长江、珠江和黑龙江草鱼双列杂交组合遗传变异的微卫星分析

Microsatellite analysis of genetic variation of diallel hybrid populations of grass carp (Ctenopharyngodon idellus) in three waters

为研究本课题组筛选获得的长江、珠江和黑龙江草鱼优秀种质间完全双列杂交组合遗传多样性及遗传结构的变化情况,采用多重PCR技术对构建的6组杂交组合[珠江♀×黑龙江♂(ZH)、黑龙江♀×珠江♂(HZ)、长江♀×珠江♂(CZ)、长江♀×黑龙江♂(CH)、珠江♀×长江♂(ZC)、黑龙江♀×长江♂(HC)]和3组自交组合[黑龙江♀×黑龙江♂(HH)、长江♀×长江♂(CC)及珠江♀×珠江♂(ZZ)]共9个草鱼组合群体进行微卫星遗传变异分析。结果显示,9个群体平均等位基因数(Na)为(5.75~12.33),平均有效等位基因数(Ne)为(3.8077~6.3065),平均观测杂合度(Ho)为(0.7682~0.9036),9个草鱼群体均显示出较高的遗传多样性水平,平均期望杂合度(He)为(0.8385~0.6210),12个草鱼微卫星位点的多态信息含量(PIC)分别为0.892、0.823、0.857、0.894、0.927、0.859、0.850、0.859、0.907、0.929、0.879和0.749,均表现为高度多态位点(PIC=0.749~0.929)。基于不同群体的Nei’s遗传相似性和遗传距离构建的UPGMA系统发育树显示,9个群体中黑龙江♀×珠江♂(HZ)与长江♀×珠江♂(CZ)首先聚类,表明两个组合亲缘关系更近,珠江♀×黑龙江♂(ZH)与黑龙江♀×长江♂(HC)组合遗传距离最远。本研究结果将为草鱼目前种质退化现象提供解决思路,为草鱼优良品系的选育提供理论依据。

In order to study the genetic diversity and genetic structure changes of the selected population through complete diallel crossing in Sanjiang River system,six groups of hybrid Progenies(PearlRiver♀×Heilongjiang River♂(ZH),Heilongjiang River♀×Pearl River♂(HZ),Yangtze River♀×Pearl River♂(CZ),Yangtze River♀×Heilongjiang River♂(CH),Pearl River♀×Yangtze River♂(ZC),Heilongjiang River♀×Changjiang River♂(HC),Heilongjiang River♀×Heilongjiang River♂(HH),Yangtze River♀×Yangtze River♂(CC)and Pearl River♀×Pearl River♂(ZZ)).The microsatellite sequence genetic variation of 9 grass carp populations was analyzed.The results showed that the average number of alleles Na)was(5.75-12.33),the average number of effective alleles Ne)was(3.8077-6.3065),the average observed heterozygosity(Ho)was(0.7682-0.9036),the average expected heterozygosity(He)was(0.8385-0.6210),and the polymorphism information content(PIC)of 12 microsatellite loci in 9 populations of grass carp was high.They were 0.892,0.823,0.857,0.894,0.927,0.859,0.850,0.859,0.859,0.907,0.929,0.879,0.749 and 0.869 respectively,showing high polymorphism loci(PIC is from 0.749 to 0.929).UPGMA phylogenetic tree based on Nei's genetic similarity and genetic distance of different populations showed that among 9 populations,Heilongjiang River♀×Pearl River♂(HZ)and Yangtze River♀×Pearl River♂(CZ)clustered first,indicating that the genetic relationship between the two combinations was closer,and the genetic distance between Pearl River♀×Heilongjiang River♂(ZH)and Heilongjiang River♀×Changjiang River♂(HC)combinations was the farthest.The purpose of this study is to provide reference value for grass carp breeding in the future,lay a foundation for further species renewal and genetic improvement of grass carp,at the same time,provide a solution to the current degradation of grass carp germplasm,and provide a theoretical basis for the breeding of grass carp fine strains.