辣椒属5个栽培种部分种质亲缘关系的RAPD分析

 采用31个10 bp随机RAPD引物对辣椒属(Capsicum ) 5个栽培种31份材料进行PCR扩增,共扩增出276条带, 其中多态性带244条, 占88.41%。C. annuum 多态性位点比例( PPB) 和Shannon多样性指数( I) 分别为32.97%和0.1599, 表明其遗传多态性较低。31份材料两两不同种质间Jaccard相似系数在0.349～0.952之间, 平均为0.729。聚类分析结果显示: C. annuum 与其它4个栽培种的亲缘关系由近至远分别是C. chinense、C. frutescens、C. pubescens和C. baccatum。对C. annuum 24份不同类型材料聚类分析的结果与形态分类不能完全对应, 说明我国现行主要基于果实形态的变种分类体系不能准确反映C. annuum种质的遗传差异。本研究还发现中国云南西双版纳C. frutescens种质与美洲C. frutescens种质具有较大的扩增片段差异, 为进一步考证我国云南西双版纳地区也是辣椒起源地之一提供了新的证据。

RAPD Analysis of Phenogenic Relationship in Five Cultivated Capsicum Species

RAPD analysis was conducted in 31 accessions from 5 cultivated species in Capsicum. Thirty-one primers generated 276 scorable RAPD bands of which 244 were polymorphic. The percentage of polymorphic loci (PPB)and Shannon's information index (I) in C.annuum were 32.97% and 0.1599 respectively,indicating the genetic diversity within C. annuum was low. Jaccard's similarity between pairs of accessions ranged from 0.349 to 0.952 with a mean of 0.729. The results from cluster analysis showed that the genetic distances of C. annuum with other four species beginning with nearer were C. chinense, C. frutescens, C. pubescens and C. baccatum. The cluster formed by the 24 accessions of C. annuum did not fully correspond to the current morphologic classification, suggesting that the genetic differences among those accessions of C. annuum could not be precisely reflected by the current taxonomic system. Great diversity of amplification bands was observed between C. baccatum accession from Xishuangbanna, China and that from America, which provided us with new evidence to the argument that if the Xishuangbanna area in China was also a place for pepper origin.