基于叶绿体SSR单倍型分析普通杏演化关系

Phylogenetic Relationship Analysis of Common Apricot( Prunus armeniaca L. ) Revealed by Chloroplast SSR Haplotypes

为了研究普通杏的起源和不同品种群间的演化关系,以梅为组外对照,利用9对叶绿体SSR引物检测了来自不同品种群或野生类型的58份普通杏种质资源单倍型变化,并对单倍型网络演化进行了分析。共检测到22个等位基因,组成15个单倍型。普通杏以单倍型H01、H02和H03为优势单倍型,出现的频率分别为41.38%、17.24%和15.52%。除华南品种群外,其他品种群的栽培杏均以优势单倍型为主;西北地区的普通杏仅有单倍型H01、H02和H03,而新疆伊犁河谷的野生普通杏仅有2种单倍型H01和H02。同时,在东北品种群、华南品种群和西南地方品种中检测的单倍型数目均多于主栽产区。进一步对这些单倍型进行系统进化分析和网络图分析,发现所有单倍型可分为以H02为中心和以H01、H03为中心的2支,单倍型H01、H02位于网络图的中心。普通杏的叶绿体基因组进化较为保守,仅在较少部位产生了序列变异。在普通杏扩散过程中,边缘地区的种质资源不仅在基因组上存在着较多的基因渗透现象,而且其本身的基因组序列也产生了较多的适应性变异。

In order to investigate the origin of apricot and genetic variation among local populations（ Prunus armeniaca L.） here we analyzed the haplotype diversity of 58 wild and common apricot accessions by using 9 pairs of polymorphic chloroplast SSR markers. Twenty-two alleles were detected consisting of 15 haplotypes. H01（ haplotype 01）,H02 and H03 were 3 dominant haplotypes,which had the highest frequency in common apricot. The other haplotypes had lower frequency and 8 of them occurred only once which could be considered as rare haplotypes.H05 was detected only in Prunus mume（ Sieb.） Sieb. Zucc. Although most of the cultivars groups had dominant haplotypes（ except for Southern China cultivars group）,the type and number of haplotypes in different cultivars groups were significantly different. The common apricot in Northwest China had only 3 dominant haplotypes,while the wild common apricot in the Ili River valley in Xinjiang had only 2 dominant haplotypes but no other haplotypes.At the same time,the number of haplotypes detected in the Northeast China cultivars group,the Southern China cultivars group and the Southwest local cultivars were more than those of the major producing regions. The phylogenetic tree of 15 haplotypes showed that all common apricot haplotypes were clustered into 2 major branches. The first branch is based on H01 and H03,while the second branch is based on H02. The dominant haplotypes H01 and H02 were in the center of the median-joining network and the other haplotypes were distributed around the dominant haplotypes. It was suggested that most haplotypes in common apricot were evolved from the dominant haplotypes.The rare haplotypes were 1 or 2 mutation steps from H01 and H02,which indicating that they were variation types based on H01 and H02. The semi-wild germplasm resource in Southwest China,Southern China and Northeast China had more rare haplotypes than common apricot in the major producing regions. Only few of mutations in chloroplast genome of common apricot vs. wild apricot were detected. Thus,this work speculated that along with the spreading process of the common apricot,the germplasm resource in cultivars groups differed to the center of origin such as Southwest China,Southern China and Northeast China cultivars groups that maintained higher frequency of introgressions and mutations in their chloroplast genome.