus. In microspore culture ofB. napus, the 35S-CaMV promoter remained off from the start of embryogenic culture up to the mid-cotyledonary embryo stage. 35S-CaMV promoter activity was only present in those microspores that initiated sporophytic development, but failed to enter embryogenic development. Similar results were also obtained with shed-microspore cultures of tobacco, in which rapid, direct embryogenesis takes place. In isolated-microspore cultures, in which embryogenesis is delayed, an intermitting period of sporophytic development was observed, characterized by extensive 35S-CaMV promoter activity. Therefore, the 35S-CaMV promoter discriminates between two classes of sporophytic development: it is activated in microspores which change fate from gametophytic into (temporarily) nonembryogenic sporophytic development, whereas the promoter is silent in sporophytic microspores that enter embryogenic development directly. This mirrors our observation that the 35S-CaMV promoter is also silent in young zygotic embryos.
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  • 31
    ISSN: 1432-2242
    Schlagwort(e): Key words β-ketoacyl-CoA synthase ; FAE1 ; Brassica napus ; Erucic acid ; E1 locus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The synthesis of very long chain fatty acids occurs in the cytoplasm via an elongase complex. A key component of this complex is the β-ketoacyl-CoA synthase, a condensing enzyme which in Arabidopsis is encoded by the FAE1 gene. Two sequences homologous to the FAE1 gene were isolated from a Brassica napus immature embryo cDNA library. The two clones, CE7 and CE8, contain inserts of 1647 bp and 1654 bp, respectively. The CE7 gene encodes a protein of 506 amino acids and the CE8 clone, a protein of 505 amino acids, each having an approximate molecular mass of 56 kDa. The sequences of the two cDNA clones are highly homologous yet distinct, sharing 97% nucleotide identity and 98% identity at the amino acid level. Southern hybridisation showed the rapeseed β-ketoacyl-CoA synthase to be encoded by a small multigene family. Northern hybridisation showed the expression of the rapeseed FAE1 gene(s) to be restricted to the immature embryo. One of the FAE1 genes is tightly linked to the E1 locus, one of two loci controlling erucic acid content in rapeseed. The identity of the second locus, E2, is discussed.
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  • 32
    ISSN: 1432-2242
    Schlagwort(e): Key words Risk assessment ; Pollen flow ; Transgene ; Fourier transforms ; Brassica napus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  In order to help establish a basis for the assessment of gene flow associated with the large-scale release of transgenic oilseed rape, we previously designed a method which makes it possible to retrieve the average pollen dispersal of a single plant from that of a large source plot. The ‘individual’ pollen distribution thus obtained is less dependent on the experimental design than pollen distributions usually published and could therefore be used to model the possible escape of a transgene from commercial transgenic crops. In this study we report on a field experiment set up to study the pollen dispersal from an herbicide-resistant transgenic variety of oilseed rape and to test the applicability of the method on the experimental data. Two techniques were used to determine the individual pollen dispersal, and their outcomes are compared. The results suggest that approximately half of the pollen produced by an individual plant fell within 3 m and that the probability of fertilisation afterwards decreased slowly along a negative exponential of the distance. Comparison with the global pollen distribution from the source plot indicates that pollen-dispersal distributions based on dispersal from whole plots instead of individual plants would have underestimated the proportion of pollen that was dispersed over average or long distances.
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 96 (1998), S. 897-903 
    ISSN: 1432-2242
    Schlagwort(e): Key words RAPD ; Linoleic linolenic acid ; Brassica napus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Linolenic acid is a component of canola oil that is readily oxidized, which results in a reduced frying stability and shelf life of the oil. The reduction of linolenic acid in canola seed has therefore been an important breeding objective for many years. The inheritance of linolenic acid concentrations in seed oil is polygenic and is also strongly influenced by the environment. For these reasons, molecular markers are sought to assist in early and reliable selection of desired low linolenic acid genotypes in breeding programmes. Molecular markers associated with low linolenic acid loci were identified in a doubled-haploid population derived from a cross between the Brassica napus lines, ‘Apollo’ (low linolenic)×YN90-1016 (high linolenic) using RAPDs and bulked segregant analysis. A total of 16 markers were distributed over three linkage groups, which individually accounted for 32%, 14% and 5% of the phenotypic variation in linolenic acid content. The rapeseed fad3 gene was mapped near the locus controlling 14% of the variation. The mode of inheritance appeared to be additive, and a QTL analysis showed that collectively the three loci explained 51% of the phenotypic variation within this population. PCR fragments for low linolenic acid ‘Apollo’ alleles (3% linolenic acid) were identified at all three loci. Simultaneous selection for low linolenic acid ‘Apollo’ alleles at each locus resulted in a group of DH lines with 4.0% linolenic acid. The use of these makers in the breeding programme will enhance the breeding of low linolenic acid B. napus cultivars for production in Canada.
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  • 34
    ISSN: 1570-7458
    Schlagwort(e): transgenic plants ; transgenic canola ; Brassica napus ; Bacillus thuringiensis ; diamondback moth ; corn earworm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Canola (Brassica napus L.) cultivars Oscar and Westar, engineered with a Bacillus thuringiensis (Bt) cryIA(c) gene, were evaluated for resistance to lepidopterous pests, diamondback moth, Plutella xylostella L. (Plutellidae) and corn earworm, Helicoverpa zea (Boddie) (Noctuidae) in greenhouse and field conditions. In greenhouse preference assays conducted at vegetative and flowering plant stages, transgenic plants recorded very low levels of damage. A 100% diamondback moth mortality and ≈90% corn earworm mortality were obtained on transgenic plants in greenhouse antibiosis assays. The surviving corn earworm larvae on transgenic plants had reduced head capsule width and body weight. Mortality of diamondback moth and corn earworm were 100% and ≈95%, respectively, at different growth stages (seedling, vegetative, bolting, and flowering) on the transgenic plants in greenhouse tests. In field tests conducted during 1995–1997, plots were artificially infested with neonates of diamondback moth or corn earworm or left for natural infestation. Transgenic plants in all the treatments were highly resistant to diamondback moth and corn earworm larvae and had very low levels of defoliation. Plots infested with diamondback moth larvae had greater damage in both seasons as compared with corn earworm infested plots and plots under natural infestation. After exposure to defoliators, transgenic plants usually had higher final plant stand and produced more pods and seeds than non-transgenic plants. Diamondback moth injury caused the most pronounced difference in plant stand and pod and seed number between transgenic and non-transgenic plants. Our results suggest that transgenic canola could be used for effective management of diamondback moth and corn earworm on canola.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Biologia plantarum 41 (1998), S. 507-513 
    ISSN: 1573-8264
    Schlagwort(e): Brassica napus ; ex vitro acclimation ; Triticum aestivum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The greatest growth of wheat and rape plants in vitro was reached on media with 5 or 9 % sucrose, respectively. The highest efficiency for transfer of these plants to ex vitro conditions was found at the same sucrose concentrations. The content of endogenous non-structural saccharides (glucose, fructose, sucrose, starch and fructans) increased with increasing sucrose concentration in the medium up to 10 %.
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  • 36
    ISSN: 1573-8469
    Schlagwort(e): Brassica napus ; Brassica carinata ; field resistance ; pathogenicity ; plant breeding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Brassica juncea (Indian mustard) lines from diverse geographical locations around the world and from Australian breeding programs were screened for resistance to the blackleg fungus, Leptosphaeria maculans, in both glasshouse and field trials. The five Australian L. maculans isolates used in glasshouse trials could be classified into two groups; those that attacked all B. juncea lines, and those that attacked none. All these isolates caused lesions on cotyledons of B. napus cultivars including Westar, Glacier and Quinta, suggesting that they are in Pathogenicity Group 4 as described by Koch et al. (1991). The two isolates that attacked B. juncea also attacked B. napus lines to a similar extent, but did not attack the two B. carinata lines tested. Brassica lines were sown in a blackleg disease nursery at Lake Bolac, Victoria, Australia, and five indicators of blackleg disease were measured (survival rate, disease rating, disease incidence, external and internal lesion length). All 92 B. juncea lines developed blackleg symptoms. Although they displayed a high disease incidence in the field, almost all of the B. juncea lines were more blackleg-resistant than a B. napus cultivar, Dunkeld, which is amongst the most resistant cultivars in commercial production in Australia. Four B. carinata lines were more resistant than any of the B. juncea lines, suggesting that this species may be a useful source of blackleg resistance in B. napus breeding programs.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 185 (1998), S. 33-38 
    ISSN: 1573-4919
    Schlagwort(e): hsp90 ; Brassica napus ; protein kinase ; phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract A Brassica napus cDNA encoding the 90 kDa heat shock protein, hsp90, was modified to add 6 histidines at the C-terminus and expressed in insect cells to prepare a recombinant histidine-tagged hsp90. The recombinant protein was purified over Ni2+-NTA agarose columns and its identity was confirmed by Western blotting, using a plant hsp90-specific antiserum. Incubation of purified hsp90 with [γ-32P] ATP in the presence of Mn2+ resulted in its autophosphorylation on serine residues. The purified hsp90 could also phosphorylate other protein substrates such as histones and casein in the presence of Mn2+. Analysis of phosphorylated casein revealed that serine residues are phosphorylated by hsp90. This is the first demonstration that a cytosolic hsp90 homolog can phosphorylate other protein substrates.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 24 (1998), S. 2101-2114 
    ISSN: 1573-1561
    Schlagwort(e): Anemotaxis ; Ceutorhynchus assimilis ; Brassica napus ; host-plant extracts ; wind tunnel ; isothiocyanates ; α-farnesene ; trapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The effect of extracted and artificial oilseed rape (Brassica napus ssp. oleifera) odors on the behavioral response of male and female cabbage seed weevils (Ceutorynchus assimilis) was investigated in a wind tunnel. Odor-mediated upwind anemotaxis was induced by leaf extract and its artificial equivalent. Omission of two isothiocyanates from the artificial extract significantly reduced the upwind movement of females. Increasing the wind speed within the tunnel significantly reduced upwind movement in response to the odor of leaf and flower extracts. The artificial baits proved less attractive than simple extracts from oilseed rape. Field trapping confirmed that extracted leaf material was more attractive than artificial equivalents.
