我国三系杂交稻主要不育系的微卫星标记多样性和遗传结构分析

SSR Diversity and Genetic Structure of Main Male Sterile Lines of Three-Line Hybrid Rice in China

选取均匀分布在水稻12条染色体上的48对SSR引物，对28份我国杂交水稻主要不育系进行了多样性和遗传结构分析。在所分析的48个位点中，多态性位点41个，多态性位点百分率（P）为85．4％；每1个位点平均等位基因数（A）为3．5，变幅2～6个；平均基因多样性指数（HP）和平均多态性信息含量指数（PIC）分别为0．40和0．36。AMOVA分析表明，不育系遗传变异主要存在于各选育时期内，时期间的遗传变异仅占总变异的3．3％，且未达到显著水平。基于模型的遗传结构分析表明，我国三系杂交稻主要不育系多数含有相近血缘，背景单一。

A total of 28 male sterile lines for major three-line hybrid rice in China were investigated by SSR assay with 48 pair primers distributed on 12 chromosomes of rice. The results revealed that 41 loci were polymorphic, with a polymorphic rate of 85.4%. The number of alleles per locus （A） ranged from 2 to 6 with an average value of 3.5. Neits genetic diversity index （He） and the values of polymorphism information content （PIC） were 0.40 and 0.36, respectively. Analysis of molecular variance （AMOVA） showed that the genetic differentiation among the breediing periods was rather small （Fst = 0. 033） and not significant （P〉0.05）. However, the differentiation within the breeding periods was very high. Model-based analysis showed that it contained similar ancestry for main male sterile lines of three-line hybrid rice in China, implying that enriching genetic diversity in male sterile lines should be important in hybrid rice breeding program.