基于ISSR标记的钩栗遗传多样性分析

摘要

The genetic diversity of nine Castanopsis tibetana Hance populations were analyzed using inter-simple sequence repeat (ISSR) markers. 10 ISSR primers were screened out from l00 primers from UBC for amplifying 111 genomic DNA of Castanopsis tibetana using ISSR-PCR. 158 intensive bands were amplified, among which there were 141 polymorphic bands. The polymorphic loci percentage (P) was 89.01%. The Nei’s genetic diversity index, Shannon’s information, number of total genetic diversity index, genetic diversity index are 0.3323, 0.4920, 0.4108, 0.3346. They showed that genetic diversity of Castanopsis tibetana was high. Genetic differentiation coefficient (Gst) of Castanopsis tibetana were 0.1855, it indicated that the variation within population account 81.45%. The results by AMOVA analysis indicated that the variation within population account for 80.21% and variation among populations accounted for 19.79% . As analyzed by NTSYS, the genetic similarity ranged from 0.811 6 to 0.921 8 based on DICE. The genetic relationships among the 111 materials were relatively close. Genetic distance among all populations differs obviously, in which, that between populations of Shaowu and Jianou is the nearest(only 0.0815) while that between populations of Liuyang and Zhouning is the farthest (0.1984). Cluster analysis showed that Shaowu, Jianou, Jianyang, Pingnan and Zhouning populations clustered together. Enshi and Sangzhi population grouped together. Yongshun grouped together with Liuyang population. It was a further indicator that genetic variation of populations and its geographic pattern was basic consistency. It is suggested that populations of Castanopsis tibetana Hance tested possess higher genetic diversity,and there are frequent gene exchange. The genetic diversity of Castanopsis tibetana Hance can be accurately revealed by means of ISSR marker analysis.%利用 ISSR 分子标记对钩栗 Castanopsis tibetana Hance 9个野生居群进行了遗传多样性分析。利用100条引物分别对111份钩栗基因组 DNA 进行 PCR 扩增，共扩增出158条清晰条带，其中多态性条带141条，多态性条带百分率（P）平均为89.01%。钩栗9个居群的 Nei’s 基因多样性指数、Shannon’s 信息指数分别为0.3323、0.4920；总种群基因多样度（Ht）、各种群基因多样度分别为（Hs）0.4108、0.3346，表明钩栗的遗传多样性较高。9居群的基因分化系数 Gst 为0.1855，占总遗传多样性的81.45%。分子方差分析表明，80.21%的遗传差异存在于群体内，19.79%的遗传差异存在于群体间。基因流为2.1960。用 NTSYS 软件计算出9居群111材料的 DICE 相似系数在0.8116～0.9218之间，遗传亲缘关系较近。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0.0815；浏阳和周宁居群的遗传距离最远，为0.1984。聚类分析结果表明，采自福建的邵武、建瓯、建阳、屏南和周宁居群聚在一起；恩施和桑植居群聚在一起；永顺和浏阳居群聚为一起，种群遗传变异分布模式基本上与其地理生态格局一致。研究结果表明：供试的钩栗具有较高的遗传多样性，存在着较为频繁的基因交流；基于 ISSR 标记分析能较准确地揭示出钩栗种间的遗传多样性。