基于不同策略构建辣椒核心种质的研究

Construction of Chili Pepper Core Germplasms Based on Different Strategies

核心种质的构建为作物种质资源的高效利用提供了便利条件。以420份辣椒(Capsicum annuum L.)种质为试材,采用混合线性模型分析方法无偏地预测11个数量性状的基因型值,利用马氏距离计算种质间的遗传距离,分别采用3种聚类方法(中间距离法、类平均法和离差平方和法)、3种抽样方法(随机抽样法、优先抽样法和偏离度抽样法),按照25%的抽样比率构建辣椒核心种质库,采用均值、方差、极差和变异系数4个指标评价不同方法构建核心种质库的优劣。结果表明,类平均法优于中间距离法和离差平方和法,偏离度抽样法优于随机抽样法和优先抽样法。基于马氏距离、类平均法、偏离度抽样法获取的105份辣椒核心种质资源能够代表原群体的遗传多样性,为辣椒种质资源的高效利用提供了重要的理论依据。

The construction of crop core germplasms could facilitate the effective utilization of genetic resources. Taking 420 chili pepper（Capsicum annuum L.） germplasms as materials,the genotypic value of 11 quantitative traits was predicted according to mixed linear model analysis method. The genetic distance among germplasms was calculated using Mahalanobis distance based on genotypic value. Core germplasms were constructed by 3 cluster methods（median,UPGMA and ward＇s method） and3 sampling strategies（random sampling, preferred sampling and deviation sampling） with 25% sampling ratio. The genetic variation between core germplasms and initial germplasms was compared through evaluating the mean, variance, range and coefficient of variation. The results showed that UPGMA was better than median and ward＇s method; while deviation sampling was better than preferred sampling and random sampling. 105 core germplasms obtained based on Mahalanobis distance, UPGMA and deviation sampling, could represent the genetic diversity of initial germplasms adequately. This study could provide important theoretical basis for efficient utilization of chili pepper germplasms.