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  • Triticum aestivum  (7)
  • Calocoris angustatus  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 66 (1983), S. 111-121 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Agropyron ; Intergeneric hybrids ; Embryo culture ; Chromosome pairing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Intergeneric hybrids of Triticum aestivum (2n=42,AABBDD) with Agropyron ciliare (2n= 28,SSYY), A. trachycaulum (2n=28,SSHH), A. yezoense (2n=28,SSYY) and A. scirpeum (2n=28) are reported for the first time. F1 hybrids of T. aestivum were also produced with A. intermedium (2n=42,E1E1E2E2Z1Z1) and A. junceum (2n=14,JuJu). All wheat-Agropyron hybrids were obtained by embryo rescue technique. Cultivars and reciprocal crosses differed for seed set, seed development and F1 plant production. The F1 hybrids were sterile. Attempts to obtain amphiploids were unsuccessful. However, backcross derivatives were obtained with wheat as the recurrent parent. The level of chromosome pairing in A. trachycaulum x wheat, A. yezoense x wheat and wheat x A. junceum hybrids provided no evidence of homologous or homoeologous pairing. Mean pairing frequencies in A. ciliare x wheat, wheat x A. scirpeum and wheat x A. intermedium hybrids indicated homoeologous or autosyndetic pairing. Ph gene was more effective in regulating homoeologous pairing in A. yezoense x wheat hybrids than in A. ciliare x wheat hybrid. Chromosome pairing data of BC1 derivatives indicated that either some of the wheat chromosomes were eliminated or Agropyron chromosomes caused reduced pairing of wheat homologues.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Agropyron caninum ; Elymus caninus ; Intergeneric hybrids ; Chromosome pairing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Intergeneric hybrids were produced between common wheat, Triticum aestivum (2n=6x=42, AABBDD) and wheatgrass, Etymus caninus (Agropyron caninum) (2n=4x=28, SSHH) — the first successful report of this cross. Reciprocal crosses and genotypes differed for percent seed set, seed development and F1 hybrid plant production. With E. caninus as the pollen parent, there was no hybrid seed set. In the reciprocal cross, seed set was 23.1–25.4% depending upon wheat genotype used. Hybrid plants were produced only by rescuing embryos 12–13 days post pollination with cv ‘Chinese Spring’ as the wheat parent. Kinetin in the medium facilitated embryo germination but inhibited root development and seedling growth. The hybrids were vigorous, self sterile, and intermediate between parents. These had expected chromosome number (2n=5x=35, ABDSH), very little chromosome pairing (0.51 II, 0.04 III) and some secondary associations. The hybrids were successfully backcrossed with wheat. Chromosome number in the BC1 derivatives varied 54–58 with 56 as the modal class. The BC1 derivatives showed unusually high number of rod bivalents or reduced pairing of wheat homologues. These were sterile and BC2 seed was produced using wheat pollen.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 71 (1994), S. 101-109 
    ISSN: 1570-7458
    Keywords: sorghum ; sorghum bicolor ; head bug ; Calocoris angustatus ; Mirid ; insect density ; plant resistance ; food availability ; seasonal effects ; genotypic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Studies were undertaken on interactions between panicle size, insect density, host plant, and the environment for sorghum head bug,Calocoris angustatus Lethiery on five sorghum genotypes in terms of bug population increase, grain damage and loss in grain mass across four panicle sizes (5, 10 or 20 branches/panicle and whole panicle), and three infestation levels (5, 10 and 15 pairs of bugs/panicle). Head bug numbers increased and grain damage decreased with an increase in panicle size in the head bug susceptible cultivars, CSH 1 and CSH 5. However, the increase in bug numbers or decrease in grain damage was not significant in head bug resistant genotypes, IS 17610 and IS 17645. Head bug numbers increased with an increase in infestation level in CSH 1 and CSH 5, however, such an increase was not substantial in IS 17610 and IS 17645. Grain damage was significantly lower in IS 17610 and IS 17645 compared with CSH 1 and CSH 5 across infestation levels. Head bug population increased at a greater rate during the rainy season compared with the dry season. Panicle size and infestation levels accounted for greater variation in grain damage and percentage loss in grain mass during the rainy season than in the dry season. To identify reliable sources of resistance to insects, it is important to study insect host plant-interactions across panicle sizes (levels of food availability), infestation levels and seasons.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 285-294 
    ISSN: 1570-7458
    Keywords: Head bug ; Calocoris angustatus ; sorghum ; resistance mechanisms ; preference ; antibiosis ; consumption and utilization of food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les mécanismes de la résistance du sorgho à la punaise C. angustatus ont été examinés au champ et au laboratoire. Les préférences des adultes ont été examinées avec choix multiples au champ et au laboratoire sur les 5 cultivars relativement moins sensibles (IS 2761, IS 9692, IS 17610, IS 17618, IS 17645) comparés aux hybrides commerciaux très sensibles (CSH 1, CSH 5, CSH 9). Les différences ont été confirmées avec des choix binaires au laboratoire. L'absence de préférence pour un cultivar est une des composantes de la résistance du sorgho à la punaise. Mais l'absence de préférence n'est cependant pas prouvée en cage au champ au par des expériences en olfactomètre