国外种质对中国大豆育成品种遗传贡献的分子证据

用SSR标记对32份中国大豆品种与40份国外引进大豆育成品种祖先亲本的遗传多样性进行分析，以明确引进国外大豆种质对中国大豆育种的遗传贡献。结果表明，在22个SSR位点共检测到170个等位变异，中国大豆和引进国外大豆平均等位变异数分别为6.0和6.9个，遗传多样性指数都为0.71，国外品种中检测到48个特有等位变异，而中国大豆中仅检测到22个，且共有等位变异在中外大豆中的分布频率差异较大。聚类分析也发现中国育成品种与国外引进大豆存在较大差异。遗传组成分析发现，Amsoy和十胜长叶2个国外种质的引入使5个中国大豆育成品种增加了23个国外种质特有等位变异；其在育成品种中的保留比例为29.13%，但不同遗传背景中保留的等位变异不同，说明国外种质在中国大豆育种中起着重要作用，而且仍有很多特有等位变异没有被利用，可以继续作为亲本在中国大豆改良中发挥作用。

Marker-Based Evidence of Broadening the Genetic Base of Chinese Soybeans by Using Introduced Soybeans

Molecular marker analysis can be used to quantify diversity of Chinese and introduced soybean germplasm and can provide useful information for the relationship of these materials.The genetic diversity of 32 Chinese varieties and 40 foreign ancestral cultivars were investigated by 22 SSR markers.One hundred and seventy alleles were detected,with an average of 6.0 and 6.9 in Chinese and foreign materials,respectively.The polymorphism information content(PIC) was 0.71 in both populations,which indicated a relatively high genetic diversity.There were 48 specific alleles in foreign materials and only 22 in Chinese varieties.The frequency of the alleles in common was very different in the two populations.Great differentiation was also observed between the two populations when UPGMA cluster analysis was used.We analyzed the pedigree of five Chinese cultivars derived from two introduced soybean cultivars,Amsoy and Tokachi nagaha,and found 23 specific alleles from foreign materials.The reserved specific alleles were different in each genetic background,and 29.13% specific alleles were reserved in total.This indicated that the introduction of foreign materials in Chinese soybean breeding increased the soybean genetic diversity.For foreign materials,more specific alleles have not been used yet,and should be used as parental materials in elite lines breeding in the future to enlarge the genetic bases of Chinese soybean.