小豆SSR分子标记遗传连锁图谱构建

Construction of Genetic Linkage Map Using SSR Molecular Markers in Azuki Bean(Vigna angularis Ohwi and Ohashi)

【目的】以小豆SSR为锚定标记,将公开发表的豇豆SSR、普通菜豆SSR和EST-SSR标记定位整合到小豆遗传连锁群中,构建中国小豆遗传图谱,为小豆基因定位、图位克隆和分子标记辅助选择育种提供更多可用的分子标记。【方法】用1 473对SSR和EST-SSR引物进行PCR扩增,包括906对豇豆SSR、123对普通菜豆和196对小豆SSR引物及248对普通菜豆EST-SSR引物,筛选亲本间多态性标记,验证栽培小豆HB801×AG109及GM892×AG110的F2分离群体。【结果】整合和构建了含有145个SSR和EST-SSR标记小豆遗传连锁图谱,包括59个小豆SSR标记,新增63个豇豆SSR、9个普通菜豆SSR、14个普通菜豆EST-SSR标记和1个茎色标记。紫茎色性状被定位在第9连锁群,离CEDG022和cbess058标记的遗传距离分别为0.9 cM和0.1 cM。图谱全长823 cM,覆盖11个连锁群,每个标记间平均距离为5.64 cM。每个连锁群长度为49.1—125.6 cM,平均长度74.82 cM;每条染色体上的标记数7—26个,平均13.27个。【结论】率先把小豆近缘物种分子标记引入小豆,加密了小豆SSR分子标记遗传连锁图谱。

[Objective] The published SSR primers of cowpea, common bean and EST-SSR （expressed sequence tags） primers of common bean were located and integrated in azuki bean linkage group to construct a linkage map of Chinese azuki bean with azuki bean SSR primers as anchor markers. More practical molecular markers will be supplied to gene mapping, cloning and molecular marker-assisted selection of azuki bean. [ Method] A total of 1 473 SSR and EST-SSR primer pairs, including 906 SSR primer pairs of cowpea, 123 SSR and 248 EST-SSR of common bean, 196 SSR primer pairs of azuki bean, were used for PCR amplification to screen polymorphic markers between cultivated azuki bean parents of HB801 xAG109 and GM892xAG110. Their F2 segregating populations were tested with the polymorphic markers. [ Result ] An integrated genetic linkage map of azuki bean containing 145 SSR and EST-SSR markers was constructed. This molecular genetic linkage map is composed of 59 azuki bean SSR anchoring markers, newly mapped 63 cowpea SSR markers, 9 common bean SSR markers and 14 common bean EST-SSR markers, as well as a stem colour marker-the purple stem trait which is located on linkage group 9. Genetic distance of purple stem trait from CEDG022 and cbess058 molecular markers is 0.9 cM and 0.1 cM, respectively. The total length of the linkage map was 823 cM and covered 11 linkage groups. The average distance between markers was 5.64 cM. The average distance of each linkage group spanned 74.82 cM. The average number of markers was 13.27 for each of 11 chromosomes. The length of each linkage group ranged from 7to 26 markers was from 49.1 cM to 125.6 cM. [Conclusion] Molecular markers of the relative species were freshly introduced in azuki bean and increased density of its genetic linkage map. It is useful for gene mapping and cloning, molecular marker-assisted selection in azuki bean.