sans choix au laboratoire. La ponte a été étudié sur 8 ‘génotypes’ pendant la saison des pluies de 1983 et sur 6 génotypes pendant la saison des pluies et après celle-ci en 1983–84. Les résultats montrent que la réduction de la ponte est une composante importante de la résistance sur IS 17645, IS 17610 et IS 17618. Pour définir le niveau d'antibiose, l'étude du cycle a été menée au laboratoire sur 5 cultivars relativement peu sensibles (IS 2761, IS 9692, IS 17610, IS 176618, IS 17645) et 3 sensibles (CSH 1, CSH 5, CSH 9). Le développement post-embryonnaire est prolongé d'un jour au deux quand les larves sont élevées sur grains laiteux de IS 17610 ou IS 17645. Les larves de 5e stade et les adultes ont des poids plus faibles sur IS 17610 et IS 9692. Les indices de consommation et d'utilisation des aliments ont été calculés pour IS 2761, IS 6984, CSH 5 et Swarna; l'utilisation de grains de IS 2761 et IS 69884, comparée aux grains des cultivars CSH 5 et Swarna, est relativement moins efficace. C1 et GR sont plus faibles sur grains d'IS 2761 de 20 jours que de 12 jours.
    Notes: Abstract Cultivar preference/nonpreference for feeding is one of the components of resistance to the sorghum head bug, Calocoris angustatus Lethiery (Hemiptera: Miridae). IS 2761, IS 9692, IS 17610, IS 17618 and IS 17645 were not preferred by the adults of c. angustatus under multi- or two-choice conditions. However, cultivar preference was not evident under no-choice tests or headcage conditions. Reduced oviposition is an important component of resistance to head bugs in IS 17645, IS 17610 and IS 17618. Post-embryonic development was extended by 1–2 days when nymphs were fed on these genotypes. Fifth instar nymphs and adults had lower weights when reared on IS 17610 and IS 9692. Nymphal survival was relatively lower on IS 9692, IS 17610 and IS 17645. Fourth instar nymphs were relatively less efficient in food utilization when fed on grain of IS 2761 and IS 6984 as compared with the susceptible cultivars CSH 5 and Swarna. Stage of grain development influenced the indices of consumption and utilization of food by head bugs. Consumption index (CI) and growth rate was lower on 20-day-old grain of IS 2761 as compared with 12-day-old grain.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 24 (1991), S. 233-236 
    ISSN: 1573-5044
    Keywords: anther culture ; cultivars ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Twenty-two cultivars and lines of winter and spring wheat (Triticum aestivum L.) were studied, most for the first time, for their anther culture response. The response was genotype dependent. Plants grown in the field gave higher callus induction frequency than those grown in the greenhouse and the controlled environment chamber. Donor plants grown in a season of low drought stress as compared to a season of severe drought stress resulted in a higher frequency of callus induction. Spherical microcalli were observed in two wheat genotypes in some of only those anthers that were placed with only one loculus in contact with the medium. Wheat lines that were more responsive to anther culture were identified.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 49 (1990), S. 209-214 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Agropyron spp. ; embryo rescue ; wide crosses ; crossability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Soft winter wheat lines were crossed with Agropyron intermedium, A. elongatum and A. trichophorum using pollen from single plants of Agropyron spp. to pollinate wheat spikes. Not only species but also individual plants within varieties of Agropyron species differed in percent seed set with a wheat genotype. In two arrays of crosses between two phenotypically different plants of A. elongatum and nine wheat lines, one Agropyron plant gave higher seed set (overall=27.1%) than the other (overall=3.7%). The differences were significant in seven of the nine cross combinations. Results are consistent with the hypothesis that these two plants differ in their crossability as pollen parents with wheat, and suggest the possibility of occurrence of crossability genes in wheatgrasses. The success rate of hybrid embryo rescue was higher (87.5%) with cold treatment (4°C) than without cold treatment (75.0%) of excised embryos on culture media. Results underscore the significance of genotype of the alien species for crossing with low crossable wheats, and of the physical factors for improving embryo rescue in wide crosses.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 36 (1987), S. 161-165 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; winter wheat ; vernalization ; cold treatment ; immature embryos ; excised embryos ; embryo culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of direct vernalization of immature embryos on flowering was studied in six winter wheat genotypes. Fourteen-, 17-, and 20-day-old embryos were excised and vernalized for 0–6 weeks on synthetic medium during a conditioning period. Percent germination of embryos was high (overall 96.1%), and free from genotypic effects. Genotypes differed for flowering in response to cold treatment of excised embryos. Embryo vernalization was as effective as or more than conventional vernalization (control, seedling vernalization for 6 weeks). Seventeen-day-old embryos were the most responsive to vernalization. With a 5-week vernalization of 17-day-old embryos, the percentage of plants anthesed was higher than those from 14-and 20-day-old embryos. For 17-day-old embryos vernalized for 5 weeks, the mean number of days from culture to anthesis was less than that of 6 week vernalization, less than that of 14- and 20-day-old embryos, and less than controls.
