中国大豆(Glycine max)核心种质构建Ⅰ.取样方法研究

Establishment of Chinese Soybean (G.max) Core Collection Ⅰ. Sampling Strategy

以 2 3 587份中国栽培大豆为试验材料 ,根据农艺性状 ,用 2 0种方法构建了大豆初级核心种质 ,对 3种分层法、3种确定取样数法和 2种个体选择法进行了比较 ,明确了栽培大豆核心种质构建的适宜取样方法和取样比例。不同取样方法与总体都进行了品种分类数、各性状符合度、数量性状平均数、各性状多样性指数方差和平均品种距离共 5个指标的比较分析 ,结果表明 ,三层次取样方法 (品种分类法 )对总体的代表性优于二层次或一层次取样法 ,按比例和平方根确定取样数方法对总体的代表性优于多样性指数法 ,聚类选择的方法对总体的代表性优于随机选择方法。在 2 0种方法不同取样比例条件下 ,方法 17的平均品种距离降低幅度大于方法 15。因此 ,利用品种分类法进行分层 ,用比例法确定取样数目 ,根据聚类结果进行个体选择的方法 15是构建大豆初级核心种质的最佳方法。用最佳方法构建的初级核心种质 ,比较不同取样比例的品种平均距离 ,确定品种平均距离由缓慢降低到明显降低点 (9.0 % )

In this paper, 23 587 cultivated soybeans were analyz ed by using agronomic characteristics in order to find out optimal sampling strate gy and sample size for developing soybean core collection in China. The 20 sampl ing strategies were used, 18 of them consisted of 3 stratifications, 3 determina tions of sampling number and 2 selections of individuals methods, and the rest 2 were checks. The criteria against whole collection include variety classificat ion, coincidence of 14 characters, mean of 5 quantitative characters, variance o f genetic diversity, mean of variety distance. The results indicated that variet y classification was better than methods of one or two stratifications, the pro portional sample determination was better than methods of square root or geneti c diversity, and clustering selection of sample was better than random selection . Therefore, method 15 would be optimal strategy for developing primary Chinese soybean core collection. By using this method, various samples with different p roportions of whole collection were compared for mean variety distance, and the sample size of 9% were taken as the best proportion for construction primary cor e collection because it could keep the variation with the least varieties.