Gordeeva E I, Leonova I N, Kalinina N P, Salina E A, Budashkina E b
Genetika. 2009 Dec;45(12):1616-26.
A total of 40 introgressive lines of common wheat (2n = 42) Triticum aestivum L x T. timopheevii Zhuk., resistant to brown rust and partly to powdery mildew, were examined. Based on cytological analysis of meiosis in pollen mother cells (PMC), hybrid lines were subdivided into two groups characterized by either stable or unstable meiosis. In cytologically stable lines, chromosome configuration at the MI stage of meiosis was mostly bivalent (21II) with small proportion of defect cells (almost 10%), which at most contained two univalents (20II + + 21). Cytologically unstable group was comprised of the lines, containing high proportions of cells with abnormal chromosome pairing in meiotic PMC, as well as the cells with multivalents, and the lines containing aneuploid plants. Localization of the T. timopheevii fragments performed with the use of SSR markers showed that the lines with unstable meiosis were characterized by higher numbers of introgressions compared to stable lines. The influence of certain chromosomes of T. timopheevii on chromosome pairing stability was also demonstrated. In cytologically unstable lines, the increased frequency of 2A substitutions along with the high frequency of introgression of T. timopheevii genetic material into chromosome 7A was observed. Multivalents were scored in all cases of introgression in chromosome 7A. It was suggested that the reason for the genome instability in hybrid forms lied in insufficient compensating ability of certain T. timopheevii chromosomes and/or their parts, involved into recombination processes.
对总共40个普通小麦（2n = 42）渐渗系进行了研究，这些渐渗系是由普通小麦（Triticum aestivum L）与提莫菲维小麦（T. timopheevii Zhuk.）杂交获得，对条锈病具有抗性，对白粉病有部分抗性。基于花粉母细胞（PMC）减数分裂的细胞学分析，将杂种系分为两组，其特征分别为减数分裂稳定或不稳定。在细胞学稳定的品系中，减数分裂中期I（MI）阶段的染色体构型大多为二价体（21II），缺陷细胞比例较小（近10%），这些缺陷细胞最多含有两个单价体（20II + 2I）。细胞学不稳定组由减数分裂PMC中染色体配对异常细胞比例高、含有多价体的品系以及含有非整倍体植株的品系组成。利用SSR标记对提莫菲维小麦片段进行定位，结果表明，与稳定品系相比，减数分裂不稳定的品系具有更多的渐渗片段。还证明了提莫菲维小麦的某些染色体对染色体配对稳定性的影响。在细胞学不稳定的品系中，观察到2A替换频率增加，同时提莫菲维小麦遗传物质向7A染色体渐渗的频率也很高。在7A染色体的所有渐渗情况下都观察到了多价体。有人认为，杂种形式基因组不稳定的原因在于参与重组过程的某些提莫菲维小麦染色体和/或其部分的补偿能力不足。