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  • 39
    ISSN: 1573-1561
    Schlagwort(e): Herbivore pressure ; glucosinolate ; induced response ; turnip root fly ; Delia floralis ; Brassica napus ; root damage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The effect of increasing herbivore pressure, in the form of larval feeding damage by the turnip root fly, Delia floralis, on the glucosinolate content of swede roots (Brassica napus ssp. rapifera) was investigated. Only one of the 14 root glucosinolates detected, 3-indolyl methyl glucosinolate, rose significantly with increasing levels of insect attack. Although other root glucosinolate concentrations altered following damage, the induced changes were no greater from inoculation with 20 eggs/root than with 5 eggs/root. Swedes roots that had been damaged by D. floralis contained approximately three times the concentration of total indolyl glucosinolates of control roots. This change was strongly influenced by a fourfold increase in the concentration of 1-methoxy-3-indolyl methyl glucosinolate. The total glucosinolate concentration found in swede roots remained unchanged overall as a result of a fall in the concentration of five of the aliphatic glucosinolates, which balanced the rise in aromatic glucosinolates. The relevance of these results to studies of crucifer–insect interactions are discussed.
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Nutrient cycling in agroecosystems 51 (1998), S. 35-40 
    ISSN: 1573-0867
    Schlagwort(e): ammonia emission ; ammonium ; apoplast ; Brassica napus ; compensation point ; glutamine synthetase ; Hordeum vulgare
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Barley (Hordeum vulgare L. cv. Golf) was grown in solution culture with controlled nitrogen availability in order to study the influence of nitrogen nutrition on ammonia emission from the leaves. Ammonia emission measured in cuvettes connected to an automatic NH3 monitor was close to zero for nitrate grown plants but increased to 0.9–1.3 nmol NH3 m-2 leaf area s-1 after 3–5 days of ammonium nutrition. Increasing concentrations from 0.5 to 10 mM NH4 + in the root medium increased NH3 emission from the shoots, root glutamine synthetase activity and NH4 + concentrations in apoplast, xylem sap and bulk tissue, while apoplastic pH values decreased. Inhibition of glutamine synthetase in nitrate grown barley plants by addition of 1 mM methionine sulfoximine (MSO) to the root medium caused ammonia emission to increase 5 to 10-fold after 2–3 hours. At the same time shoot tissue ammonium concentrations started to increase. Addition of an inhibitor of photorespiration, 1 mM pyrid-2-yl hydroxymethane sulfonate (HPMS) reduced this increase in ammonia emission showing a relation between NH3 emission and photorespiration. Oil seed rape (Brassica napus L. cv. Global) plants grown at 3 different nitogen levels (2N, 4N and 7N) in a sand/soil mixture showed increasing NH3 compensation points with increasing N level. This increase was highly correlated with increasing NH4 + concentrations in the leaf apoplast and total leaf tissue. The NH3 compensation points could be succesfully predicted on basis of the pH and NH4 + concentration in the leaf apoplast.
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  • 41
    ISSN: 1573-5028
    Schlagwort(e): fluorescence in situ hybridization ; Brassica napus ; S-locus ; rDNAs ; image analysis ; quantitative chromosome map
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Seventy years after Karpechenko [15] first reported the accurate chromosome number of oilseed rape (Brassica napus L., 2n=38), we have developed a quantitative chromosome map of rape using computer imaging technology. The capacity to identify individual rape chromosomes will facilitate a wide range of genetic studies. Here we demonstrate the use of imaging methods in combination with fluorescence in situ hybridization to localize, on identified chromosomes, the single copy S-locus glycoprotein and S-locus-related genes involved in the self-incompatibility system of Brassica. These techniques have a broader application in plant genome research involving the mapping of single-copy genes and markers, irrespective of the plant species.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 201 (1998), S. 149-155 
    ISSN: 1573-5036
    Schlagwort(e): Brassica napus ; cover crop ; Raphanus sativus ; Secale cereale
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Nitrogen catch crops help to reduce the loss of nitrogen from arable cropping systems during autumn and winter. The ability of catch crops to absorb nitrogen from the soil profile is affected by rate and depth of colonization of the soil by roots. The aim of the current work was to analyze total root length and root length density of catch crops in relation to above ground growth, nitrogen supply and crop species. In two field experiments roots were sampled with an auger. Experimental factors included crop species (winter rye, Secale cereale and forage rape, Brassica napus ssp. oleifera (Metzg.) Sinsk., or oil radish, Raphanus sativus spp. oleiferus (DC.) Metzg.), two sowing dates S1 and S2 (end of August and three weeks later) and two nitrogen treatments: N0, no nitrogen applied, and N1, nitrogen applied at non-limiting rate. The natural logarithm of the total root length, measured in the top 40 cm, L0–40 (km m-2), was linearly related to natural logarithm of the dry weight of the shoot, W (g m-2). There was no effect of species or sowing date on this relation. For a given W, N1 treatments showed lower values of L0–40 than N0 treatments. The decline in root length density, D (cm cm-3), with depth, X (cm), was described with the function ln D = ln D0 − qX, where D0 is the value of D at zero depth and q the linear coefficient. D0 was linearly related to L0–40, without effect of species, time of observation or N supply. The ratio D0/q, an estimate of the absolute root length, was 1.24 × L0–40. Together the relations enable estimates to be made of total root length and of root length distribution with depth using shoot dry weight of catch crops and its change with time as input. The generation of such estimates of root distribution is necessary for model studies in which the efficacy of catch crops to prevent N losses is evaluated in relation to sowing dates, distribution of N in the soil profile and the distribution of rainfall in the season.
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  • 43
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; yellow-seed coat ; B. campestris and B. carinata interspecific hybridization ; hexaploid (AABBCC) ; pentaploid (AABCC)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract To transfer the genes for yellow seed coat from both genomes A and C to B. napus (AACC), the hexaploid of Brassica (AABBCC) was synthesised from reciprocal interspecific crosses between yellow-seeded B.campestris (AA) and B.carinata (BBCC). The hexaploid with 27 pairs of chromosomes was red-seeded which showed that genic interaction existed in the trigenomic plants for the colour of the seed coat. Hundreds of hybrid seeds were obtained from crosses between the red-seeded hexaploid and partial yellow or brown-seeded varieties of B. napus as pollen donor. The majority of the hybrid plants (AABCC) were self fertile with brown seeds. It appeared that the chromosomes of the B genome were excluded during the meiosis of the pentaploid and a high proportion of the genetically balanced AC gametes could be produced. The fertility of the F2 population was increased and even reached normal levels for some plants. Seventy-three plants with the yellow-seeded character were isolated from 2590 open-pollinated F2 plants, most with increased fertility. After two successive self-pollinations, 18 lines produced yellow seeds and no brown seeds segregated from these populations. The morphology of the novel yellow-seeded plants was basically towards B. napus. Esterase isoenzyme electrophoresis showed that the plants contained some of the genetic background of B. campestris, B. carinata and B. napus. Cytological analysis has shown that at least some yellow-seeded lines have the B.napus AACC genome composition with 38 chromosomes and normal meiotic pairing.
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  • 44
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; fatty acid composition ; NIRS ; rapeseed ; reflectance spectroscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The objective of this work was to evaluate the potential of near-infrared reflectance spectroscopy (NIRS) as a rapid method to estimate the fatty acid composition of the oil in intact-seed samples of rapeseed. A total of 549 samples (3 g intact seed) from selected mutant and breeding lines were scanned by NIRS, and 220 of them were selected and scanned again by using two different adapters, which reduced the sample size to 300 and 60 mg, respectively. Selected samples were analysed by gas liquid chromatography and calibration equations for individual fatty acids were developed. Calibrations for oleic, linoleic, linolenic, and erucic acid were highly accurate, with values of r2 in cross validation from 0.95 to 0.98 (samples of 3 g), from 0.93 to 0.97 (300 mg), and from 0.84 to 0.96 (60 mg). Calibrations for palmitic and stearic acid were less accurate, with values of r2 in cross validation always lower than 0.8, probably because of the narrow range available for these fatty acids. The accuracy of the calibration equations for eicosenoic acid was very low (r2 = 0.69 in 3 g samples), although improved equations were developed (r2 from 0.78 to 0.91) when the relationship between erucic and eicosenoic acid was taken into account. We conclude that NIRS is a powerful technique to estimate the fatty acid composition of the oil in rapeseed, provided that samples covering a wide range of fatty acid levels are available, with the advantage that such estimation is possible with few additional costs when NIRS is used for the determination of other seed quality traits.
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  • 45
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; RAPD ; bulked DNA ; DNA fingerprinting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Since DNA-based markers are unaffected by environmental or physiological factors, they have potential utility in the description of plant cultivars required for award of proprietary rights (i.e. Plant Breeders' Rights). The high discriminating power of this class of markers, however, can also make demonstration of uniformity and stability of such a marker within a cultivar difficult, especially for genetically-complex cultivars. This report examines the usefulness of bulking equal quantities of DNA from 14 to 20 individuals of a cultivar to identification of RAPD DNA markers that distinguish between Brassica napus cultivars of varying genetic complexity. For the four cultivars assessed (Quantum, OAC Springfield, Innovator and AC Excel), it is shown that consistent presence/absence scores are obtained from bulked DNA samples for three different RAPD markers despite a significant degree of variation among samples from individuals. Use of bulked DNA samples thus may enable identification of a distinguishing profile of RAPD markers whose presence/absence is uniform and stable even in complex cultivars. Nevertheless, RAPD markers remain limited in that they are not strictly quantitative in nature. This limitation is discussed with respect to cultivar description for plant breeders' rights applications.
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 97 (1998), S. 431-438 
    ISSN: 1432-2242
    Schlagwort(e): Key words Targeted mapping ; RFLP ; RAPD ; Brassica napus ; Polima CMS ; Nearly isogenic line ; Bulked segregant analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  We have used two targeting approaches [pairs of nearly isogenic lines (NILs) and bulked segregant analysis] to identify DNA markers linked to the Rfp1 restorer gene for the pol CMS of canola (Brassica napus L.). We were able to target the Rfp1 locus as efficiently by comparing NILs as by bulked segregant analysis, and it was demonstrated in this instance that double-screening strategies could significantly improve the overall targeting efficiency. The chance occurrence of shared homozygosity at specific unlinked chromosomal regions in the bulks was found to limit the efficiency of bulked segregant analysis, while the efficiency of NIL comparison was limited by residual DNA from the donor cultivar at scattered sites throughout the genome of the NILs.
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  • 47
    ISSN: 1871-4528
    Schlagwort(e): potato ; mitochondria ; chloroplast ; protoplast fusion ; somatic hybridization ; cytoplasmic inheritance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Creation from 4x hybrid clones from protoplast fusion of 2x clones of potato was evaluated. Besides combined nuclear genomes, composition of the cytoplasm significantly influenced the phenotypic traits of hybrid clones. To ascertain the influence of parental cytoplasm on the success of protoplast fusion and regeneration of hybrid plants, data from 74 fusion combinations of 50 dihaploid clones were analyzed. The majority of dihaploid breeding clones belonged to the cytoplasm types Wα, Tβ and Wγ. When the closely related mt types α, β and γ were used, fusion combinations had a better combining ability compared with more distantly related cytoplasms δ and ⃛. Fusions containing the same mitochondrial type (homofusions) were not superior to closely related mitochondrial types. However, homofusions of cytoplasm type Wα yielded significantly more hybrids than homofusions of type Tβ. In general, parental cytoplasm types had little impact on the fusion combining behaviour. Thus the cytoplasm type of the fusion parents is not a suitable marker for predicting the combining ability in protoplast fusion experiments.