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  • 8
    ISSN: 1573-5060
    Keywords: Calocoris angustatus ; host-plant ; resistance ; fecundity ; grain damage ; sorghum ; sorghum head bug ; Sorghum bicolor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Sorghum head bug (Calocoris angustatus Leth.) (Hemiptera: Miridae) is an important pest of grain sorghum in India. We studied the fecundity of head bug females reared for one to three generations on head bug-resistant and head bug-susceptible genotypes during the 1988 and 1989 rainy and 1988–89 post-rainy seasons. Head bug population increase was lower for the first, second and/or third generation when the bugs were reared on IS 2761, IS 19955, IS 14334, IS 23748, IS 16357, IS 17610, and IS 21444 compared with the susceptible controls CSH 1, CSH 5, and CSH 9. These genotypes also suffered a low grain damage (damage rating (DR) ≤5) (except IS 2761) compared with the susceptible controls (DR〉6). A marginal decrease in fecundity was observed when the bugs were reared on IS 2761, IS 14334, IS 16357, IS 20740 and IS 17610 and then transferred to the susceptible control, CSH 1. Sorghum genotypes having lower increase in bug population across generations, suffering low grain damage, and showing adverse effects on fecundity can be used in breeding for resistance to head bugs.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-5044
    Keywords: Triticum aestivum ; wide crosses ; tissue culture ; somaclonal variation ; Agropyron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Segments of young inflorescences of Triticum aestivum cv. Chinese Spring (CS), its F1 hybrids with Agropyron trachycaulum and A. scirpeum and backcross derivatives with A. yezoense, A. intermedium and A. junceum, and of a A. yezoense x T. aestivum cv. Wichita hybrid were cultured. Different parts of young spikelets of A. trachycaulum x CS F1 and A. yezoense x Wichita F1 's were also cultured. Percent callus induction was lower in wheat than in the wheat-Agropyron hybrids or backcross derivatives. Percent callus induction from different organs in both hybrids was in the descending order of whole spikelet, spikelet without glumes, rachis, and glumes. No plants could be regenerated from calli of wheat and backcross derivatives except those of CS x A. intermedium combination. Callus induction in hybrids varied from 54 to 84% and plant regeneration from 14 to 31%. The regenerants required no vernalization. Variants including one with top-dense spikes and another with elongated spikelets were recovered. Out of eight A. trachycaulm x CS hybrid regenerants, one had anthers and stigma as opposed to neutral flowers of the original hybrid.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 31 (1982), S. 629-634 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; winter wheat ; vernalization ; cold treatment ; immature embryos ; excised embryos ; kinetin ; nutrient media ; seedling growth ; plant growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Embryo age and composition of nutrient medium affected plant growth and response to vernalization in winter wheat (Triticum aestivum L.). Root and shoot development was more in older than in younger excised embryos, and more in a medium without kinetin than in one with kinetin. Kinetin (2 mg/l) in the medium did not accelerate vernalization, probably because it tended to inhibit seedling and plant growth. Embryo age and media did not completely replace vernalization. Twenty- and 16-day-old embryos responded by flowering after 4 weeks of vernalization. Among plants raised on a standard medium from 20-day-old embryos and vernalized for 4 weeks, 84.2% flowered by or before 50 days after transplanting. Time from embryo culture to heading for 20-day-old embryos with-4-week vernalization averaged 84.6 days. Immature embryos (16–20 days old) needed only 4 weeks of vernalization compared to 6 weeks for mature embryos. Excised embryos could be vernalized as efficiently as seedlings raised by embryo culture. Embryo culture at 16–20 days after anthesis coupled with 4-week cold treatment shortens generation time of winter wheat by about 40 days.
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