整合质量数量性状构建作物核心种质的策略研究

质量性状和数量性状在不同水平反映了个体间的遗传差异,现有遗传相似性的度量往往割裂两者的信息.本文提出了整合质量性状和数量性状评价个体间遗传相似性的统计策略,调整的欧氏距离能有效地度量个体间的差异,并能很好地处理性状数据的缺失.实例分析了中国农业科学院、华南农学院、广东省农科院水稻生态研究室收集和调查的2262份水稻种质资源10个质量性状和15个数量性状的数据资料,用调整的欧氏距离及不加权类平均法进行群体分类,多次聚类优先取样法抽取8个不同容量的巢式子集并进行遗传多样性比较.结果表明:基于整合信息构建的核心种质同时具有较高的数量性状和质量性状遗传多样性;仅用质量性状信息不足以评价个体间的遗传差异;核心种质构建中应该采用数量性状的信息,同时整合质量性状的信息.

Study on the strategies of integrating qualitative and quantitative traits for constructing core collection

Genetic differences between accessions can be reflected by qualitative and quantitative traits at diverse levels. Currently, qualitative traits and quantitative traits are independently utilized in measuring genetic similarity between individuals. A strategy of integrating qualitative traits and quantitative traits was proposed for establishing a core collection of germplasm; adjusted Euclidean distance was found effective in detecting genetic differences between accessions, which is also flexible in dealing with missing data. A case study was conducted on 10 qualitative and 15 quantitative traits of 2262 rice accessions collected and investigated by the Rice Ecology Research Lab of the Chinese Academy of Agricultural Sciences, the South China Agricultural College and the Guangdong Academy of Agricultural Sciences; adjusted Euclidean distance and the Unweighted Pair Group Method with Arithmetic mean (UPGMA) were used in classification of population; 8 nested core subsets were sampled by stepwise clustering with preferred sampling strategy, for evaluating the proposed method. The results showed that subsets based on integrated strategy harbored widen genetic diversity of qualitative and quantitative traits; qualitative traits are not effective enough in measuring genetic differences between accessions; constructing of core collection should be based on quantitative traits associated with integration of qualitative information, if possible.