用EST-SSRs研究小麦遗传多样性

Study on the Genetic Diversity of Wheat by EST-SSRs

小麦EST-SSRs是从小麦ESTs序列(表达序列标签)中开发的一种新型SSR标记。研究采用35对小麦EST-SSRs标记检测了 96份小麦材料的遗传多样性。结果表明,这些小麦EST-SSRs引物均可获得清晰的预期产物,共检测到129个等位变异,其中87.6%有多态性,大多数引物有2～4个等位变异;其中部分引物可用于普通小麦及其近缘种属的亲缘关系研究,并可根据特征带谱鉴定部分小麦品种;在相似系数为0.745的水平可将人工合成双二倍体小麦材料和一般小麦品种区分开来。与基因组SSR标记相比,EST-SSRs这种新型分子标记来源于表达基因,将其用于小麦遗传研究可直接反映相关基因在不同小麦品种间的表达差异。

EST-SSR marker is a new kind of SSR markers which is developed from the ESTs (expressed sequence tags). In this study, a total of 35 EST-SSR markers were used to analyze the genetic diversity and phylogeny of 96 wheat germplasms. All the primer sets produced clear and strong expected amplifications. 129 alleles were generated by the 35 loci, but most of the primer pairs produced 2 to 4 alleles. 87.6% of the 129 alleles showed polymorphic among the 96 wheat varieties. Primer pairs could be used to identify some varieties according to the specific PCR amplifications, to reveal the phylogeny between hexaploid wheat collections and their ancestral chromosome donors. Based on 0.745 similarity coefficient, synthesized double diploid varieties and hexaploid wheat were classified into different subgroups. Compared with SSR markers derived from genomic DNAs, EST-SSRs were parts of expressed genes. Therefore, when used in wheat genetic analysis, EST-SSR markers not only act as genetic markers, but also reveal differences in related gene expression.