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  • 48
    ISSN: 1573-9368
    Schlagwort(e): pollen ; seed ; storage protein ; Brassica napus ; heterologous expression ; homologous expression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Few plant genes have been analysed in both homologous and heterologous transgenic systems. In this study, deletion mutants of the storage protein promoter napA fused to the receptor gene uidA (GUS) were analysed for their ability to direct tissue-specific expres sion in transgenic tobacco as well as transgenic Brassica napus. In seeds, qualitatively similar results have previously been obtained, demonstrating that transcription factors in the heterologous tobacco system recognized the napA promoter cis elements, more or less in the same way as in B. napus (Ellerstrom et al., 1996; Stalberg et al., 1996). However, in anthers of the transgenic plants, clear differences were noted. The napA promoter constructs were inactive in transgenic B. napus anthers. In contrast, tobacco anthers displayed activities of similar magnitudes to those previously found in the seed for the respective promoter constructs. Interestingly, in seven constructs the activity in the anthers was retained dow nstream from an imperfect ABRE element, whereas no activity could be detected in the seed. Another clear difference was that a region from −211 to −152 silenced the expression in anthers whereas this region had no effect on the activity in the seed. Likewise, in tobacco the napA promoter showed a low activity in leaves. Histochemical staining of young tobacco leaves showed that this activity was considerably higher in stomata guard cells than in the mesophyll cells while the leaves of the B. napus plants had a diffuse and barely detectable staining in the mesophyll cells. The high level of napA transcription in tobacco anthers indicates that the set of transcription factors and corresponding cis-sequences that direct tissue-specific transcription in this organ are similar to those responsible for seed-specific expression. However, comparison of the levels of expression in anthers and seeds in individual plants revealed that there was no correlation between the activities in the two organs, which suggests that positional effects influence the transcription complexes differently in seeds and anthers. Further, this study shows that careful analysis of expression directed by promoter mutants in a heterologous transformation system might reveal important cis-elements, not discernible in the tighter homologous situation
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  • 49
    ISSN: 1573-5028
    Schlagwort(e): Arabidopsis thaliana ; Brassica napus ; constans ; flowering ; zinc finger
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The Arabidopsis thaliana CONSTANS (CO) gene which promotes flowering in long days was recently isolated by chromosome walking. The mapping of QTLs controlling flowering time in Brassica species has identified genomic regions that contain homologues of the CO gene. Four genes homologous to the Arabidopsis CO gene were isolated from a pair of homoeologous loci in each of two doubled-haploid Brassica napus lines displaying different flowering times, N-o-1 and N-o-9. The four genes, BnCOa1, BnCOa9, BnCOb1 and BnCOb9, are located on linkage groups N10 and N19, and are highly similar to each other and to the Arabidopsis CO gene. Two regions of the proteins are particularly well conserved, a N-terminal region with two putative zinc fingers and a C-terminal region which may contain a nuclear localization signal. All four genes appear to be expressed in B. napus. The BnCOa1 allele was shown to complement the co-2 mutation in Arabidopsis in a dosage-dependent manner causing earlier flowering than in wild type under both long- and short-day conditions.
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 37 (1998), S. 675-687 
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; extensin ; promoter analysis ; repressors ; tensile stress ; wounding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract To identify controlling cis acting promoter regions in the B. napus extA extensin gene, expression in transgenic tobacco of 5′ −159, −433, −664, −789 and −940 bp promoter truncations linked to the uidA (B-glucuronidase) reporter coding sequence were analysed. The −159 and −433 bp truncations directed non specific expression in all cell types within the plant. An activator region which increased expression levels 10 fold in all cell types was located between −159 to −433 bp. A repressor region was found between −664 to −789 bp; removal of this region resulted in a 15 fold increase in expression. Histochemical analysis showed that transgenics containing the −664, −789 and −940 bp truncations directed expression of the fusion gene only in the phloem. A negative regulatory region located between −433 to −664 bp repressed expression in non-phloem cell types. In areas of the plant subject to tensile stress, the repression exerted by the negative regulatory region was overcome, allowing expression in all cell types. The quantitative repressor and activator regions which controlled absolute expression levels in all cell types were seperate from the negative regulatory region which controlled cell type specific expression in response to tensile stress. A wound responsive region was found to be located between −940 to −3500 bp. Thus, the extA gene is under complex control, being regulated by 4 sets of positively and negatively acting cis regions, which control wound inducibility, activation in response to tensile stress, and quantitative expression levels.
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  • 51
    ISSN: 1573-5028
    Schlagwort(e): bifunctional enzyme ; Brassica napus ; cDNA ; hydroxymethylpyrimidine phosphate kinase ; thiamin ; thiamin phosphate pyrophosphorylase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We report the characterization of a Brassica napus cDNA clone (pBTH1) encoding a protein (BTH1) with two enzymatic activities in the thiamin biosynthetic pathway, thiamin-phosphate pyrophosphorylase (TMP-PPase) and 2-methyl-4-amino-5-hydroxymethylpyrimidine-monophosphate kinase (HMP-P kinase). The cDNA clone was isolated by a novel functional complementation strategy employing an Escherichia coli mutant deficient in the TMP-PPase activity. A biochemical assay showed the clone to confer recovery of TMP-PPase activity in the E. coli mutant strain. The cDNA clone is 1746 bp long and contains an open reading frame encoding a peptide of 524 amino acids. The C-terminal part of BTH1 showed 53% and 59% sequence similarity to the N-terminal TMP-PPase region of the bifunctional yeast proteins Saccharomyces THI6 and Schizosaccharomyces pombe THI4, respectively. The N-terminal part of BTH1 showed 58% sequence similarity to HMP-P kinase of Salmonella typhimurium. The cDNA clone functionally complemented the S. typhimurium and E. coli thiD mutants deficient in the HMP-P kinase activity. These results show that the clone encodes a bifunctional protein with TMP-PPase at the C-terminus and HMP-P kinase at the N-terminus. This is in contrast to the yeast bifunctional proteins that encode TMP-PPase at the N-terminus and 4-methyl-5-(2-hydroxyethyl)thiazole kinase at the C-terminus. Expression of the BTH1 gene is negatively regulated by thiamin, as in the cases for the thiamin biosynthetic genes of microorganisms. This is the first report of a plant thiamin biosynthetic gene on which a specific biochemical activity is assigned. The Brassica BTH1 gene may correspond to the Arabidopsis TH-1 gene.
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  • 52
    ISSN: 1572-9788
    Schlagwort(e): sn-1-acylglycerol-3-phosphate acyltransferase ; Brassica napus ; cis-11 eicosenoic acid ; Escherichia coli ; triacylglycerol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The plsC gene of Escherichia coli encoding sn-1-acylglycerol-3-phosphate acyltransferase was modified by inserting an endoplasmic reticulum retrieval signal to its 3′ end and introduced into rapeseed (Brassica napus L.) plants under the control of a napin promotor. In developing seeds from transgenic plants an sn-1-acylglycerol-3-phosphate acyltransferase activity was detectable which showed substrate specificities typical of the E. coli enzyme. Moreover, seed oil from the transformants unlike that from untransformed plants contained substantial amounts of triacylglycerol species esterified with very-long-chain fatty acids at each glycerol position. Analysis of fatty acids at the sn-2 position of triacylglycerol showed hardly any very-long-chain fatty acids in untransformed plants, but in certain transformants these fatty acids were present, namely about 4% erucic acid and 9% eicosenoic acid. These data demonstrate that the bacterial acyltransferase can function in developing rapeseed and alters the stereochemical composition of transgenic rape seed oil by directing very-long-chain fatty acids, especially cis-11 eicosenoic acid, to its sn-2 position.
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  • 53
    ISSN: 1432-0983
    Schlagwort(e): Key words Trans-splicing ; nad2 ; Brassica napus ; RNA processing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The single-copy gene encoding NADH dehydrogenase subunit 2 (nad2) has been identified in the mitochondrial genome of rapeseed (Brassica napus L.). The rapeseed nad2 gene has the same gene organization in Oenothera and wheat: it consists of five exons located in two loci encoding the two first exons and the last three exons respectively. All exons are separated by group-II introns. A trans-splicing event is required to join exons B and C. Putative splicing intermediates were identified by transcriptional analysis of the nad2 gene. The complexity of organization of the nad2 gene is completely conserved even in one of the smallest mitochondrial genomes of higher plants.
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    Plant cell reports 16 (1997), S. 406-410 
    ISSN: 1432-203X
    Schlagwort(e): Brassica napus ; Brassica oleracea ; Microspore ; Embryogenesis ; Pollen development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Scanning electron microscopy was employed to study and compare microspore embryogenesis in vitro with pollen development in planta inBrassica napus andB. oleracea. An exine with its specific pattern had already been formed, when microspores were released from tetrads. During subsequent pollen development, microspores increased in size and continued to strengthen the exine. Upon in vitro culture, all microspores, i.e., embryogenic and nonembryogenic, initially showed the same morphological features. After 24 h in culture, the microspores had increased in size. Thereafter, embryogenesis was indicated in some microspores by two different morphological changes. One featured an expansion in volume of the cell cluster around the germination aperture (type I), the other showed cell cluster volume expansion over the entire microspore surface (type II). Two-thirds of embryogenic microspores in bothB. napus andB. oleracea demonstrated type I development. When followed by fluorescence microscopy, in vitro culture of microspores revealed cultures with a high embryo frequency were those with a high frequency of symmetrical division.
