基于RSAP和SSR的辣椒优良自交系间遗传距离的估计与比较

作物F1代的杂种优势表现与亲本间的遗传距离直接相关,对自交系间遗传距离的估计可被用来预测杂种优势。针对我国鲜食尖椒的育种目标,利用RSAP和SSR标记系统,对来自国内外的10份尖椒优良自交系间的遗传距离进行估计,并比较了2种标记的结果和效力。结果显示,RSAP标记具有较高的位点和多态性检测能力,平均每次可检测51个位点和13个多态性条带,分别是SSR的17倍和6.5倍;基于RSAP的遗传距离和基于SSR的遗传距离相关性较高(r=0.542 9);2种标记系统的聚类结果基本一致,均将10份尖椒分为3大类,这种分类结果不但反映了果实形状在辣椒分类上的重要地位,而且与辣椒杂种优势育种实践相一致。

Estimation and comparison of genetic distances among elite inbred lines in hot pepper (Capsicum annuum L. ) by RSAP and SSR

Levels of heterosis exhibited by the F1 have a direct relationship with the divergence between their parents.Therefore,estimation of genetic distance can be useful for prediction of high performance crossings.Focusing on the breeding objectives of domestic long-fruit hot pepper variety type,two marker systems,i.e.restriction site amplified polymorphism(RSAP) and simple sequence repeat(SSR),were adopted to estimate the genetic distances among 10 elite inbred lines.The results showed that RSAP had the higher number of total loci(51) and polymorphic bands(13) per assay ratio,being 17-fold and 6.5-fold higher than SSR,respectively.The correlation between pairwise genetic distances generated by RSAP maker system and by SSR was high(r=0.542 9).The clusters of two marker systems were coincident and could classify ten long-fruit hot pepper varieties into three groups that were in accordance with the practice of pepper heterosis breeding and pepper fruit shapes.