275份辣椒种质资源表型性状的遗传多样性分析

Genetic diversity analysis of phenotypic characters in 275 pepper germplasm resources

为了挖掘能够应用于遗传改良的种质资源,并筛选出优良表现的核心种质资源,为辣椒品种改良创新提供理论依据,以275份辣椒为研究材料,对42个表型性状进行遗传多样性分析、相关性分析、主成分分析以及聚类分析。结果表明:15个数量性状的Shannon-Wiener多样性指数(H')的变化范围为1.90~2.26,其中叶片长的H'值最高为2.26,其变异系数(coefficient of variation,CV)的变化范围为22.38%~146.09%。以辣椒素含量的变异系数最高为146.09%,变异幅度为48~290231SHU。27个质量性状的Shannon-Wiener多样性指数(H')的变化范围为0.03~2.81,其中果形有13种分布类型,其频率分布范围为1.87%~31.84%,大多数为灯笼形与羊角形,其遗传多样性指数也是最高为2.81,表明275份辣椒种质的表型性状具有丰富的遗传多样性。相关性分析结果表明,各表型性状间的相关系数中达到显著或极显著的有189对性状,这表明许多表型性状间相互影响。主成分分析结果表明,前13个主成分累加贡献率为68.62%,代表了辣椒表型性状的主要信息量,说明这13个主成分可反映42个表型性状的基本特征,从特征值和贡献率来看,果横径、单果重、果形、果肩形状、胎座大小,叶片长、叶片宽、叶柄长、株幅、分枝性、茎茸毛、叶面茸毛、花冠色、花药颜色、花柱颜色和果色共17个表型性状是引起辣椒种质表型不同的主要因素。聚类分析结果表明,在遗传距离为40.0时,275份辣椒种质可聚为5个类群。该研究为辣椒种质资源的利用、创新及品种选育提供了重要参考。

In order to explore germplasm resources that can be applied to genetic improvement and screen core germplasm resources with excellent performance,providing a theoretical basis for innovation in pepper variety improvement,in this study,275 pepper samples were used to conduct genetic diversity analysis,corre-lation analysis,principal component analysis and cluster analysis on 42 phenotypic traits.The results showed that the Shannon Wiener diversity index(H´)of 15 quantitative traits varied from 1.90-2.26,among which the highest H´value of leaf length was 2.26,and the variation range of coefficient of variation(CV)was from 22.38%to 146.09%.The highest coefficient of variation of capsaicin content was 146.09%,and the range of variation was 48-290231 SHU.The Shannon Wiener diversity index(H´)of 27 quality traits varied from 0.03 to 2.8,of which,there were 13 distribution types of fruit shape,and the frequency distribution ranged from 1.87%to 31.84%.Most of them were of lantern shaped and sheep horn shaped,and the highest genetic diversity index was 2.81,indicating that 275 pepper germplasms have rich genetic diversity in phenotypic traits.Correlation analysis showed that 189 pairs of phenotypic traits had significant or extremely significant correlation coefficients among the phenotypic traits,indicating that most of the phenotypic traits affect each other.The results of principal component analysis showed that the cumulative contribution rate of the first 13 principal components was 68.62%,representing the main information content of pepper phenotypic traits,indicating that the 13 principal components can reflect the basic characteristics of 42 phenotypic traits.From the characteristic values and the contribution rates,fruit transverse diameter,single fruit weight,fruit shape,fruit shoulder shape,placental size,leaf length,leaf width,petiole length,plant width,branching,stem fuzz,leaf surface fuzz,corolla color,anther color style color,green ripe fruit color and old ripe fruit color were 17 phenotypic characters,which were the main factors causing phenotypic differences in pepper germplasm.Cluster analysis showed that 275 pepper germplasms could be grouped into five groups when the genetic distance was 40.0.This study provides an important reference for the utilization,innovation and variety breeding of pepper germplasm resources.