小麦单细胞再生植株后代染色体与DNA变异的初步研究

Preliminary Studies on Chromosome Variation and Change of DNA in Progenies of Regenerated Plants from Single Cell Culture In Vitro in Wheat

为了使体细胞无性系变异更好地应用于作物品种改良,以小麦单细胞培养再生植株后代为材料,研究了其染色体和DNA的变异。结果表明,再生植株后代与未经培养的亲本相比,花粉母细胞减数分裂染色体行为发生异常,终变期染色体数目和体细胞染色体数目发生变化,而且早期世代变异幅度大。但随着繁殖世代的增加,花粉母细胞减数分裂染色体行为和体细胞染色体数目的变化渐趋稳定,至第五代基本稳定。对农艺性状已稳定的再生植株第九代不同株系总DNA进行RAPD-PCR扩增,结果表明,不同株系与未经培养的亲本相比在DNA水平上存在变异,出现亲本特异性谱带缺失,该类株系表现为矮秆、早熟。

The chromosome variation and change of DNA were studied by using the progenies of regenerated plants derived from the single cell culture in vitro in wheat, to study the changes of genetic variation in the progenies derived from the regeneration plants, and to provide theoretical evidence for using somaclonal variation in crop improvement. The results showed that the chromosome behavior of pollen mother cell at meiosis was abnormal, the chromosome number of pollen mother cell at diakinesis and somatic chromosome number changed in progeny regenerated plants, compared with the uncultured parent. The range of changes was very wide in the early generations. Along with the increase of generation in the propagation of regeneration plants, the change of chromosomal behavior of pollen mother cell at meiosis and somatic chromosome number were stable gradually, and the changes were not stable until the fifth generation. The total DNA from the different lines in the ninth generation derived from the regeneratied plants with stable agronomic characters was amplified by RAPD-PCR. The results showed that the variation at the level of DNA existed, and deletion of the special bands in different lines from the regeneratied plants were observed compared with the uncultured parent. The lines with deletion of special DNA band have lower height and earlier maturity.