应用SSR分子标记分析小麦品种(系)的遗传重组

Genetic Recombination in Wheat Using SSR Markers

为了解小麦品种形成中亲本基因组的遗传重组和遗传保留区段的分布特点，对周麦18和百农AK58及其衍生品系共23个材料进行了全基因组SSR扫描分析。遗传重组分析表明，单交组合的平均重组数（12.3）低于回交组合（13.9）；染色体4A、5A、7A、1B、3B、4B、7B、1D、2D、3D、5D、6D和7D重组发生较多，其余染色体重组相对较少，染色体的中间区段与远端区段重组数相当，分别为6.1和6.0。子代间基因组比较发现，一些染色体区段成为重组的多发区，如5D的gwm358–wmc357、6D的cfd49–barc196、7A的wmc158–barc23和7B的gwm274–gwm146区段，分别有35、19、15和14次重组。分析亲本传递给子代的染色体区段，发现子代继承亲本的遗传区段在14~29个，每个区段涉及2~8个多态性位点，大的遗传区段主要分布于4A、5A、5B、5D和7D染色体。以上基因组区域的关联性状是进一步研究的重点。

To understand the characteristics of inheritance and recombination of parental chromosome fragments in wheat progenies, we screened the genomes of 23 genotypes derived from Zhoumai 18 and Bainong AK58 with 340 SSR markers covering the whole wheat genome, together with the parents. The average recombination frequency in cultivars from single-cross was 12.3, which was smaller than that in cultivars from single backcross （13.9）. Recombination mostly occurred on chromosomes 4A, 5A, 7A, 1B, 3B, 4B, 7B, 1D, 2D, 3D, 5D, 6D, and 7D. The distal and central chromosomal regions had similar frequencies of recombination which were 6.1, and 6.0, respectively. Some chromosomal regions were hot in recombination, such as marker intervals gwm358–wmc357 on chromosome 5D, cfd49–barc196 on chromosome 6D, wmc158–barc23 on chromosome 7A, and gwm274–gwm146 on chromosome 7B, with 35, 19, 15, and 14 recombination events, respectively. The analysis for inheritance of large linkage blocks indicated that large chromosome fragments inherited from one parent varied from 14 to 29 in each derivative, with 2–8 consecutive and informative SSR loci in a fragment. These large fragments were mainly distributed on chromosomes 4A, 5A, 5B, 5D, and 7D, which might harbor genes controlling important agronomic traits.