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  • Artikel: DFG Deutsche Nationallizenzen  (5)
  • Primula  (3)
  • Pollen viability  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 4 (1991), S. 104-109 
    ISSN: 1432-2145
    Schlagwort(e): High humidity and temperature stress ; Nicotiana tabacum ; Tobacco ; Pollen viability ; Vigour ; Semi-vivo technique
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Responses of pollen grains of Nicotiana tabacum to high humidity (95% RH, 4 h) and temperature (38°/45° C, 4 h) stresses were investigated. Pollen grains were subjected to only RH or only temperature, or to both of these stresses. Their viability was assessed on the basis of the fluorochromatic reaction (FCR) test, and vigour was assessed on the basis of the time taken for in vitro germination as well as on the emergence of pollen tubes through the cut end of semi-vivo implanted styles. None of the stress conditions affected pollen viability and high RH or high temperature stress did not individually affect pollen vigour. However, pollen vigour was markedly affected when both the stresses were given together. Pollen grains subjected to high RH at 38° C took a longer time to germinate in vitro and the pollen tubes emerged later from the cut end of the semi-vivo styles; division of the generative cell was also delayed. Pollen grains subjected to high RH at 45° C failed to germinate in vitro, but did germinate on the stigma. Many pollen tubes subjected to this treatment showed abnormalities, and the growth of pollen tubes in the pistil was much slower than that observed in other treatments. Pollen samples subjected to all of the stress conditions were able to induce fruit and seed set. The implications of these results on the relationship between the FCR test and viability, and between viability and vigour, especially in stressed pollen, are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 3 (1990), S. 225-227 
    ISSN: 1432-2145
    Schlagwort(e): Crotalaria retusa ; Oils ; Pollen storage ; Pollen viability ; Pollen vigour
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Attempts were made to store pollen grains of Crotalaria retusa L. in a mineral oil (paraffin oil) and two vegetable oils (soybean oil and olive oil). Under laboratory conditions pollen grains not stored in oil lost in vitro germinability within 15–30 days, while those stored in oils maintained some degree of germinability even after 60 days. Pollen samples stored in oils at −20° C did not show any decline in germinability or pollen tube vigour even after 6 months of storage. The results amply demonstrate the feasibility of using oils for short- and long-term pollen storage.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1615-6102
    Schlagwort(e): Breeding system ; Heterostyly ; Pollen-stigma interaction ; Self-incompatibility ; Pollen hydration ; Pollen membranes ; Primula
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The pollens from pin (long-styled) and thrum (short-styled) flowers ofPrimula differ markedly in water economy. While pin pollen is little affected by atmospheric humidity, the germinability of thrum pollen in liquid medium is sensitive to the conditions experienced during the immediately preceding period, being depressed when the grains are partly desiccated, although capable of being restored with subsequent controlled rehydration. The tubes produced by incompletely rehydrated thrum pollen show abnormal growth forms, suggesting that the effect is on the membranes of the vegetative cell, a conclusion supported by observations on membrane state using the fluorochromatic reaction. Thrum pollen stripped of part of the material carried in the cavities of the exine by rinsing with a lipid solvent loses much of its capacity for the uptake of atmospheric water, indicating that, in this morph, some factor facilitating hydration is transferred from the sporophytic parent during pollen maturation. Implications of these differences in the physiology of the pin and thrum pollens for the functioning of the intramorph-incompatibility system are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1615-6102
    Schlagwort(e): Breeding system ; Heterostyly ; Pollen-stigma interaction ; Pollen tube growth ; Primula ; Self-incompatibility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The stigmas of the heterostylous genusPrimula are of the “dry” type without a free-flowing surface secretion. The papillae of the stigma surface cells of the two morphs, in pin (stigma exserted) and thrum (stamens exserted), bear a thin proteinaceous surface pellicle, overlying a discontinuous cuticle. The vacuoles of the papillate cells contain tannins, and tannin cells extend in files through the stigma heads and form a loose sheath surrounding the pollen-tube transmitting tract in the styles. The cells of the transmitting tissue in the stigma heads have a normal complement of organelles, and abundant ribosomal endoplasmic reticulum. The intercellular spaces contain an internal secretion which reacts cytochemically for both carbohydrate and protein. The transmitting tract in the styles forms a central core surrounded by several vascular strands. The cells are elongated, and the intercellular spaces here also have a carbohydrate-protein content. In a compatible pollination, thrum pollen tubes enter the stigma by penetrating the cuticle at the tip or on the flank of the pin papilla. Pin tubes on the thrum stigma enter between adjacent papillae, penetrating the thin cuticle at the base. The tubes grow through the transmitting tracts in the intercellular material.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    ISSN: 1615-6102
    Schlagwort(e): Breeding system ; Heterostyly ; Pollen-stigma interaction ; Pollen tube growth ; Primula ; Self-incompatibility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In incompatible (intramorph) pollinations of the heterostylousPrimula vulgaris, pollen germination or tube growth may be partially inhibited in several sites associated with the stigma or style. Blockage may occur, a) on the stigma surface through the failure of germination or of pollen tube penetration after germination, b) in the stigma head during the passage of the tube through the specialized transmitting tissue of the head, or c) in the transmitting tract of the style. None of the barriers is complete, and the prohibition of selfing or intramorph crossing depends upon the cumulative screening effect of one following upon the other. In both morphs, the germination of incompatible pollen on the stigma is enhanced in high ambient relative humidity, but many tubes still fail to penetrate the stigma. Those that do are retarded or blocked in their growth in the transmitting tissues of the stigma head and style. Crude extracts from the tissues of the stigma head and style show some differential effect on the growth of pollen tubesin vitro, and dialysates of extracts containing high molecular weight fractions show a consistent differential effect, those from thrum tissues retarding thrum tubes while having a lesser effect on pin tubes, and those from pin tissues retarding pin tubes while having lesser effect on thrum. It is suggested that the factors influencing tube growth are present in the intercellular secretions of the transmitting tract.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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