凡纳滨对虾连续3个世代选育群体的遗传多样性分析  

Genetic diversity of three consecutive generations of Litopenaeus vannamei

作　　者：彭敏 陈慧芳 李强勇 杨春玲 曾地刚 刘青云 赵永贞 陈晓汉 林勇 陈秀荔 PENG Min;CHEN Hui-fang;LI Qiang-yong;YANG Chun-ling;ZENG Di-gang;LIU Qing-yun;ZHAO Yong-zhen;CHEN Xiao-han;LIN Yong;CHEN Xiu-li(Guangxi Academy of Fishery Sciences/Key Laboratory of Aquatic Genetic Breeding and Health Cultivation of Guangxi,Nanning 530021,China;College of Animal Science and Technology,Guangxi University,Nanning 530005,China)

机构地区：[1]广西水产科学研究院/广西水产遗传育种与健康养殖重点实验室,南宁530021 [2]广西大学动物科学技术学院,南宁530005

出　　处：《南方农业学报》2020年第6期1442-1450,共9页Journal of Southern Agriculture

基　　金：广西创新驱动发展专项(桂科AA17204088-1);广西科技计划项目(桂科AB16380067);国家现代农业产业技术体系广西创新团队建设项目(nycytxgxcxtd-14-01);广西水产畜牧科技推广应用项目(桂渔牧科201633015)。

摘　　要：【目的】明确凡纳滨对虾连续3个世代选育群体的遗传变异情况及近亲繁殖对个体生长速度和抗病性的影响,为凡纳滨对虾种质改良提供理论依据。【方法】从GenBank收录的微卫星(SSR)引物序列中筛选11对能有效扩增的SSR引物,对2016—2018年桂海1号凡纳滨对虾连续3个世代选育群体(合计853个样品)进行遗传多样性分析,监测相邻2个世代选育群体间的遗传变异情况。【结果】11对SSR引物在凡纳滨对虾连续3个世代选育群体中共检测到103个等位基因,各SSR位点的等位基因数(Na)平均为9.3636个,有效等位基因数(Ne)平均为3.8355个,观测杂合度(Ho)平均为0.4794,期望杂合度(He)平均为0.7074,多态信息含量(PIC)平均为0.6708;除TUMXLv10.33位点呈中度多态性(0.25<PIC<0.50)外,其余10个SSR位点均为高度多态性。凡纳滨对虾连续3个世代选育群体的平均PIC分别为0.6689、0.6657和0.6650,即均属于高度多态性(PIC>0.50);对应的平均Na为8.7272、7.3636和8.0000个,平均Ne为3.8676、3.7654和3.8010个,平均Ho为0.3975、0.5224和0.4876,平均He为0.7057、0.7057和0.7029。Hardy-Weinberg平衡检测结果显示,绝大部分SSR位点偏离Hardy-Weinberg平衡。凡纳滨对虾连续3个世代选育群体在11个SSR位点上的遗传分化系数(Fst)均小于0.0500,即凡纳滨对虾群体的遗传分化很小;凡纳滨对虾群体内近交系数(Fis)介于-0.0101~0.8098,平均为0.3543,且除C11654位点为负值外,其余SSR位点均为正值,表明凡纳滨对虾连续3个世代选育群体的近交程度较高。分子方差分析(AMOVA)结果显示,69.78%的遗传变异来源于凡纳滨对虾个体内,而29.96%的变异来源于凡纳滨对虾个体间。【结论】桂海1号凡纳滨对虾各世代选育群体尚具有较丰富的遗传变异,但群体遗传结构处于不稳定状态。因此,今后应通过人工选育方式保留有利突变、淘汰有害突变,同时避免近亲繁殖,或引进优质品种进行杂交以扩【Objective】To clarify the genetic variation of three consecutive generations of Litopenaeus vannamei and the influence of inbreeding on individual growth rate and disease resistance,and provide a theoretical basis for the improvement of L.vannamei germplasm.【Method】Using 11 pairs of effectively amplified SSR primers selected from the sequence of microsatellite(SSR)primers collected by GenBank,the genetic diversity of L.vannamei Guihai No.1 breeding population for three consecutive generations(2016-2018)(853 samples)was analyzed to monitor the genetic diversity be tween two adjacent generation breeding populations.【Result】Using the 11 pairs of SSR primers,103 alleles were detected in the three consecutive L.vannamei generations.The average number of alleles(Na)at each SSR locus was 9.3636,and the average number of effective alleles(Ne)was 3.8355,the average observed heterozygosity(Ho)was 0.4794,the average expected heterozygosity(He)was 0.7074,and the average polymorphic information content(PIC)was 0.6708;except that TUMXLv10.33 locus was moderately polymorphic(0.25<PIC<0.50),the remaining 10 SSR loci were all highly polymorphic.The average PIC of the three consecutive L.vannamei generations were 0.6689,0.6657 and 0.6650,respectively,which were all highly polymorphic(PIC>0.50).The corresponding average Na were 8.7272,7.3636 and 8.000,and the average Ne were 3.8676,3.7654 and 3.8010,the average Ho were 0.3975,0.5224 and 0.4876,the average He were 0.7057,0.7057 and 0.7029,respectively.Hardy-Weinberg balance test showed that most SSR sites deviated from Hardy-Weinberg balance.The genetic differentiation coefficients(Fst)at the 11 SSR sites of the three consecutive L.vannamei generations were all less than 0.0500,indicating that the genetic differentiations of the L.vannamei populations were very small.The inbreeding coefficient(Fis)was-0.0101-0.8098,with an average of 0.3543,and except for the C11654 locus was negative,the rest of the SSR loci were positive,indicating a high degree of inbreeding among thr

关 键 词：凡纳滨对虾 选育群体 微卫星(SSR)分子标记 遗传多样性 遗传变异 

分 类 号：S917.4[农业科学—水产科学]