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  • 55
    ISSN: 1570-7458
    Schlagwort(e): cabbage seed weevil ; Ceutorhynchus assimilis ; oilseed rape ; Brassica napus ; host-plant volatile ; olfactometer ; (Z)-3-hexen-1-ol ; methyl salicylate ; nitriles ; cyanides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The cabbage seed weevil, Ceutorhynchus assimilis Payk. [syn. Ceutorhynchus obstrictus (Marsham)] (Coleoptera: Curculionidae), a crucifer-feeding insect, is a pest of oilseed rape (Brassica napus L.). It is known to be attracted by isothiocyanates, crucifer-specific volatiles that are metabolites of the glucosinolates. The responses of this insect to other electrophysiologically-active volatiles from rape were tested in a linear track olfactometer. Attraction was demonstrated to nitriles (phenylacetonitrile, 4-pentenenitrile and 5-hexenenitrile), which are also glucosinolate metabolites, and to volatiles emitted by a wider spectrum of plant families ((Z)-3-hexen-1-ol and methyl salicylate). Combination of an isothiocyanate mixture with phenylacetonitrile increased attraction, but there was no such increase when the isothiocyanate mixture was combined with methyl salicylate. A mixture of 23 volatiles, emulating an attractive air-entrainment extract of oilseed rape, was not significantly attractive, although a high proportion of weevils (60%) turned towards it. The potential of these volatiles for inclusion into an isothiocyanate-based monitoring system is discussed.
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Biology and fertility of soils 24 (1997), S. 358-364 
    ISSN: 1432-0789
    Schlagwort(e): Key words Canola ; Brassica napus ; Bacillus spp. ; P-solubilizing bacteria ; PGPR ; Rock phosphate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The ability of phosphate-solubilizing rhizobacteria to enhance the growth and phosphorus uptake of canola (Brassica napus L., cv. Legend) was studied in potted soil experiments in the growth chamber. One hundred and eleven bacteria isolated from the rhizosphere of field-grown plants, and a collection of nine bacteria known to be effective plant growth-promoting rhizobacteria (PGPR), were screened for P-solubilization in vitro. All rhizobacteria were identified using whole-cell fatty acids methyl ester (FAME) profiles. The best P-solubilizing isolates were two Bacillus brevis strains, B. megaterium, B. polymyxa, B. sphaericus, B. thuringiensis, and Xanthomonas maltophilia (PGPR strain R85). The P-solubilizers were tested for their effects on growth and P-uptake of canola plants in a P-deficient soil amended with rock phosphate. Although some of the P-solubilizing rhizobacteria significantly increased plant height or pod yield, none increased P-uptake. The most effective inoculant was a B. thuringiensis isolate which significantly increased the number and weight of pods and seed yield without rock phosphate. Xanthomonas maltophilia increased plant height, whereas the other bacilli increased the number on weight of pods. These results demonstrate the potential use of these P-solubilizing rhizobacteria as inoculants for canola, but indicate that P-solubilization was not the main mechanism responsible for positive growth response.
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 23 (1997), S. 1463-1470 
    ISSN: 1573-1561
    Schlagwort(e): Brassica napus ; oilseed rape ; Columba livia ; pigeon ; vertebrate ; herbivores ; resistance ; phenolics ; defense ; crop protection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The systemic application of L-phenylalanine (PHE), a phenolic precursor, significantly increases the phenolic pool of oilseed rape (Brassica napus var. Bristol). In a two-choice test with captive feral pigeons (Columba livia), PHE-treated plants sustained significantly less damage than control plants. This was supported by the results of behavioral studies, where video analyses showed that the PHE-treated plants received significantly fewer pecks than the controls. This is the first report of increased resistance to damage by a vertebrate pest following the systemic application of precursors for plant defense compounds.
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  • 58
    ISSN: 1573-1561
    Schlagwort(e): Dasineura brassicae ; Platygaster subuliformis ; Omphale clypealis ; parasitoids ; pest management ; oilseed rape ; Brassica napus ; Brassicaceae ; glucosinolates ; isothiocyanates ; 2-phenylethyl isothiocyanate ; allyl isothiocyanate ; host location
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The responses of Dasineura brassicae and its parasitoids Platygaster subuliformis and Omphale clypealis to allyl and 2-phenylethyl isothiocyanates have been investigated using a new design of trap in winter oilseed rape. Traps baited with allyl isothiocyanate caught more male and female D. brassicae and more female O. clypealis than traps baited with 2-phenylethyl isothiocyanate or unbaited traps, whereas traps baited with 2-phenylethyl isothiocyanate caught more male and female Platygaster subuliformis than traps baited with allyl isothiocyanate or unbaited traps. The implications of these results for host-plant and oviposition-site location by D. brassicae and for host habitat and host location by the parasitoids are discussed, as is the potential for using these responses in integrated pest management strategies.
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  • 59
    ISSN: 1573-1561
    Schlagwort(e): Honeybee ; Apis mellifera ; Hymenoptera ; Apidae ; Brassica napus ; oilseed rape ; flower volatiles ; conditioned proboscis extension ; olfactory recognition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Volatiles from oilseed rape, Brassica napus, flowers were sampled by air entrainment and their relevance to the natural odor profile of the flowers was confirmed by conditioned proboscis extension (CPE) assays with honeybee, Apis mellifera L., foragers. Coupled gas chromatography (GC)-CPE analysis of the air entrainment samples was used to locate key compounds involved in the recognition of B. napus flowers, and the compounds were then identified using coupled gas chromatography-mass spectrometry and comparison with authentic samples. Six regions of the gas chromatograms elicited CPE responses from bees previously conditioned to the total extract, and from these areas 16 compounds were identified that elicited CPE activity from conditioned bees when tested with synthetic samples. Eight of the 16, α-pinene, phenylacetaldehyde, p-cymene, α-terpinene, linalool, 2-phenyl-ethanol, (E,E)-α-farnesene, and 3-carene, gave the highest responses. When the bees were conditioned to the total extract of flower volatiles, a mixture of the eight components elicited responses from 83% of the individuals, suggesting that the eight-component mixture accounted for a major part of the CPE activity of the total extract. In addition, a mixture of the three most active compounds, phenylacetaldehyde, linalool, and (E,E,)-α-farnesene, evoked responses from 85% of the bees after the latter had been conditioned to the eight-component mixture. Thus, these three compounds appear to play a key role in the recognition of the eight component mixture and, by inference, of oilseed rape flowers.
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 23 (1997), S. 2107-2116 
    ISSN: 1573-1561
    Schlagwort(e): Brassica campestris ; Brassica hirta ; Brassica juncea ; Brassica napus ; Brassica nigra ; Lepidium sativum ; allyl isothiocyanate ; benzyl isothiocyanate ; methyl isothiocyanate ; volatiles ; phytotoxicity ; allelopathy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Several members of the crucifer family (Brassicaceae), including white mustard (Brassica hirta Moench), brown mustard [B. juncea (L.) Coss], black mustard [B. nigra (L.) Koch], leafy turnip (B. campestris L.), rapeseed (B. napus L.), and garden cress (Lepidium sativum L.) were examined for their potential as allelopathic green manure crops. Hemp sesbania [Sesbania exaltata (Raf.) Rydb. Ex A. W. Hill] germination and fresh weight was inhibited by chopped leaf tissues of all green manures tested, including wheat (Triticum aestivum L.), when added to a sandy loam soil. Wheat seed germination was inhibited only by B. nigra, B. hirta, and L. sativum, although none of the treatments reduced fresh weight of germinated seedlings. The major volatiles released by chopped plants were determined by solid-phase microextraction sampling and identified by gas chromatography–mass spectrometry (GC-MS). Volatiles included allyl isothiocyanate (allyl-ITC), 3-butenyl isothiocyanate, benzyl isothiocyanate (benzyl-ITC), cis-3-hexen-1-ol, and trans-2-hexenal. These compounds, together with methyl-ITC (methyl-ITC), β-phenylethyl-ITC, benzaldehyde, β-ocimene, and α-farnesene were tested for inhibition of seed germination of several crop and weed species when applied as volatiles. Of these, allyl-ITC and methyl-ITC were the most inhibitory, completely inhibiting the germination of all species at a headspace gas concentration of 1 ppm in airtight glass containers. Selecting mustard green manures that release high levels of allyl-ITC would appear to be optimal for allelopathic activity, and plants that produce high levels of benzyl-ITC also appear promising.
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 84 (1997), S. 183-188 
    ISSN: 1570-7458
    Schlagwort(e): Meligethes aeneus ; pollen beetle ; Coleoptera ; Nitidulidae ; Brassica napus ; oilseed-rape ; Y-tube-olfactometer ; host plant location ; epideictic pheromone ; sex determination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The response of the pollen beetle Meligethes aeneus Fab. (Coleoptera, Nitidulidae) to the volatiles of undamaged plants and conspecifics was tested in a Y-tube-olfactometer-bioassay. Beetles that had hibernated preferred significantly the volatiles emitted by their most important host plant, oilseed-rape (Brassica napus L. ‘Lorar’) in the early bud-stage. However, the odour emitted by rye (Secale cereale L.), tomato plants (Solanum lycopersicum L.), and yarrow (Achillea millefolium L.) were also attractive when tested against the corresponding growing-medium. Dock plants (Rumex obtusifolius L.) and touch-me-not (Impatiens parviflora L.) possessed no attractive properties. When tested against each other, oilseed-rape was preferred significantly by M. aeneus above all other plants, with the exception of tomato. The results indicate that M. aeneus is able to locate its host plant by olfactory stimuli in the early bud-stage, i.e. in that stage in which the infestation begins in the field and when the typical yellow colour and floral scent of oilseed-rape are absent. Female pollen beetles avoided significantly the volatiles emitted by female conspecifics and an ether extract of conspecifics of mixed sex, while volatiles from males had no significant effect on females. Furthermore, males showed no preferences when responding to conspecific odour in the olfactometer. These results suggest the existence of an epideictic pheromone for M. aeneus.
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  • 62
    ISSN: 1573-5036
    Schlagwort(e): Brassica napus ; cover crop ; radiation use efficiency ; Raphanus sativus ; Secale cereale
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In temperate climates with a precipitation surplus during autumn and winter, nitrogen catch crops can help to reduce nitrogen losses from cropping systems by absorbing nitrogen from the soil and transfer it to a following main crop. The actual and potential accumulation of dry matter and nitrogen in catch crops were studied in the field during four seasons with winter rye (Secale cereale) and forage rape (Brassica napus ssp. oleifera (Metzg.) Sinsk) or oil radish (Raphanus sativus spp. oleiferus (DC.) Metzg.). Sowing dates were end of August and three and six weeks later. Potential nitrogen accumulation, Y (g m-2), could be summarized with Y = 96 −0.34 X, where X is the day number in the year of the sowing date (range: late August till end of September). Species were compared in their performance, looking at differences in specific leaf area, leaf weight ratio, leaf area ratio, light extinction and persistence during frost. The rate of dry matter accumulation in intervals of 14 days appeared to be determined primarily by the amount of radiation intercepted. A regression, forced through the origin, gave as a common slope 1.12 g dry matter accumulated per MJ intercepted global radiation, irrespective of season, species, sowing date or nitrogen treatment (period from ca. day 250 to day 310). From this result the inference is made that leaf expansion is a key process, determining the performance of catch crop species under varying environmental conditions.
