乌龟选育世代遗传多样性及遗传结构的微卫星分析

Genetic diversity and genetic structure of selected generations of Chinese pond turtle(Mauremys reevesii)based on microsatellite DNA

为研究乌龟(Mauremys reevesii)优良品种的选育效果,利用多态性微卫星(simplesequence repeat,SSR)标记分析了乌龟5个选育世代(基础群体F0代、F1~F4代)的遗传多样性和遗传结构。结果表明:在筛选的12个微卫星位点中,共检测到等位基因数为103个,平均等位基因数(N_(a))为8.58,期望杂合度(H_(e))为0.173~0.919,平均值为0.581,观测杂合度(H_(o))为0.054~0.862,平均值为0.479,多态信息含量(PIC)为0.165~0.914,平均值为0.541;12个微卫星位点中,有11个位点属于中度或高度多态位点,表明所选择的微卫星位点可作为乌龟选育世代遗传多样性及遗传结构分析的良好评价工具;乌龟5个选育世代的观测杂合度(H_(o))分别为0.491、0.494、0.497、0.458和0.453;遗传分化系数F_(st)及AMOVA分析显示,乌龟5个选育世代群体之间的F_(st)值为0.004~0.012,小于0.05。研究表明,乌龟选育世代的遗传多样性有所下降,遗传分化程度较小,乌龟选育群体还有进一步选育的潜力。

In order to probe selective breeding effect of Chinese pond turtle(Mauremys reevesii),the genetic diversity and genetic structure were analyzed in five selective breeding generations of the wild and protospecies of Chinese pond turtle,including basic group F0 generation,and F1-F4 generation groups by polymorphic microsatellite(SSR)markers.The results showed that 103 alleles were detected in the 12 selected microsatellite loci,with the average allele number(H_(a))of 8.58.The expected heterozygosity(H_(e))was varied from 0.173 to 0.919,with mean of 0.581.The observed heterozygosity(H_(o))was found to be 0.054-0.862,with an average of 0.479.Polymorphic information content(PIC)was changed from 0.165 to 0.914,with average of 0.531.There were 11 moderately or highly polymorphic loci in the 12 microsatellite loci,indicating that the microsatellite loci selected in this study can be used as a good evaluation tool for the analysis of genetic diversity and genetic structure of selective breeding generations of Chinese pond turtle.The(H_(o))of the five selective breeding generations was 0.491,0.494,0.497,0.458 and 0.453,respectively.The genetic differentiation coefficient(F_(st))and AMOVA analysis revealed that the(F_(st))values between the five breeding generations were 0.004-0.012,less than 0.05.The findings indicated that the genetic diversity of the selective breeding generation of Chinese pond turtle was decreased,with less degree of genetic differentiation between five generations.Therefore,the selective breeding population of the Chinese pond turtle still has the potential further breeding.