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EN
The objective of this study was to standardize an induction strategy of chromosome aberrations in maize inbred line L-869. Pollen grains irradiated with 0, 36 and 72 Gy were used for fertilization. Resulting seeds were planted in a greenhouse to assess the number of abnormal meiotic cells. Germination, height, sterility and mortality were verified. Cells with delayed separation of chromosomes, translocation, deficiency, abnormal pairing, later condensation and anaphase bridges were observed. The number of abnormalities increased as the dosage increased but chromosome aberration types were the same regardless of the dosages used. Various chromosome-altered plants were obtained without viability loss.
EN
Pollen proteases were discovered over 100 years ago, whereas the enzymes from female tissues have been used since the Roman era in simple biotechnological processes. In the last decade a great progress has been made in studies on plant proteases, including those from the generative organs. This paper reviews reports published in the last decade, concerning purification, properties and localization of proteases from generative parts of flowering plants against the background of the general proteolytic machinery of the plant. Special attention is paid to differences in protease structure and properties in comparison to other enzymes from the same catalytic classes. Participation of the proteases in all steps of pollen-pistil interaction as well as in pollen tube growth is discussed. Further intensive studies with use of native substrates are necessary to understand the role of proteases in pollination.
EN
Microspores cultured in vitro can be reprogrammed to divide and produce a bipolar embryo. The reaction to stress treatment is a signal for inducing the sporophytic pathway, preventing the development of fertile pollen grain ? the gametophytic pathway. The ultimate goal is to convert each microspore from a heterozygous F1 plant to a doubled haploid plant so that a population of doubled haploids fully represents the genetic variability of the preceding meiosis.
EN
The cultivated American species Lupinus mutabilis was selected in order to assess its possibilities of being introduced as an alternative high protein crop in Polish conditions. The realized programme involved identification of earlier maturing and higher yielding genotypes as well as interspecific hybridization with lupins belonging to section Albus, which includes the oldest cultivated species Lupinus albus. Recent reports (1) on determination of DNA polymorphism by the PCR method indicate usefulness of direct application of small amounts of pollen. The advantage of this method is the precisely determined and physiologically stable material used for the analysis. Furthermore, pollen can be preserved above the hygroscopic substance at ?20oC for a long time and small amounts of pollen (20-100 grains) can be used for the analysis without any damage to the plant material. For PCR reaction, ten selected primers were used. A polyacrylamide gel comparison of the PCR products revealed that random primers as well as primers which amplified a fragment of the whole gene can be applied to analyse the DNA of polymorphism of L. mutabilis and L. albus. The conclusion is that it is possible to differentiate within both groups of species by application of pollen to DNA analysis.
EN
The aim of the present study was to find the reasons a low fertility of plants with duplicated segments of the short arms of satellited chromosomes.An attempt was made to determine the influence of duplicated segments of different size on the course of meiotic division, pollen stainability and viability as well as to evaluate the influence of these traits on seed setting in barley lines carrying duplications.Material for the study were spring barley (Hordeum vulgaris) lines, derived from the cv.Bonus with structural changes in chromosomes 6 and 7.It was found that percentage of bivalents formed in the course of meiotic division is correlated with the size of a duplicated sector.The formation of quadrivalent chromosome linkages in the course of meiosis was observed in the lines with duplications, and the number of quadrivalents per cell increased with an enlarged size of a duplicated chromosome sector.Seed setting in the lines carrying duplications may be negatively affected by a small amount of pollen grains in the anthers.Per cent of fertile flowers in the group of lines with duplications was not directly correlated either with per cent of viable pollen grains or with the size of a duplicated sector.
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