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Plant growth regulation 21 (1997), S. 153-163 
    ISSN: 1573-5087
    Schlagwort(e): amine oxidases ; arginine decarboxylase ; Brassica napus ; cadaverine ; ethylene ; osmotic stress ; ornithine decarboxylase ; polyamines
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In rape leaf discs the response to osmotic stress has been found to be associated with increases in putrescine and 1,3-diaminopropane (an oxidation product of spermidine and/or spermine) and decreases in spermidine titers. In contrast, agmatine and spermine titers showed small changes while cadaverine accumulated massively. Similar results were observed in whole rape seedlings subjected to drought conditions. α-DL-difluoromethylarginine (DFMA), a specific irreversible inhibitor of arginine decarboxylase, strongly inhibited polyamine accumulation in unstressed rape leaf discs, which suggested that the arginine decarboxylase pathway is constitutively involved in putrescine biosynthesis. In leaf discs treated under high osmotic stress conditions, both DFMA and DFMO (α-DL-difluoromethylornithine, a specific and irreversible inhibitor of ornithine decarboxylase) inhibited the accumulation of polyamines. Although the stressed discs treated with DFMA had a lower concentration of putrescine than those treated with DFMO, we propose that under osmotic stress the synthesis of putrescine might involve both enzymes. DFMA, but not DFMO, was also found to inhibit cadaverine formation strongly in stressed explants. The effects on polyamine biosynthesis and catabolism of cyclohexylamine, the spermidine synthase inhibitor, aminoguanidine, the diamine-oxidase inhibitor and γ-aminobutyric acid, a product of putrescine oxidation via diamine oxidase or spermidine oxidation via polyamine oxidase were found to depend on environmental osmotic challenges. Thus, it appears that high osmotic stress did not block spermidine biosynthesis, but induced a stimulation of spermidine oxidation. We have also demonstrated that in stressed leaf discs, exogenous ethylene, applied in the form of (2-chloroethyl) phosphonic acid or ethephon, behaves as an inhibitor of polyamine synthesis with the exception of agmatine and diaminopropane. In addition, in stressed tissues, when ethylene synthesis was inhibited by aminooxyacetic acid or aminoethoxyvinylglycine, S-adenosylmethionine utilization in polyamine synthesis was not promoted. The relationships between polyamine and ethylene biosynthesis in unstressed and stressed tissues are discussed.
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Genetic resources and crop evolution 44 (1997), S. 523-532 
    ISSN: 1573-5109
    Schlagwort(e): Brassica rapa ; Brassica napus ; electrophoresis ; genetic diversity ; isozyme analysis ; regenerationprocedure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract This investigation was conducted to assess changes in the genetic structure of two varieties of two species of annual Brassica. Seeds of B. napus cv. “Topas” and B. rapa “Broccoletto” were sent to nine research institutes in different geographical areas of Europe for regeneration. The multiplied material was sent back after one year of regeneration and analysed electrophoretically. The original populations of each species and their multiplied samples were stained for 12 different enzymes, of which 4 were found to be polymorphic (DIA, SKD, GPI and PER). It was possible to detect considerable differences in isozyme patterns in B. napus and allelic frequencies in B. rapa, both within and between populations. When the original population was compared with the regenerated samples, the Chi-square homogeneity test for all pairwise comparisons revealed distinctness with a 99% probability for B. napus and 95% probability for B. rapa with one or more of the enzyme systems examined. Furthermore, the average of gene diversity analysis (Nei, 1973) revealed that some regenerated populations have less while others have increased genetic variation compared with the original population. These observations indicated that the frequencies were non-random and considerable shifts in genetic diversity have occurred during multiplication. In addition, different regeneration procedures have caused the fixation of certain alleles.
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 188 (1997), S. 21-32 
    ISSN: 1573-5036
    Schlagwort(e): boron ; Brassica napus ; buffered solution ; chelate ; equilibrium ; nutrient solution ; resin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Chelated-buffered nutrient solutions are used for studies on micronutrient metals but so far no equivalent system exists for boron nutrition studies: the present investigation was initiated with that intention. From a literature review, it was noted that a range of substances form chelates with boron including polyhydric alcohols, sugars and phenolic compounds. However, none apart from hydrofluoric acid formed chelates with formation constants comparable to those of micronutrient metal chelates like diethylenetriaminepentaacetic acid (DTPA). Moreover, most chelating substances had deleterious side effects which reduced their possible use in water culture: many of the compounds are substrates for bacterial growth, some are harmful to handle, and others are toxic to plants or humans. Borosilicate glass; was tested in a laboratory experiment but found to release boron too slowly into solution to maintain constant boron concentration in solution even when very finely ground. Current investigations centre around the use of a boron-specific resin, which strongly complexes H3BO3 on its N-methyl glucamine functional groups. The boron sorption capacity of the resin varied from 2.2 to 5.0 mg B g-1 resin. Boron saturated resin maintained an equilibrium solution boron concentration of 46 μt M when added at the rate of 2 g of resin to 1 L of boron free triple deionised water. Plants grown in complete nutrient solution with boron saturated resin added at 1 g per litre of nutrient solution grew as well as plants grown in conventional nutrient solution containing 9.2 μt M boron and their shoots contained adequate boron concentrations for growth. There was no evidence that the resin had effects on plant growth other than in releasing and equilibrating boron concentration in the nutrient solution.
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Euphytica 98 (1997), S. 121-127 
    ISSN: 1573-5060
    Schlagwort(e): passion fruit ; Passiflora edulis f. flavicarpa ; Passiflora amethystina ; somatic hybridization ; meiotic behavior ; pollen viabilty
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Somatic hybrids (SH) obtained by protoplast fusion were investigated for meiotic behavior in order to determine their possible use in breeding programs. Flower buds from four genotypes of SH between P. edulis f. flavicarpa (E) and the wild species P. amethystina (Am) denoted SH (E + Am) # 12, # 13, # 28 and # 35 were collected and the microsporocytes analysed. Meiotic phases showed the presence of abnormalities such as univalents, bivalents and quadrivalents, laggard chromosomes and anaphase bridges. At least 14 bivalents were observed in most of the cells of the hybrid plants. The percentage of cells with quadrivalents ranged from 73.3 in (E + Am) # 13 to 93.3 in (E + Am) # 28 and # 35. Analysis of pollen viability (V) indicated V = 88.23% for # 12, V = 83.86% for # 13, V = 84.20% for # 28, and V = 72.90% for # 35, and fruit development was observed. The high pollen viability, together with the multivalent pairing observed in the four somatic hybrids indicates that these materials can be used for the genetic improvement of yellow passion fruits aiming at introgressions of genes for resistance to diseases and pests.
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Euphytica 93 (1997), S. 163-168 
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; embryo rescue ; intergeneric hybridization ; ovary culture ; Sinapis alba ; rapeseed ; yellow mustard
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Researchers have conclusively shown that Sinapis alba (commonly known as yellow mustard) has many agronomic traits which would be beneficial if transferred to rapeseed ( Brassica napus L.). S. alba is resistant or tolerant to all major insect pests of Brassica crops in the Pacific Northwest region of the United States of America. It is also tolerant of high temperatures and drought stress, is shatter resistant and capable of high seed yield without the need for insecticides and herbicides. However, S. alba is considerably lower in oil content and lacks the high oil quality and seed meal quality of rapeseed (i.e. canola). This paper describes a combination of ovary culture and embryo rescue techniques used to develop fertile hybrid plants from the intergeneric cross between S. alba and B. napus . The hybrids were intermediate between both parents for presence of trichomes, leaf shape and color, seed size, pod shape, and seed oil content; showing expression of traits from both parental species. Hybrid plant tissue and seed contained all types of glucosinolate that exists in either B. napus or S. alba, at the same or higher level to the parental species. These hybrid crosses offer the potential for combining the desirable oil and glucosinolate qualities of B. napus with insect and disease resistance characters of S. alba.
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Euphytica 93 (1997), S. 339-343 
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; linolenic acid ; protoplast fusion ; rapeseed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Brassica napus somatic hybrids with low linolenic acid (18:3) content in their seed oil have been produced using fusion partners screened for low 18:3. One somatic hybrid contained only 3.5% 18:3, a level significantly below the mid-parental mean. The low level of 18:3 proved stable in the R1 generation. Oil content of the lowest 18:3 selection increased from the mid-parental mean (29.3%) in the R0 generation to 36% in a R1 field bulk. The R1 field population also showed some resistance to shattering.
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  • 69
    ISSN: 1573-5060
    Schlagwort(e): potato ; Solanum nigrum complex ; somatic hybridization ; hybrid selection criterions ; cell-selectable markers ; DNA content
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Fusion experiments were performed between diploid (2n = 2x = 24) or tetraploid (2n = 4x = 48) potato genotypes and four species of the Solanum nigrum complex, namely S. nigrum (2n = 6x = 72), S. villosum (2n = 4x = 48), S. chenopodioides (2n = 2x = 24) or S. americanum (2n = 2x = 24 and 2n = 6x = 72). All five accessions of the S. nigrum-species were successfully hybridized with at least one of the potato genotypes. Somatic combining abilities were influenced by the ploidy level as well as the genotype of the parental species. The use of kanamycin or hygromycin resistance as cell-selectable markersystem had no influence on somatic combining ability, but such markers can be useful to improve efficient selection of somatic hybrids in sufficient numbers. At least 20% of the hybrids of each successful combination performed well in vitro. However, only 60 genotypes out of 761 somatic hybrids were vigorous as well as flowering in the greenhouse. Analysis of the DNA content of somatic hybrids could be used as a criterion for the indirect selection in vitro of hybrids that were vigorous in the greenhouse. Flowering somatic hybrids of S. nigrum (+) 2x potato and S. americanum (+) 4x potato were selected with the aim of introgression of resistance traits after recurrent backcrossing with cultivated potato.
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Euphytica 98 (1997), S. 53-58 
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; cross prediction ; heterosis ; swede
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract From an experiment involving swede (Brassica napus ssp. rapifera L.) material resulting from a 4 × 4 diallel cross and a 4 × 9 factorial mating design better parent heterosis for dry matter and marketable yield was found in the majority of the hybrids. For breeders preference the better parent heterosis was not that pronounced and the majority of the hybrids were inferior when compared to their better parent. The generation means showed that models containing the mean, m, and the dominance parameter, h, generally resulted in the best fit. In some cases the additive parameter, d, improved the fit. In those cases, however, the additive parameter was substantially smaller than the dominance parameter. The probability of occurrence of recombinant inbred lines that outperform the source F1-hybrid was, with very few exceptions, found to be low. Implications for swede breeding are discussed.
