北京地区野生大豆种群SSR标记的遗传多样性评价

 使用40对SSR引物分析了北京地区野生大豆(Glycine soja)天然种群的遗传结构与遗传多样性。10个种群共检测到526个等位变异, 平均每对引物等位基因数为13.15个, 种群平均Shannon指数(I)为0.658, 群体平均位点预期杂合度(H_e)为0.369, 群体平均位点杂合度(H_o)为1.29 %。平均种群内遗传多样度(H_s)为0.362, 平均种群间遗传多样度(D_ST)为0.446, 基因分化程度(G_ST)为0.544。该研究显示, 中-西部生态区种群比北部和东部山区种群有较高的遗传多样性。在地理上, 环绕北京地区的太行山和燕山两大余脉区域野生大豆种群遗传分化表现出地理差异。可能是经过干旱选择而形成的有抗旱潜力的种群在遗传上表现单一化。期待该种群提供耐旱基因。

EVALUATION OF GENETIC DIVERSITY BY SSR MARKERS FOR NATURAL POPULATIONS OF WILD SOYBEAN (GLYCINE SOJA) GROWING IN THE REGION OF BEIJING, CHINA

Aims Wild soybean (Glycine soja) is commonly accepted as the progenitor species of the cultivated soybean (Giycine max). It contains many characters potentially valuable for supplementing the soybean germplasm pool, yet little research has been done on genetic diversity in natural populations of wild soybean in China. Our objective was to evaluate genetic diversity in natural populations of wild soybean growing in the region of Beijing, China. Methods We sampled ten representative natural populations in 2005. Every sampled population consisted of 28-30 individuals and was over 10 m apart. Forty public SSR primer pairs over the 20 linkage groups were applied to evaluate genetic diversity. Important findings A total of 526 alleles (bands) were detected with an average number of 13.15 per locus. Mean expected heterozygosity per locus (H_e) was 0.369 for the populations, and the mean Shannon index (I) for the populations was 0.658. Mean observed heterozygosity per locus (H_o) for the populations was 1.29%. Between-population genetic diversity (H_s) averaged 0.446, and within-population genetic diversity (D_ST) averaged 0.362. Mean coefficient of gene differentiation for loci (G_ST) in the populations was estimated to be 0.544. This study showed that the center-western ecotype had higher genetic diversity than the northern and eastern ecotypes and that there appeared to be ecogeographically genetic divergence in the natural populations between the Taihang and the Yanshan mountains. A strongly drought-tolerant population had very low genetic diversity, and its tolerance gene(s) may be exploited for breeding.