摘要
为了揭示罗非鱼“粤闽1号”母本——尼罗罗非鱼Oreochromis niloticus的遗传背景及其选育群体世代间的遗传变异,采用13对荧光标记微卫星引物分析了罗非鱼“粤闽1号”母本3个不同选育世代(F2、F4和F6世代)的遗传多样性和遗传结构,并进一步分析了它们与高要(GY)、惠州(HZ)、茂名(MM)和无锡(WX)4个尼罗罗非鱼地理群体之间的遗传关系。结果表明:F2、F4和F63个选育世代的等位基因数、有效等位基因数、期望杂合度、Shannon指数和多态性信息含量等遗传多样性参数均呈现出随着选育世代增加而降低的趋势,但仍表现为高度多态性(PIC>0.5);4个尼罗罗非鱼地理群体的遗传多样性依次为GY群体>MM群体>HZ群体>WX群体,其中GY群体、MM群体和HZ群体的遗传多样性显著高于3个选育世代;随着罗非鱼“粤闽1号”母本的选育世代增加,世代间遗传距离(D_(a))逐渐增大(F2~F4的D_(a)=0.1556,F4~F6的D_(a)=0.3757),遗传分化系数(F_(ST))也逐渐升高(F2~F4的F_(ST)=0.0364,F4~F6的F_(ST)=0.1111);在UPGMA系统进化树中,3个选育世代群体与HZ群体、GY群体聚为一支,说明它们的遗传背景相近;罗非鱼“粤闽1号”3个选育世代母本的与4个地理群体中的GY、HZ和MM群体之间遗传分化中等,与WX群体之间遗传分化较大。研究表明:罗非鱼“粤闽1号”母本的选育群体在选育过程中遗传多样性出现下降趋势,遗传分化不断加剧,F6与F2、F4遗传分化中等,但仍保持着较高遗传多样性,具有进一步选育潜力;4个尼罗罗非鱼地理群体中GY群体的遗传多样性最高,与选育群体F6的遗传距离适中(D_(a)<0.54),可作为潜在的引种群体与罗非鱼“粤闽1号”母本的选育群体进行杂交,从而提高其遗传多样性。
In order to reveal the genetic background and genetic differentiation among maternel selective breeding generations of Nile tilapia Oreochromis niloticus“Yuemin No.1”,13 microsatellite loci were used to analysis the genetic diversity and genetic structure of three maternal selective breeding generations of tilapia“Yuemin No.1”(F2,F4 and F6),and then the genetic relationships were analyzed among the selective breeding generations and four geographical populations of Gaoyao population(GY),Huizhou population(HZ),Maoming population(MM)and Wuxi population(WX)of Nile tilapia.The results showed that there was a trend of decrease in genetic diversity parameters including the number of alleles,effective alleles,expected heterozygosity,Shannon diversity index and polymorphic information content with the increase in breeding generations in the selective breeding populations of F2,F4 and F6 generations which still had a highly ploymorphism(PIC>0.5).The descending order of genetic diversity in the four geographic populations was expressed as GY population>MM population>HZ population>WX population,significantly higher genetic diversity in GY population,MM population and HZ population than that in the F2,F4 and F6 populations(P<0.05).The genetic distances and genetic differentiation coefficients(F_(ST))between generations were gradually increased with the increase in breeding generation,with genetic distance of 0.1556 in F2-F4 and 0.3757 in F4-F6,and F_(ST) values of 0.0364 in F2-F4 and 0.1111 in F4-F6.F2,F4 and F6 generations were clustered with HZ population and GY population in the phylogenetic tree of UPGMA,indicating that they had similar genetic background.The GY population,HZ population and MM population had moderate genetic differentiation with the selective breeding generations,while the WX population had greater genetic differentiation in the three generations.In summary,the genetic diversity of the maternal selective breeding generations of tilapia“Yuemin No.1”showed a downward trend during the breeding process and the genetic differentiation was continuously intensified.The selective breeding populations still had a high genetic diversity.In addition,GY population with the highest genetic diversity and moderate genetic distance can be used as a potential population to hybridize with the maternal selective breeding generation of tilapia“Yuemin No.1”to improve the genetic diversity.
作者
刘志刚
曹建萌
高风英
可小丽
王淼
衣萌萌
卢迈新
LIU Zhigang;CAO Jianmeng;GAO Fengying;KE Xiaoli;WANG Miao;YI Mengmeng;LU Maixin(Key Laboratory of Tropical & Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China)
出处
《大连海洋大学学报》
CAS
CSCD
北大核心
2021年第1期16-22,共7页
Journal of Dalian Ocean University
基金
中国水产科学研究院中央级公益性科研院所基本科研业务费专项(2019ZX-003)
现代农业产业技术体系专项(CARS-46)
国家重点研发计划项目(2018YFD0901201)。
关键词
尼罗罗非鱼
选育世代
遗传差异
微卫星
Oreochromis niloticus
selective breeding generation
genetic diversity
microsatellite
