广西地方玉米种质和加拿大群体的遗传多样性分析

Genetic Diversity Among Guangxi Local Maize Varieties and Canadian Maize Populations

【目的】分析45份广西地方玉米品种和15份加拿大改良群体的遗传多样性,为更好地利用地方品种拓宽广西玉米种质的遗传基础提供理论依据。【方法】采用混合取样法(每个群体中随机提取4个混合样本,每个样本包括10个单株)和SSR分子标记技术进行研究。【结果】70对SSR引物在60个群体的240份样本中扩增出245条等位基因,每对引物检测出的等位基因数目为2～6条,平均每个位点3.5条。加拿大的15份群体和广西的45份地方品种分别聚为二大类群。加拿大的15份群体又可以分为硬粒型和马齿型两个亚群。在45份广西地方种质中,同样可以分为硬粒型和马齿型两个亚群;糯玉米没有单独聚类,而是分散在硬粒型类群当中。【结论】广西亚热带种质比温带的加拿大种质具有更大的遗传变异,研究这些材料的遗传多样性可更好地扩增广西玉米种质的遗传基础,对玉米育种中发现潜在突破性种质可能会起到一定的作用。

【Objective】 In order to use local varieties and exotics to broaden the genetic base of Guangxi improved maize germplasm, the genetic diversity among 45 Guangxi local maize varieties （OPVs） and 15 Canadian maize populations were analyzed. 【Method】The bulked-SSR strategy was adopted in this study. A total of 240 DNA samples were extracted, which consisted of 4 bulks of DNA from 10 individual plants per bulk to represent each population or OPV （using equal amounts of DNA per plant）. 【Result】The results showed that 245 alleles were detected with 70 pairs of selected primers in the 240 bulks from the 60 OPVs or populations. The number of alleles per locus averaged 3.5 and ranged 2-6. The clustering results using the UPGMA method based on the genetic similarities between each pair of populations showed that the 45 Guangxi local OPVs and the 15 Canadian populations were classified into 2 groups, respectively. Each group consisted of both flint and dent subgroups. The waxy maize samples from Guangxi were not clustered as an independent group, but dispersed in the flint group. 【Conclusion】The variation of Guangxi subtropical maize is higher than that of Canadian maize germplasm. The genetic base of Guangxi improved maize germplasm can be broadened with the Guangxi local varieties using the clustering results and diagnostic alleles, which will be of great importance to find useful germplasm in maize breeding efforts.