广西地方玉米种质和加拿大群体的遗传多样性分析

 【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。

Genetic Diversity Among Guangxi Local Maize Varieties and Canadian Maize Populations

Abstract： In order to take the best of the Guangxi local maize varieties and broaden the genetic base of the Guangxi maize germplasm, the genetic diversity among 45 Guangxi local maize varieties (OPVs) and 15 Canadian maize populations, was analyzed used Bulk-SSR method. The total 240 DNA samples were extracted from 4 bulks of DNA for each population or OPV, and 10 random individual plants equally for each bulk. The results showed that 245 alleles were detected with 70 pairs of selected primers in the 240 bulks of DNA samples attracted from 60 OPVs or populations. The number of alleles per locus was on average 3.5 and ranged 2-6. The Clustering results with UPGMA method based on the genetic similarities of 60 populations showed that 45 Guangxi local OPVs and 15 Canadian populations were classified into 2 groups. Each group consisted of flint and dent subgroups. The waxy corn samples from Guangxi were not clustered as an independent group, but into flint or dent subgroups. Seven levels of allelic combinations among 245 were designed to analyze the least number of alleles required to reveal genetic relationship among the 60 populations. The results indicated that 160 alleles were enough to cluster the 60 germplasm in the current study. Diagnostic alleles were amplified with some certain primers in Guangxi and Canadian germplasm, respectively. Combined with the results of clustering analysis, these diagnostic alleles will be of great importance to find the useful maize germplasm in breeding efforts.