Genetic differentiation analysis of maternal selective breeding generations of tilapia “Yuemin No.1” using microsatellites
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
Abstract: In order to reveal the genetic background and genetic differentiation among maternel selective breeding generations of Nile tilapia Oreochromisniloticus “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 (FST) between generations were gradually increased with the increase in breeding generation, with genetic distance of 0.155 6 in F2-F4 and 0.375 7 in F4-F6, and FST values of 0.036 4 in F2-F4 and 0.111 1 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.
刘志刚, 曹建萌, 高风英, 可小丽, 王淼, 衣萌萌, 卢迈新. 罗非鱼“粤闽1号”母本选育群体世代间遗传差异的微卫星分析[J]. 大连海洋大学学报, 2021, 36(1): 16-22.
LIU Zhigang, CAO Jianmeng, GAO Fengying, KE Xiaoli, WANG Miao, YI Mengmeng, LU Maixin. Genetic differentiation analysis of maternal selective breeding generations of tilapia “Yuemin No.1” using microsatellites. Journal of Dalian Ocean University, 2021, 36(1): 16-22.
2021, Vol. 36 
