广西生产上主要应用的三系杂交稻不育系遗传多样性分析

Genetic diversity analysis of male sterile lines for three-line hybrid rice mainly applied in Guangxi

【目的】分析三系杂交稻不育系的遗传多样性和亲缘关系,为广西杂交水稻不育系的创新和选育奠定基础。【方法】选取均匀分布于水稻12条染色体上的34对SSR引物,对25份广西生产上主要应用的三系杂交稻不育系进行遗传多样性分析和聚类分析。【结果】34对引物在25份不育系材料中共检测到112个等位基因,每对引物检测到的等位基因数为2-7个,平均为3.2941个;有效等位基因数为1.0832-5.8411,平均为2.3170个,Nei’s基因多样性指数为0.0768-0.8288,平均为0.4922;多态信息含量（PIC）为0.0739-0.8067,平均为0.4381,属于中度多态位点;遗传相似系数为0.5565-0.8870,平均为0.6936。聚类分析结果表明,在遗传相似系数为0.6400处可将25份不育系材料分成两大类,桂丰A和桂19A聚为第一大类,其他23份材料聚为第二大类,且第二大类在遗传相似系数0.7200处又可以分成四个亚类。【结论】广西生产上主要应用的三系杂交稻不育系的遗传变异程度中等,遗传多样性不高,亲缘关系较近,遗传背景较单一。

[Objective]The present research was conducted to analyze the genetic diversity and relationship of male sterile lines for three-line hybrid rice mainly applied in Guangxi in order to lay the foundation for innovation and breeding of new male sterile lines in Guangxi. [Method]A total of 25 male sterile lines for major three-line hybrid rice applied in Guangxi were investigated the genetic diversity and cluster by using 34 pairs of SSR primers distributed on 12 chromosomes of rice. [Result]A total of 112 alleles were identified in 25 materials by using 34 pairs primers, the average allele was 3.2941 per SSR locus with a range from 2 to 7. The average effective allele per SSR locus was 2.3170 with a range from 1.0832 to 5.8411. The average of Nei＇s gene diversity was 0.4922 with a range from 0.0768 to 0.8288. The allelie polymorphism information content （PIC） ranged from 0.0739 to 0.8067, on an average of 0.4381 per SSR maker. The average genetic similarity coefficient was 0.6936 with a range from 0.5565 to 0.8870. UPGMA cluster analysis results showed that, the 25 cultivars could be classified into 2 groups at similarity coefficient of 0.6400, the first only included Guifeng A and Gui 19A, the second was the another 23 male sterile lines, which could be classified into 4 subgroups at similarity coefficient of 0.7200. [Conclusion]The main male sterile lines of three-line hybrid rice applied in Guangxi showed moderate genetic variability lower genetic diversity, similar ancestry and single genetic background.