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 33 (1997), S. 821-834 
    ISSN: 1573-5028
    Schlagwort(e): leaf senescence ; genes ; gene expression ; subtractive hybridisation ; Brassica napus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A subtractive hybridisation technique was developed to clone cDNAs representing genes that showed enhanced expression during leaf senescence in Brassica napus. A number of different genes were identified that, when analysed by northern hybridisation, showed different patterns of expression during leaf development but were all expressed at increased levels during senescence. Sequence analysis of these cDNAs showed that several types of genes were found including two different proteases, glutamine synthetase, ATP sulphurylase, catalase, metallothionein, ferritin and an antifungal protein. The possible roles of these gene products in the senescence process are discussed.
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  • 72
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; complementation ; DNA polymerase δ ; DNA replication ; proliferating cell nuclear antigen (PCNA) ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A cDNA encoding the proliferating cell nuclear antigen (PCNA) from Brassica napus (oilseed rape) was shown to complement the lethal deletion mutation in the PCNA gene (ΔPOL30) of Saccharomyces cerevisiae. We provide unequivocal evidence that the B. napus PCNA can perform all the essential functions of the yeast PCNA in DNA replication, although some species-specific differences may exist. In addition, the B. napus PCNA expressed as a fusion polypeptide with glutathione S-transferase (GST) was shown to stimulate the activity and processivity of two δ-like DNA polymerases from wheat in vitro. These experiments provide direct biochemical evidence that the B. napus PCNA may function as an auxiliary factor in plant cell DNA replication.
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  • 73
    ISSN: 1432-2242
    Schlagwort(e): Key words Self-incompatibility ; Brassica oleracea ; Brassica napus ; RFLP ; PCR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Self-incompatibility (SI) in Brassica is a sporophytic system, genetically determined by alleles at the S-locus, which prevents self-fertilization and encourages outbreeding. This system occurs naturally in diploid Brassica species but is introduced into amphidiploid Brassica species by interspecific breeding, so that in both cases there is a potential for yield increase due to heterosis and the combination of desirable characteristics from both parental lines. Using a polymerase chain reaction (PCR) based analysis specific for the alleles of the SLG (S-locus glycoprotein gene) located on the S-locus, we genetically mapped the S-locus of B. oleracea for SI using a F2 population from a cross between a rapid-cycling B. oleracea line (CrGC-85) and a cabbage line (86-16-5). The linkage map contained both RFLP (restriction fragment length polymorphism) and RAPD (random amplified polymorphic DNA) markers. Similarly, the S-loci were mapped in B. napus using two different crosses (91-SN-5263×87-DHS-002; 90-DHW-1855-4×87-DHS-002) where the common male parent was self-compatible, while the S-alleles introgressed in the two different SI female parents had not been characterized. The linkage group with the S-locus in B. oleracea showed remarkable homology to the corresponding linkage group in B. napus except that in the latter there was an additional locus present, which might have been introgressed from B. rapa. The S-allele in the rapid-cycling Brassica was identified as the S29 allele, the S-allele of the cabbage was the S 5 allele. These same alleles were present in our two B. napus SI lines, but there was evidence that it might not be the active or major SI allele that caused self-incompatibility in these two B. napus crosses.
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  • 74
    ISSN: 1615-6102
    Schlagwort(e): Brassica napus ; Embryo sac ; Freeze substitution ; High pressure freezing ; Ovule ; Petunia x hybrida
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In order to improve the ultrastructural preservation of the female gametophyte ofPetunia x hybrida andBrassica napus we tested several cryofixation techniques and compared the results with those of conventional chemical fixation methods. Ovules fixed with glutaraldehyde and osmium tetroxide in the presence or absence of potassium ferrocyanide showed poor cell morphological and ultrastructural preservation. In ovules cryo-fixed by plunging into liquid propane, the cell morphology was well preserved. However, at the ultrastructural level structure-distorting ice crystals were detected in all tissues. Due to the large size of the ovules, cryofixation by plunging in liquid propane is not adequate for ultrastructural studies. In contrast,P. x hybrida andB. napus ovules cryo-fixed by high pressure freezing showed improved cell morphological as well as ultrastructural preservation of the embryo sac and the surrounding integumentary tissues. The contrast of the cellular membranes after freeze substitution with 2% osmium tetroxide and 0.1% uranyl acetate in dry acetone was high. At the ultrastructural level, the most prominent improvements were: straight plasma membranes which were appressed to the cell walls; turgid appearing organelles with smooth surface contours; minimal extraction of cytoplasmic and extracellular substances. In contrast to the chemically fixed ovules, in high pressure frozen ovules numerous microtubules and multivesicular bodies could be distinguished.
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  • 75
    ISSN: 1572-9788
    Schlagwort(e): Brassica napus ; bulked segregant analysis ; marker assisted selection ; Ogura restorer ; RAPD
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Bulked segregant analysis was used to identify RAPD markers in oilseed rape (Brassica napus L.) that were linked to a male fertility restorer gene for Ogura cytoplasmic male sterility. After screening for polymorphisms using 960 primers, 14 RAPD markers were mapped to a 25 cM region including the restorer locus, a mapping population of 242 F2 individuals being employed. The map was used to select 11 markers that were investigated for polymorphisms between the restorer donor line and 46 recipient lines. A set of four RAPD markers, one in coupling phase with the restorer allele and three with the non-restorer allele, which were informative in all 46 combinations, were used in marker assisted selection of plants homozygous for the restorer allele. A total of 906 homozygous restored plants were found among the 4605 BC1F2 plants analysed. Phenotypic data of a subset of the classified plants was compared with the RAPD data and the expected number of recombinants was calculated from the map data. A close correspondence between the expected and observed numbers of plants with a deviating phenotype was found. Thus, use of a set of dominant RAPD markers provides a way obtaining reliable data for marker-assisted selection.
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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Transgenic research 6 (1997), S. 279-288 
    ISSN: 1573-9368
    Schlagwort(e): Agrobacterium tumefaciens ; Brassica napus ; wintercultivar ; transformation ; GUS ; hygromycin ; kanamycin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An efficient protocol for Agrobacterium tumefaciens-mediated transformation of six commercial Brassica napus winter cultivars is described. Two B. napus spring cultivars were analysed for comparison. Five strains of A. tumefaciens with different combinations of nopaline and octopine chromosomal backgrounds and virulence plasmids were used for cocultivation. Selection of putative regenerated transgenic plants was performed on kanamycin- or hygromycin-containing media. The scores of transgenic plants were calculated on the basis of GUS (β-glucuronidase) activity, detected by the histochemical X-Gluc test. Target tissue derived from the cut surface of cotyledon petioles resulted in successful transformation with all the winter cultivars tested. Target tissue from hypocotyl segments resulted in a successful transformation with only one winter cultivar. The transformation rates for B. napus winter cultivars in this study were higher than in previous reports. Southern blot analysis revealed that integration of marker genes occurred in single and in multiple copies and at multiple loci in the genome. The transgenic plants all grew normally and developed fertile flowers after a vernalization period. After self-pollination, Southern blot analysis of selected GUS active F1 plants revealed that introduced marker genes were stably inherited to the next generation. These data demonstrate that morphologically normal, fertile transgenic plants of B. napus winter cultivars can be achieved with both nopaline- and octopine-derived A. tumefaciens strains. This protocol should have a broad application in improvement of Brassica napus winter cultivars by introduction of foreign genes
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  • 77
    ISSN: 1573-5028
    Schlagwort(e): nuclear-mitochondrial interaction ; mitochondrial malate dehydrogenase ; Brassica napus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two-dimensional analyses of mitochondrial proteins of Brassica napus revealed a set of differences in patterns of mitochondrial matrix proteins isolated from different nuclear backgrounds. One of these varying proteins was identified as mitochondrial malate dehydrogenase (mMDH; EC 1.1.1.37) by homology analyses of the partial amino acid sequence. Immunological detection identified additional mMDH subunits and detected different patterns of mMDH subunits in two distinct mitochondria types although they were isolated from plants with the same nuclear genotype. These differences are also reflected in isozym patterns, whereas Southern analyses showed no alteration in genome structure. Therefore mitochondria type-specific mMDH modifications are possible.
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  • 78
    ISSN: 1432-2048
    Schlagwort(e): Brassica napus ; Colchicine ; Heat shock ; Microspore embryogenesis ; Microtubules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Prior to this report, heat treatment (32.5°C, 24 h) was the method used to induce embryogenesis fromBrassica napus microspores. Continuous culture at 25°C results in pollen development. This study shows that colchicine alone, at the non-inductive temperature of 25°C, can induce embryogenesis, thus demonstrating that heat shock is not required for embryogenic induction inB. napus cv. Topas. Embryogenic frequencies of over 15% were obtained by culturing isolated microspores with 25 μM colchicine for 42 h at 25°C. The microspore developmental stages responsive to colchicine were unicellular vacuolate and late unicellular, somewhat earlier stages than the population responsive to heat induction. Other groups have reported that heat-shock proteins are essential to the induction of embryogenesis. The present study offers a method of embryogenic induction without the use of heat which will allow discrimination between the factors associated with response to heat shock and those involved with changing cell development.
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  • 79
    ISSN: 1432-203X
    Schlagwort(e): Brassica napus ; Chromosome doubling ; Colchicine ; Doubled haploids ; Microspore embryogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This report describes a very high genome doubling efficiency of Brassica napus cv. Topas plants, derived from microspores induced to undergo embryogenesis with a colchicine treatment, without the use of a heat treatment. The plants showed normal growth and development, and 90% were fertile. In contrast, only 6% of the plants derived from heat-induced embryos were fertile diploids. All cytological analysis of the progeny of fertile plants showed 2n=38 chromosomes. These results show that colchicine can simultaneously induce microspore embryogenesis and double the ploidy level to produce doubled haploid plants.
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 92 (1996), S. 382-387 
    ISSN: 1432-2242
    Schlagwort(e): Genetics ; Blacking resistance ; Brassica napus ; Brassica juncea ; Leptosphaeria maculans
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genetic control of adult-plant blackleg (Leptosphaeria maculans) resistance in a Brassica napus line (579NO48-109-DG-1589), designated “R13” possessing Brassica juncea-like resistance (JR), was elucidated by the analysis of segregation ratios in F2 and F3 populations from a cross between “R13” and the highly blackleg-susceptible B. napus cultivar “Tower”. The F2 segregration ratios were bimodal, demonstrating that blackleg resistance in “R13” was controlled by major genes. Analysis of the segregation ratios for 13 F3 families indicated that blackleg resistance in these families was controlled by three nuclear genes, which exhibited a complex interaction. Randomly sampled plants of F3 progeny all had the normal diploid somatic chromosome number for B. napus. The similarities between the action of the three genes found in this study with those controlling blackleg resistance in B. juncea is discussed.
