南瓜栽培品种的SSR分子标记分析及农艺性状多样性研究

为了研究南瓜栽培品种的遗传多样性,本研究利用43个简单序列重复(SSR)分子标记,对35份南瓜育成品种及地方品种进行了分子标记分析,并调查了农艺性状。结果表明,43个SSR标记均能扩增出多态性条带,共检测到155个等位基因,平均每个标记能检测到3.6个等位基因,多态性信息含量(PIC)为0.130 8~0.775 4,平均值为0.487 2。利用非加权组平均法(UPGMA)进行聚类分析,结果表明35份材料可分为三大类,分别与中国南瓜、印度南瓜和美洲南瓜三个种吻合,且印度南瓜与美洲南瓜之间的亲缘关系较近。农艺性状调查结果表明,不同栽培种之间以及同一栽培种内的不同品种之间,都发现有农艺性状差别明显的情况。本研究为南瓜种质资源的保护、品种指纹图谱的建立及分子育种提供了理论依据。

Analyses of Genetic Diversity by SSR Molecular Markers and Agronomic Traits Diversity in Squash and Pumpkin

In order to study the genetic diversity of squash and pumpkin (Cucurbita) cultivars and landrace, molecular marker analysis of 35 accessions were investigated with 43 simple sequence repetition (SSR) markers. The agronomic traits were also investigated. The results showed that all the SSR markers can produce polymorphic bands among 35 accessions. A total of 155 alleles were detected with an average of 4.1 alleles for individual marker. The polymorphism information content (PIC) was ranged from 0.130 8 to 0.775 4 with an average value of 0.487 2. The cluster analysis of 35 accessions by the unweighted pair group average method with arithmetic mean (UPGMA) indicated that all the accessions could be divided into three categories, corresponding to the American squash (C. pepo L.), Chinese pumpkin (C. moschato Duch) and Indian squash (C. maxima Duch), of which the Indian squash had a closer genetic relatedness to the American squash. Analysis of the agronomic characters of different accessions indicated that dramatic diversity in the agronomic traits was found not only among different species but also among different cultivars of the same species. This study provided a reference for further study on the genetic structure, fingerprinting construction, and molecular breeding of cucurbita cultivars.