基于果实品质与EST-SSR标记的刺梨居群遗传多样性分析及核心种质构建

通过分析评价野生刺梨(Rosa roxburghii Tratt.)资源居群遗传多样性和遗传结构,同时构建核心种质,为刺梨资源的保护和发掘利用提供科学依据。本研究利用10对EST-SSR引物和9个果实品质性状指标对收集的12个刺梨自然居群(共102份种质)的遗传多样性及遗传结构进行分析,同时结合原贵州省32份初级核心种质,采用位点优先取样策略进一步构建西南地区核心种质。结果表明,黔西(QX)居群拥有最高的Shannon信息指数I=0.6965,基因多样性指数h=0.3935,多态位点百分率p=84.62%;而古丈(GZ)居群则无论在分子数据还是表型数据都表现为遗传多样性最低;AMOVA分析表明刺梨居群内遗传变异在87%以上,居群间基因流Nem在3.5以上、平均Nei’s遗传距离(GD)0.223。构建的19份核心种质等位基因保留率和稀有等位基因保留率均为100%,能够代表原种质的遗传多样性。西南地区野生刺梨的遗传变异主要发生在居群内,居群间具有基因交流频繁、Nei’s遗传距离小等特点,构建的19份核心种质从等位基因保留率、稀有等位基因保留率及地理分布均能够较好地代表原种质的遗传多样性。自然居群以黔西(QX)居群遗传多样性最高。因此,野生刺梨的保护策略可采用就地保护黔西(QX)居群与迁地保护19份核心种质相结合的方法进行。

Genetic Diversity Analysis and Core Collection Construction in Rosa roxburghii Based on Fruits Quality and EST-SSR Markers

Wild Rosa roxburg hii resources population genetic structure and genetic diversity were analysed and evaluated to construct the core collection and provide a scientific basis of the protection and excavation of Rosa roxburghii resources.10 EST-SSR primers and 9 fruit quality traits were used to analyze the genetic diversity and population structure within 12 populations including 102 R.roxburghii germplasms by POPGENE 1.31 and GenAlEx 6.502.At the same time,the core collection was constructed using the allele preferred sampling strategy from102 new accessions and 32 core collections in Guizhou province.The results showed that the population QX had the highest genetic diversity(I=0.6965,h=0.3935,p=84.62%)and the population GZ had the lowest diversity parameters both in molecular data and phenotypic data.AMOVA a nalyses indicated that at least 87%of the genetic diversity occurred within populations.And gene flow estimate of 3.5 showed a high level of gene flow among populations.The average Nei’s genetic distance calculated among the 12 populations was 0.223.The retention rates of both alleles and rare alleles of 19 core collections were 100%,which could represent the genetic diversity of the original accessions.The vast majority of genetic variation of Rosa roxburghii in southwest China occur within populations.And among populations,it has the characteristics of frequent gene exchange,and small Nei’s genetic distance.The 19 core collection can represent the genetic diversity of the original germplasm at allele retention rate,rare allele retention rate and the regional distribution.The population QX had the highest genetic diversity.Therefore,the conservation strategy of wild R.roxburghii can be carried out by combining the local protection of QX population and the relocation protection of 19 core collections.