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  • 81
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; Cultivar identification ; DNA fingerprinting ; Anchored SSR ; PCR ; Silver staining
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Primers complementary to simple sequence repeats (SSRs) and with variable three-base ‘anchors’ at their 5′ end, were used in PCR analyses to compare pooled DNA samples from various Brassica napus and B. rapa cultivars. Amplification products were resolved on polyacrylamide gels and detected by silver-nitrate staining. The resulting banding patterns were highly repeatable between replicate PCRs. Two of the primers produced polymorphisms at 33 and 23 band positions, respectively, and could each discriminate 16 of the 20 cultivars studied. Combined use of both primers allowed all 20 cultivars to be distinguished. The UPGMA dendrogram, based on the cultivar banding profiles, demonstrated clustering on the basis of winter/spring growth habit, high/low glucosinolate content, and cultivar origin (i.e. the breeder involved). Intracultivar polymorphism was investigated using a minimum of ten individuals for each cultivar and was found to vary considerably between cultivars. It is concluded that anchored SSR-PCR analysis is a highly informative and reproducible method for fingerprinting oilseed rape populations, but that intra-cultivar variation should be investigated before using banding profiles from pooled samples for the identification of individuals.
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 93 (1996), S. 282-286 
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; RFLP linkage map ; QTL ; Erucic acid ; Linolenic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The quality of plant oil is determined by its component fatty acids. Relatively high levels of linolenic acid reduce the oxidative stability of the oil, and high levels of erucic acid in the diet have been associated with health problems. Thus, oilseed Brassica napus cultivars with low linolenic and low erucic acid contents are highly desirable for edible oil production. In order to identify genes controlling the levels of erucic and linolenic acids, we analyzed the oil composition of 99 F1-derived doubled haploid lines from a cross between cv ‘Major’ (high levels of erucic and linolenic acids) and cv ‘Stellar’ (low levels of both fatty acids). A molecular marker linkage map of 199 loci for this population was used to identify quantitative trait loci (QTL) controlling oil composition. We identified two regions that accounted for nearly all of the phenotypic variation in erucic acid concentration and one region that accounted for 47% of the variation in linolenic acid concentration. The QTL associated with linolenic acid concentration mapped near a RFLP locus detected by a cDNA clone encoding an omega-3 desaturase, suggesting that the low linolenic acid content of ‘Stellar’ may be due to a mutation in this gene.
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  • 83
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; L. Genetic mapping ; RFLP and RAPD markers ; Segregation distortions ; Comparative mapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have undertaken the construction of a Brassica napus genetic map with isozyme (4%), RFLP (26.5%) and RAPD (68%) markers on a 152 lines of a doubled-haploid population. The map covers 1765 cM and comprises 254 markers including three PCR-specific markers and a morphological marker. They are assembled into 19 linkage groups, covering approximatively 71% of the rapeseed genome. Thirty five percent of the studied markers did not segregate according to the expected Mendelian ratio and tended to cluster in eight specific linkage groups. In this paper, the structure of the genetic map is described and the existence of non-Mendelian segregations in linkage analysis as well as the origins of the observed distortions, are discussed. The mapped RFLP loci corresponded to the cDNAs already used to construct B. napus maps. The first results of intraspecific comparative mapping are presented.
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  • 84
    ISSN: 1432-203X
    Schlagwort(e): Brassica napus ; Ogura cytoplasmic male sterility ; Protoplast fusion ; Cold tolerance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Twenty-one cold-tolerant, male sterile Brassica napus somatic hybrids were produced by protoplast fusion. The fusion partners were a coldsensitive, Ogura cytoplasmic male sterile cauliflower inbred (B. oleracea var. botrytis inbred NY7642A) and a cold-tolerant, fertile canola-type B. rapa cv. Candle. Hybridity was confirmed by morphology, isozyme expression, flow cytometry, and DNA hybridization. Organellar analyses revealed a very strong bias for Brassica over Raphanus chloroplasts. Cold tolerance was confirmed by cold chamber studies and chloroplast DNA analyses. Good female fertility with 21.4 ± 3.1 seeds/pod was observed in the field using natural pollination vectors. Total seed yield was significantly greater for the atrazine-sensitive somatic hybrids produced in this study than for atrazine-resistant isolines.
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 81 (1996), S. 277-284 
    ISSN: 1570-7458
    Schlagwort(e): host-plant choice ; Brassica napus ; B. juncea ; B. nigra ; Sinapis alba
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Oviposition behaviour of Meligethes aeneus F. (Coleoptera: Nitidulidae) is characterised and quantified on four different plant species. Six behavioural components are identified: W—walking, WA—walking with abdomen on surface, R—resting, B—biting, AOH—placing abdomen over the bite hole and OVI—oviposition. Comparison of host acceptance behaviours on Brassica napus L., Brassica juncea (L.) Czern, Brassica nigra (L.) Koch and Sinapis alba L. showed that S. alba was accepted as a host only after a long exposure to the plant. Behaviour on the Brassica species was similar, however on B. nigra beetles spent a high proportion of time actually ovipositing. We conclude that important cues for oviposition are located both on the bud surface and inside the bud.
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 206-208 
    ISSN: 1570-7458
    Schlagwort(e): Meligethes aeneus ; Brassica napus ; Raphanus raphanistrum ; secondary plant metabolites ; plant genetics ; biosynthesis ; isothiocyanates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 228-230 
    ISSN: 1570-7458
    Schlagwort(e): 2-phenylethylglucosinolate ; secondary plant metabolites ; Brassica napus ; Cruciferae ; salicylic acid ; Homoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 179 (1996), S. 25-33 
    ISSN: 1573-5036
    Schlagwort(e): abscisic acid ; Brassica napus ; Brassica carinata ; callus ; photosynthesis ; plant growth ; salinity ; salt tolerance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The greater sensitivity of B. carinata to salinity in comparison to B. napus has been linked to a greater reduction in net assimilation rate. Apparently this is not due to ion toxicity; the cause is unknown. In this report, we test the hypothesis that increases in abscisic acid (ABA) are involved in the reduction of growth by salinity. Salinity (8 dS m−1) caused an increase of ABA concentrations in the shoot, root and callus of both species. ABA concentrations were lower in the salt-tolerant species, B. napus, than the salt-sensitive species, B. carinata, both in the whole plant and callus. Leaf expansion for both species was equally sensitive to ABA; salt stress did not significantly alter sensitivity to applied ABA. The growth inhibition increased in a hyperbolic manner with an increase in endogenous ABA concentration. These results indicate that ABA in salt-stressed plants may play a role in the inhibition of growth. The photosynthesis of salt-sensitive species, B. carinata, was also decreased by salinity, corresponding to the reduction in growth. The decreased photosynthesis does not appear to be the cause of the growth reduction, because photosynthesis was not inhibited by short-term exposure to salinity and photosynthesis was poorly correlated with endogenous ABA concentrations.
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  • 89
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 181 (1996), S. 307-316 
    ISSN: 1573-5036
    Schlagwort(e): allelochemicals ; Brassica napus ; germination ; glucosinolates ; isothiocyanates ; rapeseed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Enzymatic hydrolysis of glucosinolates, a class of compounds found in Brassica species, results in a number of products with potential to inhibit seed germination. To investigate the impact of both volatile and water-soluble allelochemicals, germination bioassays using Lactuca sativa seeds were conducted with root and combined leaf and stem tissues of Brassica napus. Tissues in which glucosinolates were hydrolyzed to remove volatile glucosinolate degradation products were compared with intact tissues and water controls. Only tissues containing glucosinolates produced volatiles that inhibited germination. Volatiles were trapped and identified using GC-MS. Volatiles produced in greater quanitity from intact tissues than from tissues without glucosinolates were almost exclusively glucosinolate hydrolysis products. Water-soluble components also inhibited germination. Chemical analysis of extracts confirmed the presence of glucosinolate hydrolysis products, but indicated the involvement of additional allelochemicals, especially in leaf and stem tissues. Results support the proposal that glucosinolate-containing plant tissues may contribute to reductions in synthetic pesticide use if weed seeds are targeted.
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  • 90
    ISSN: 1573-5036
    Schlagwort(e): B deficiency diagnosis ; boron (B) ; Brassica napus ; critical B concentration ; functional B requirement ; leaf elongation ; oilseed rape ; shoot growth
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Plant analysis can diagnose boron (B) deficiency when the standards used have been properly developed by establishing that a close relationship exists between B concentration in a plant part and its physiological function. The purpose of the present study was to demonstrate the importance of choosing the growing immature leaves for B deficiency diagnosis and for establishing critical B concentrations for the diagnosis of B deficiency in oilseed rape (Brassica napus). In Experiment 1, the plants were subject to seven levels of B supply using programmed nutrient addition, for the estimation of critical B concentrations in plant parts for shoot growth. In Experiment 2, the plants were treated with two levels of B supply in solution: 10 (+B) and 0 (-B) μM B, for the estimation of functional B requirements for leaf elongation. The results showed that critical B concentrations varied amongst the plant parts sampled and decreased with leaf age. As B taken up by roots is largely phloem-immobile, B concentrations in mature leaves are physiologically irrelevant to plant B status at the time of sampling, giving rise to a significant over- or underestimation of the B requirement for plant growth. By contrast, a growing, immature leaf, in this case the youngest open leaf (YOL), was the most reliable plant part for B deficiency diagnosis. Critical B concentrations developed from both methods were comparable-i.e. 10–14 mg B kg−1 dry matter in the YOL at vegetative growth stages up to stem elongation.
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  • 91
    ISSN: 1573-5060
    Schlagwort(e): doubled haploid ; gene mapping ; genetic control ; linolenic acid ; mutant ; plant breeding ; RAPD ; rape seed ; Brassica napus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The inheritance of the low linolenic acid content (derivated from mutant lines) in rapeseed was investigated. Molecular techniques of gene mapping through RAPD markers were applied on a microspore-derived progeny from a high × low linolenic acid F1 hybrid. ‘Bulked segregant analysis’ made it possible to test rapidly number of RAPD primers. Two linkage groups of 6 markers (72.7 cM and 75.6 cM) were determined. Each corresponded to a major QTL which explained 24% and 30.7% of the total phenotypic variation of the linolenic acid content. It was confirmed that two independant mutations were implied in the low linonenic acid content.
