中国板栗品种(系)DNA指纹图谱构建及其遗传多样性分析

Construction of DNA Fingerprint Map and Analysis of Genetic Diversity for Chinese Chestnut Cultivars(Lines)

基于SSR荧光分子标记,对中国342个板栗品种(系)构建了DNA指纹图谱,并解析了各品种群间的亲缘关系和遗传分化特征。结果表明:(1)所有SSR标记多位点匹配后的PI和PIsibs值分别为4.960×10-20和2.395×10-8,显示本试验所选用的标记指纹识别潜力强;对342份品种(系)构建指纹图谱,共获得338个有唯一对应关系的指纹信息,其中舒城大红袍与焦扎、双合大红袍与CSB-1两两共享了一个指纹信息,结合主要植物学性状,推测其为同物异名品种;同时发现存在大于10个位点信息差异的19份同名资源,判定其为同名异物品种。(2)两两品种群的Fst平均值为0.0224(Fst<0.05),表明品种群间遗传分化程度较低;对5个品种群进行了基因流(Nm)和AMOVA分析,遗传变异主要存在于个体内,占总变异的84%,各品种群间的平均基因流为6.592,表明资源间存在着广泛的基因交换,制约了各群体间的分化。(3)利用位点数据进行群体结构、主坐标和聚类树分析表明,板栗品种资源主要被划分为南、北两大品种群,确定了沿大别山山脉的湖北东北部、河南南部和安徽中北部、以及山东南部和江苏北部地区为分界带(混交地带)。

The DNA fingerprint map of 342 chestnut cultivars(lines)was constructed using SSR fluorescent molecular markers as well as the genetic relationship and genetic differentiation were further illuminated among the cultivar groups in the current investigation.The results showed that:(1)The PI and and PIsibs values of all the markers combined were 4.960×10-20 and 2.395×10-8,respectively,indicating that the 21 markers used in this study had excellent potential for fingerprint recognition.A total of 338 unique corresponding fingerprint information were obtained from 342 cultivars(lines).Among them,‘Shucheng Dahongpao’shared only one fingerprint information with‘Jiaoza’,similarly for‘Shuanghe Dahongpao’and‘CSB-1’.Combined with the main botanical traits,these cultivars(lines)were finally speculated to be synonym.Simultaneously,19 same-named cultivars(lines)with more than ten loci differences were identified as homonym.(2)The average Fst of each pairwise of chestnut cultivar groups was 0.0224(Fst<0.05),which demonstrated that there was low genetic differentiation among cultivar groups.Subsequently,gene flow(Nm)and AMOVA were carried out on the five cultivar groups.The genetic variation of chestnut cultivars(lines)mainly was found in individuals,accounting for 84%of the total variation.The average gene flow among cultivar groups was 6.592,revealing extensive gene exchange and restricting differentiation among chestnut cultivar groups.(3)From analyzing the population structure,principal coordinates and cluster tree via the site data,it could be seen that all chestnut cultivars(lines)were mainly divided into two major groups,the north and the south.Meanwhile,a region of northeastern Hubei,southern Henan,and north-central Anhui along the Dabie Mountains and the southern Shandong,the northern Jiangsu constituted the boundary zone(mixed zone)of two groups.