论文部分内容阅读
以国家蔬菜种质资源中期库收集保存的1651份大白菜种质为试材,按照大白菜分类系统和生态型,采用分层分组法,将所有种质分为6组。基于43个形态性状的数据,比较了4种组内取样比例法、6种总体取样规模和2种取样方法在构建大白菜核心种质中的作用和效果。结果表明:组内以多样性比例法更能使各组的取样份数或比例趋于平衡,并较好地保持原始收集品的变异度。当总体取样规模为15%时,多样性比例法所构建的核心种质的遗传多样性指数达到最大,表型保留比例亦能达到98%左右;而当总体取样规模增加到20%以上时,虽然表型保留比例接近100%,但核心种质遗传多样性指数迅速降低。因此,认为15%总体取样规模较为合适。在一定的组内取样比例法和总体取样规模下,聚类取样构建的核心种质的遗传多样性指数(I)、表型保留比例(RPR)和变异系数(CV)均比随机取样的高。根据获得的优化方案最终在表型水平建立了包含248份种质的中国大白菜核心种质。
According to the classification system and ecological type of Chinese cabbage, 1651 Chinese cabbage germplasms collected from the National Medium-term Vegetable Germplasm Resources Bank were divided into 6 groups by stratified grouping method. Based on the data of 43 morphological traits, the effects of four sampling ratios, six sampling scales and two sampling methods on the construction of Chinese cabbage core collection were compared. The results showed that: within the group with the proportion of the proportion of the more able to make each sample the number of copies or ratio tends to balance, and better maintain the original collection of variability. When the overall sampling size was 15%, the genetic diversity index of the core collection constructed by the diversity ratio method reached the maximum, and the retention percentage of the phenotype reached about 98%. When the overall sample size increased to more than 20% Although the phenotypic retention rate was close to 100%, the core diversity index of germplasm rapidly decreased. Therefore, we think that 15% of the overall sample size is more appropriate. Cluster analysis showed that the genetic diversity index (I), the ratio of phenotypic retention (RPR) and the coefficient of variation (CV) of the core collection constructed by cluster sampling were higher than those of the random sample under the sampling ratio method and the overall sampling scale . Based on the optimized scheme, 248 core collections of Chinese cabbage were finally established at the phenotypic level.