中国大豆育成品种10个重要家族的遗传相似性和特异性

Genetic Similarity and Specificity of Ten Important Soybean Cultivar Families Released in China

以我国10个大豆育成品种重要家族的179个品种为材料，选用161个均匀分布于大豆基因组的SSR分子标记，采用PowerMarker Ver．3．25软件分析参试材料的遗传多样性、相似性与特异性。结果表明，161个位点上共检测到1697个等位变异，单位点变幅为5～24个，平均10．5个；多态信息含量在0．549～0．937间，平均0．819；群体具有丰富的遗传变异。聚类分析表明，179个品种可归为6大类11小类，同一家族的品种有聚为一类的趋势。品种间亲本系数和遗传相似系数显著相关（r=0．67）；山东寿张县无名地方品种（A295）、即墨油豆（A133）、滑县大绿豆（A122）和铜山天鹅蛋（A231）4个家族亲本系数和相似系数均较小，遗传基础较宽广；矮脚早（A291）、上海六月白（A201）、奉贤穗稻黄（A084）和51—83（A002）4个家族亲本系数和相似系数较大，遗传基础较狭窄，这与选择育种品种较多有关；东北白眉（A019）家族与其他家族间的亲本系数和遗传相似系数均最小。家族间特异性分析表明，东北白眉（A019）家族和其他9个家族地理距离较远，存在较多互补、特有、特缺等位变异；而III区和II区地理位置较近，种质交流较多，两区家族间特有、特缺等位点数较少，其中A002、A231和A122三个家族无特有等位变异，A084、A201、A034和A231四个家族无特缺等位变异。本研究结果对拓宽大豆育成品种遗传基础具有指导意义。

Analysis of the affinity relationship and genetic similarity among cultivars is important for crop genetic improvement. In this study, a total of 161 SSRs covering the entire soybean genome were analyzed for the genetic diversity, similarity and specificity of 10 important families composed of 179 cultivars using PowerMarker Ver. 3.25. The results showed that there were totally 1697 alleles, averaging 10.5 per locus, ranging from 5 to 24 with average polymorphism information content of 0.832, ranging from 0.545 to 0.943 in the population. According to the SSR cluster analysis, the 179 cultivars were clustered into six groups, eleven subgroups, with a tendency that the cultivars in a family tended to be grouped into a same cluster. There existed significant correlation （r = 0.67） between coefficient of parentage （CP） and genetic similarity coefficient （GSC） of the population. The CP and GSC values of A295, A133, A122, and A231 families were relatively low, which means that the genetic bases of the four families were relatively broad. In contrast, the CP and GSC values of A291, A201, A084, and A002 families were relatively high, indicating their genetic bases were relatively narrow due to more cultivars obtained from pure line selection. The CP and GSC values between the A019 family from Northeast China and other nine families were the lowest among all pairwise combinations of families. The genetic specificity analysis showed that there existed much more complementary alleles, specifically existent and specifically deficient alleles in A019 in comparison with in other families, indicating the former is distant from the latter. On the other hand, the families in Eco-region II and III, contained fewer complementary alleles, specifically existent and specifically deficient alleles, which might be due to some frequent germplasm exchange between the neighboring eco-regions. For example, there were no specifically existent alleles in A002, A231, A122 and no specifically deficient alleles in A084, A201, A034, and A231. The present results are of significance in broadening the genetic basis of soybean cultivar.