基于SSR标记不同距离聚类与抽样方法构建辣椒核心种质库

Construction of Core Capsicum Germplasm Bank Based on Different Distance Clustering and Sampling Method of SSR Marker

为最大限度地保存辣椒原群体的遗传变异度,利用SSR分子标记技术比较不同距离聚类和抽样方法构建辣椒的核心种质库。结果表明:在马氏距离下,4种抽样比例中当抽样比例达20%和25%时均值差异百分率MD%为0;在相同欧氏距离下,4种抽样比例中,以10%、15%和20%比例进行抽样均值差异百分率(MD%)为0。在采用的8种聚类方法中,只有最短距离法均值差异百分率(MD%)为最小值0。不同取样法,变异系数变化率为多次聚类偏离度取样法(107.06%)>多次聚类随机取样法(101.18%)>多次聚类优先取样法(59.57%)。从97份参试材料中筛选出沿河2、德江5、石阡3、台江1、仁怀4、务川2、遵义5、河南1和海南1共计9份核心种质,均匀分布于不同的类群中。结论:在欧氏距离下,按10%比例进行抽样,用多次聚类随机取样法取样、最短遗传距离法进行聚类分析为构建辣椒核心种质库的最佳选择。

Difference between core capsicum germplasm banks established by different distance clustering and sampling methods respectively was compared by SSR marker technology to preserve genetic variation degree of capsicum original populations farthest. MD %（ mean difference） of 20 % and 25 % sampling treatments is 0 under mahalanobis and MD % of 10 %,15 % and 20 % sampling treatments is 0 under the same Euclidean distance. MD % of the minimum distance method in used 8 clustering methods is the minimum（ 0）. Variation rate of variable coefficient（ VR） of different sampling methods is multiple cluster deviation method（ 107. 06 %）〉 multiple cluster random sampling method（ 101. 18 %） 〉multiple cluster priority sampling method（ 59. 57 %）. 9 core germplasms（ Yanhe,Dejiang,Shiqian,Taijiang,Renhui,Wuchuan,Zunyi,Henan and Hainan） selected from 97 tested varieties. are distributed in different groups uniformly. In conclusion,the optimum selection for construction of core capsicum germplasm bank includes 10 % sampling ratio under Euclidean distance,multiple cluster random sampling method and the minimum genetic distance method.