Genetic diversity and genetic structure of four brooder populations and one captive population of black bream Megalobrama terminalisin the middle and lower reaches of Qiantang River by microsatellite marker
Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
Abstract: In order to master the genetic diversity and genetic structure of different populations of black bream Megalobramaterminalis，the genes were amplified and genotyped in 768 samples in four broodstock populations including Jingshan (JS) and Mingxing (MX) populations in Huzhou, and Guali Baisong (GLZ) and Xiaoxiang (XX) populations in Hangzhou and one captive population of black bream in the middle and lower reaches of the Qiantang River using microsatellite molecular markers combined with capillary electrophoresis genotyping based on 8 pairs of fluorescent-labeled SSR primers. The results showed that the average number of alleles (Na) was 10±1 to 39±7 per locus for each population, with average number of effective alleles (Ne) from 6.60±0.98 to 14.22±3.08, and the average Shannon’s index (I) value from 2.02±0.14 to 2.85±0.21 for the 5 populations. The minimal average values of Na, Ne and I were observed in the MX population, higher in the captive population than those in the other populations. The average value of observed heterozygosity (Ho) was 0.96±0.02 to 0.98±0.01, higher than those of expected heterozygosity (He) in most loci for the 5 populations. AMOVA analysis revealed that there was 5.53% of genetic variation among the populations and 94.47% of genetic variation within populations. The genetic differentiation among 4 broodstock populations was shown to be mild (0<FST<0.05), to be the genetic differentiation between the captive population and some broodstock populations (such as JS and XX) to be medium (0.05<FST<0.15). Both structure analysis and PCoA analysis got the consistent results, indicating that all individuals were divided into two genetic clusters. One cluster consisted of most individuals from the captive population, the other cluster consisted of almost all individuals from 4 broodstock populations and a few individuals from the captive population. The findings revealed that there was a higher level of genetic diversity in populations in the middle and lower reaches of the Qiantang River, and heterozygote excess and loss of some alleles occurred wide spreadly in broodstock populations.
张敏莹, 方弟安, 周彦锋, 任泷, 郑宇辰, 徐东坡. 基于微卫星标记的钱塘江中下游三角鲂亲本群体和自然捕捞群体遗传多样性及遗传结构[J]. 大连海洋大学学报, 2022, 37(5): 775-783.
ZHANG Minying, FANG Di’an, ZHOU Yanfeng, REN Long, ZHENG Yuchen, XU Dongpo. Genetic diversity and genetic structure of four brooder populations and one captive population of black bream Megalobrama terminalisin the middle and lower reaches of Qiantang River by microsatellite marker. Journal of Dalian Ocean University, 2022, 37(5): 775-783.
2022, Vol. 37 
