基于ISSR标记的福建省钩锥遗传多样性分析

Genetic diversity analysis on five populations of Castanopsis tibetana from Fujian Province based on ISSR marker

关键词:  钩锥， ISSR标记， 遗传多样性， 基因分化， 聚类分析

Key words:  Castanopsis tibetana, ISSR marker, genetic diversity, gene differentiation, cluster analysis

摘要:

该研究利用ISSR分子标记，对分布于福建省内5个样地( 邵武、建阳、建瓯、周宁和屏南)的61个野钩锥(Castanopsis tibetana)单株的遗传多样性进行了分析，并采用聚类分析方法探讨了它们的遗传关系。结果表明： 用10条ISSR引物从61个单株的基因组DNA共扩增出158条带，包含145条多态性条带，多态性条带百分率达91.77%，其中引物 UBC817、UBC819与UBC842的多态性条带百分率（PPB）为100.0%。各居群的多态性条带百分率(PPB)、有效等位基因数(Ne)、Nei’s基因多样度(H)和Shannon’s多样性指数（I）等各遗传指数差异较大，其中各项遗传指标中最高的为邵武居群，而周宁居群则最低。5个居群的基因分化系数和基因流分别为0.144 0和2.973 0，说明5个居群总遗传变异的14.40%存在于居群间，85.60%存在于居群内。种间总基因多样度分别为0.395 8，种内基因多样度分别为0.338 8，表明钩锥种间遗传多样性较高，且种间变异大于种内变异。各居群间的遗传距离差异较大； 其中，邵武与建瓯居群的遗传距离最近，仅为0.081 5； 建阳和周宁居群的遗传距离最远，为0.162 9。通过聚类分析可将5个钩锥居群聚为3支，屏南与周宁的居群各自独立聚为2支；来自邵武、建瓯及建阳的居群聚为一支，且可进一步分为两个亚支，建阳居群为1个亚支，邵武和建瓯居群聚为1个亚支。供试的钩锥具有较高的遗传多样性，存在着较为频繁的基因交流。该研究结果较准确地揭示了钩锥种间的遗传多样性。

Abstract:

Castanopsis tibetana is an evergreen hard wood tree of red Castanopsis, which is one of the excellent commercial tree species. C. tibetana has great development prospect and ecological value in China. In this paper， the genetic diversity of 61 individuals of C. tibetana collected from five plots (Shaowu， Jianyang, Jianou, Zhouning and Pingnan) in Fujian Province of China was analyzed by means of inter simple sequence repeat（ISSR） marker, and the genetic relationship among these individuals also was discussed by cluster analysis method. The results showed that 158 bands were amplified from genomic DNA of 61 C. tibetana individuals by ten inter simple sequence repeat （ISSR）primers, and there were 145 polymorphic bands with percentage of polymorphic band of 91.77%, in which, the percentage of polymorphic band of UBC817, UBC819 and UBC42 reached 100.0%. Percentage of polymorphic band(PPB), effective number of alleles (Ne), Nei’s gene diversity (H) and Shannon’s diversity index (I) were obviously different among five C. tibetana populations，in which all indexes of population in Shaowu were the highest，populations in Zhouning was the lowest. Gene differentiation coefficient and gene flow of five populations was 0.144 0 and 2.973 0，respectively, indicating that 14.40% of overall genetic variation of five populations exists among populations and 85.60% within populations. The gene diversity among species (Ht) and within species (Hs) were 0.395 8 and 0.338 8. It is suggested that the genetic diversity among species of C. tibetana was relatively rich and the interspecies variation degree was higher than intraspecies. Genetic distance among all populations differed obviously, and the genetic distance, between populations of Shaowu and Jianou was the nearest (only 0.081 5) while that between populations of Jianyang and Zhouning was the farthest (0.162 9). Five populations could be divided into three groups by cluster analysis, in which populations of Pingnan and Zhouning were two separate groups，while three populations of Shaowu，Jianou and Jianyang were gathered into one group, which could be divided into two sub groups further, one was Jianyang population and another contained populations of Shaowu and Jianou. It is suggested that populations of C. tibetana tested possessed higher genetic diversity, and there were frequent gene exchange. The genetic diversity of C. tibetana could be accurately revealed by means of ISSR marker analysis．