中国普通野生稻与栽培稻种SSR多样性的比较分析

采用48对SSR引物对288份我国普通野生稻和栽培稻的遗传多样性进行比较分析。结果显示, 共检测到505个等位基因, 每个位点的等位基因数变幅为5~20, 平均10.5个; 平均Nei基因多样性指数(He)为0.731, 变幅为0.384(RM409)~0.905(RM206)。普通野生稻遗传多样性高于栽培稻种, 栽培稻等位基因数和平均Nei基因多样性指数分别为普通野生稻的70.2%和88.2%, 其中, 栽培稻地方品种和选育品种等位基因数分别为普通野生稻的65.4%和53.0%, 选育品种等位基因数仅为地方品种的81.1%。AMOVA分析表明, 总变异的10.3%是由于种间SSR遗传差异所引起的, 不同SSR位点种间的分化程度不同, 在0.7%~46.3%之间, 有43个位点种间遗传分化达到显著水平, 其中以RM427分化最为明显, 达46.3%。聚类分析表明, 中国普通野生稻总体偏粳, 极少数广东、海南材料偏籼。

Comparative Assessment of SSR Allelic Diversity in Wild and Cultivated Rice in China

Forty-eight SSR markers were used to compare genetic diversity in 288 accessions of common wild rice (O. rufipogon Griff.) and cultivated rice (O. sativa L.) in China. There were 505 alleles at the 48 loci investigated. The average number of alleles per locus (Na) was 10.5 with a range from 5 to 20. Total Nei’s genetic diversity index of Nei per locus (He) varied widely from 0.384 (RM409) to 0.905 (RM206) with an average value of 0.731. By comparison of the genetic changes in Na and He, the genetic di-versity of common wild rice was obviously higher than that of cultivated rice. Na and He of cultivated rice was only about 70.2% and 88.2% of common wide rice, respectively. In cultivated rice, Na of landraces and improved varieties were 65.4% and 53.0% of common wild rice respectively, and Na of improved varieties was 81.1% of landraces. Analysis of molecular variance (AMOVA) indicated that 10.3% of the variation was from differences between species. Using locus-by-locus AMOVA procedure, there were 43 loci with significant differentiation. The highest genetic differentiation was 46.3% (RM427) with a range from 0.7% to 46.3%. A cluster analysis showed japonica was the main trend for most of common wild rice in China. In addition, only a few of accessions from Guangdong and Hainan showed tendency towards indica type.