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 30 (1996), S. 679-684 
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; cis-acting element ; cold-inducible gene ; enhancer ; G-box ; LTRE
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Mutation of the core pentamer, CCGAC, of two putative low temperature responsive elements (LTREs) in the 5′-proximal region of the winter Brassica napus cold-induced gene BN115 was carried out. Analyses of transient expression of the resultant mutated BN115 promoter-GUS fusions revealed the loss of low-temperature regulation by the promoter. This indicates that the CCGAC sequence is critical to the low-temperature response in the BN115 gene. In contrast, mutation of two G-boxes, CACGTG, staggered between the LTREs in the same region of the promoter did not alter cold-inducible gene expression. Replacement of a possible enhancer region of the BN115 promoter with the enhancer from the CaMV 35S promoter resulted in a several-fold increase in low temperature-induced GUS activity.
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  • 93
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; cell wall protein ; cold-induced gene ; hybrid-proline-rich protein ; low temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have isolated a gene and cDNA from Brassica napus encoding a hybrid-proline-rich protein. The putative protein is modular in structure. The N-terminal domain has properties of a signal peptide which would direct the protein into the ER. Amino acids 27 to 287 comprise three domains which contain high levels of proline and several other amino acids common in proline-rich cell wall proteins. These domains are characterised by repeating amino acid motifs. The C-terminal domain (amino acids 288 to 376) contains three putative membrane-spanning regions and shows a high degree of amino acid similarity to known hybrid-proline-rich proteins from several species. It is likely that the protein is secreted from the cell, located in the cell wall and anchored in the plasma membrane via the C-terminal domain. Transcripts encoding this protein are induced in leaf tissue within 8 h of cold treatment and decrease rapidly when plants are returned to normal temperatures. The transcripts are not induced by heat shock, dehydration, exogenous ABA or wounding, whereas transcripts of a control B. napus gene are induced by dehydration and ABA. The possible function of this protein in cold tolerance is discussed.
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  • 94
    ISSN: 1573-5028
    Schlagwort(e): polygalacturonase isoforms ; Brassica napus ; pod dehiscence ; pod shatter
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Seven distinct partial cDNAs, similar in sequence to previously described polygalacturonases (PGs), were amplified from cDNA derived from rape pod wall, dehiscence zone and leaves by the polymerase chain reaction. Northern analysis showed that one clone, PG35-8, was expressed at low levels in the dehiscence zone during the first five weeks after anthesis but was very abundantly expressed at week 6. In contrast, no PG35-8-related RNA was detected in the pod wall. Our data suggest that there are temporal and spatial correlations between the breakdown of the middle lamella, of the dehiscence zone cells and the pattern of synthesis of PG35-8 transcripts which may indicate a role for this particular PG in rape pod dehiscence. PG35-8 was used to isolate five cDNA clones from a rape dehiscence zone cDNA library. Restriction enzyme analysis and partial sequencing revealed that they were derived from four highly homologous transcripts which are probably allelic forms of a single gene. One full-length clone, RDPG1, was completely sequenced. The predicted protein of RDPG1 showed its highest identity with PG from apple fruit with an identity of 52%.
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  • 95
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; deletion analysis ; napin ; promoter ; seed ; storage protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The promoter region (−309 to +44) of the Brassica napus storage protein gene napA was studied in transgenic tobacco by successive 5′ as well as internal deletions fused to the reporter gene GUS (β-glucuronidase). The expression in the two main tissues of the seed, the endosperm and the embryo, was shown to be differentially regulated. This tissue-specific regulation within the seed was found to affect the developmental expression during seed development. The region between −309 to −152, which has a large effect on quantitative expression, was shown to harbour four elements regulating embryo and one regulating endosperm expression. This region also displayed enhancer activity. Deletion of eight bp from position −152 to position −144 totally abolished the activity of the napA promoter. This deletion disrupted a cis element with similarity to an ABA-responsive element (ABRE) overlapping with an E-box, demonstrating its crucial importance for quantitative expression. An internal deletion of the region −133 to −120, resulted in increased activity in both leaves and endosperm and a decreased activity in the embryo. Within this region, a cis element similar to the (CA)n element, found in other storage protein promoters, was identified. This suggest that the (CA)n element is important for conferring seed specificity by serving both as an activator and a repressor element.
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  • 96
    ISSN: 1573-5036
    Schlagwort(e): Brassica napus ; canola ; oilseed rape ; nitrogen nutrition ; irrigation ; photosynthesis ; photosynthetic nitrogen use efficiency
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The rate of photosynthesis and its relation to tissue nitrogen content was studied in leaves and siliques of winter oilseed rape (Brassica napus L.) growing under field conditions including three rates of nitrogen application (0, 100 or 200 kg N ha-1) and two levels of irrigation (rainfed or irrigated at a deficit of 20 mm). The predominant effect of increasing N application under conditions without water deficiency was enhanced expansion of photosynthetically active leaf and silique surfaces, while the rate of photosynthesis per unit leaf or silique surface area was similar in the different N treatments. Thus, oilseed rape did not increase N investment in leaf area expansion before a decline in photosynthetic rate per unit leaf area due to N deficiency could be avoided. Much less photosynthetically active radiation penetrated into high-N canopies than into low-N canopies. The specific leaf area increased markedly in low light conditions, causing leaves in shade to be less dense than leaves exposed to ample light. In both leaves and siliques the photosynthetic rate per unit surface area responded linearly to increasing N content up to about 2 g m-2, thus showing a constant rate of net CO2 assimilation per unit increment in N (constant photosynthetic N use efficiency). At higher tissue N contents, photosynthetic rate responded less to changes in N status. Expressed per unit N, light saturated photosynthetic rate was three times higher in leaves than in silique valves, indicating a more efficient photosynthetic N utilization in leaves than in siliques. Nevertheless, from about two weeks after completion of flowering and onwards total net CO2 fixation in silique valves exceeded that in leaves because siliques received much higher radiation intensities than leaves and because the leaf area declined rapidly during the reproductive phase of growth. Water deficiency in late vegetative and early reproductive growth stages reduced the photosynthetic rate in leaves and, in particular, siliques of medium- and high-N plants, but not of low-N plants.
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 30 (1996), S. 597-609 
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; chitinase ; leaf senescence ; plant development ; PR proteins ; PR1-a
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Genes that are expressed during leaf senescence in Brassica napus were identified by the isolation of representative cDNA clones. DNA sequence and deduced protein sequence from two senescence-related cDNAs, LSC94 and LSC222, representing genes that are expressed early in leaf senescence before any yellowing of the leaves is visible, showed similarities to genes for pathogenesis-related (PR) proteins: a PR-1a-like protein and a class IV chitinase, respectively. The LSC94 and LSC222 genes showed differential regulation with respect to each other; an increase in expression was detected at different times during development of healthy leaves. Expression of both genes was induced by salicylic acid treatment. These findings suggest that some PR genes, as well as being induced by pathogen infection, may have alternative functions during plant development, for example in the process of leaf senescence.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 30 (1996), S. 1291-1300 
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; ethylene ; extensins ; organ-specific gene regulation ; wounding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have analysed the expression of the endogenous extensin genes in Brassica napus, using northern hybridisation and dot blotting. In the unstressed plant, the extA gene is only expressed in the root, expression in the leaf, petiole and stem being absent. We have found that wounding dramatically alters this normal pattern of expression. Expression in wounded leaf is seen after 36 h, in wounded petioles after 11 h and in wounded stem after 17 h. Differences in the amount of extensin mRNA accumulated are also seen: wounded petiole accumulating extensin message to a level higher than the leaf or the stem. Inhibitors of ethylene biosynthesis greatly delay the onset of accumulation of extensin mRNA in wounded tissues. Wounding the root causes the level of extensin message to decline with time, until levels below the limit of non-specific hybridisation are reached 11 h after wounding. Thus, application of the wounding stimulus results in the accumulation of extensin gene transcripts to different degrees and at different times in the aerial parts of the plant, and results in a decline in the same transcripts in the roots. Extensin transcript accumulation as a result of wounding is also dependent on the age of the tissue; high levels of message are seen in old wounded leaves, while expression in young wounded leaves is absent.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 99
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; CDP-choline ; cytidylyltransferase ; freezing stress ; phosphatidylcholine ; yeast mutant complementation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract CTP: phosphocholine cytidylyltransferase is a rate-limiting enzyme in biosynthesis of phosphatidylcholine in plant cells. We have isolated four cDNAs for the cytidylyltransferase from a root cDNA library of Brassica napus by complementation in a yeast cct mutant. The deduced amino-acid sequences of the B. napus enzymes resembled rat and yeast enzymes in the central domain. Although all cytidylyltransferases ever cloned from B. napus and other organisms were predicted to be structurally hydrophilic, the yeast cct mutant transformed with one of the B. napus cDNA clones restored the cytidylyltransferase activity in the microsomal fraction as well as in the soluble fraction. These results are consistent with a recent view that yeast cells contained a machinery for targeting the yeast cytidylyltransferase to membranes, and may indicate that the B. napus enzyme was compatible with the machinery.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 100
    ISSN: 1573-5036
    Schlagwort(e): Brassica napus ; Festuca arundinacea ; Hibiscus cannibinus ; Lotus tenuis ; phytoremediation ; salinity ; selenium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract High levels of naturally occurring selenium (Se) are often found in conjunction with different forms of salinity in central California. Plants considered for use in phytoremediation of high Se levels must therefore be salt tolerant. Selenium accumulation was evaluated for the following species under increasing salt (NaCl and CaCl) conditions:Brassica napus L. (canola),Hibiscus cannibinus L. (kenaf),Festuca arundinacea L. (tall fescue), andLotus tenuis L. (birdsfoot trefoil). The experimental design was a complete randomized block with four salt treatments of 〈1, 5, 10, and 20 dS m-1, four plant species, three blocks, and six replicates per treatment. Ninety days after growing in the respective salt treated soil with a Se concentration of 2 mg Se kg-1 soil, added as Na2SeO4, all plant species were completely harvested. Among the species tested, shoot and root dry matter yield of kenaf was most significantly (p〈0.001) affected by the highest salt treatment and tall fescue and canola were the least affected species. Generally there was a decrease in tissue accumulation of Se with increasing salt levels, except that low levels of salinity stimulated Se accumulation in canola. Canola leaf and root tissue accumulated the highest concentrations of Se (315 and 80 mg Se kg-1 DM) and tall fescue the least (35 and 7 mg Se kg-1 DM). Total soil Se concentrations all harvest were significantly (p〈0.05) lower for all species at all salt treatments. Removal of Se from soil was greatest by canola followed by birdsfoot trefoil, kenaf and tall fescue. Among the four species, canola was the best candidate for removing Se under the tested salinity conditions. Kenaf may be effective because of its large biomass production, while tall fescue and birdsfoot trefoil may be effective because they can be repeatedly clipped as perennial crops.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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