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Microspore embryogensis ? the stress induced change of gametophytic into sporophytic development

100%

Cegielska-Taras T.

Biotechnologia

2004

nr 2

12-16

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.

The course of meiosis, pollen fertility and seed setting in barley lines with duplications in chromosomes 6 and 7

100%

Sodkiewicz T. , Sodkiewicz W.

nr 4

231-240

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.