Studies On Genetics Diversity And Genetic Strcture Of Oriental River Prawn Macrobrachium Nipponense In The Poyang Lake Basin

Macrobrachium nipponense is the most important economic freshwater prawn which has the largest production in China. Jiangxi province is rich in surface water resources and river prawn resources. In Jiangxi province, Poyang lake is the the largest fresh-water lake and Ganjiang river is is the longest river. It’s very important to study on genetic resources of M. nipponense for the germplasm conservation, exploration and utilization. In this paper, 33 populations of the M.nipponense were collected: 15 populations in Poyang Lake, 18 populations in Ganjiang River. Using SSR markers, which were isolated in our lab to analyze the genetic diversity and population structure of M. nipponense. Main contents are as follows.1. Microsatellite analysis of genetic diversity in 15 populations of M. nipponense in Poyang Lake.10 microsatellite DNA locis were used to investigate genetic diversity of 15 populations of oriental river prawn Macrobrachium nipponense were collected from Poyang Lake. The results showed that the number of total alleles of these 10 microsatellite locis is 129; at least 5 loci in each population were with significant heterozygosity deficiency, there was significant deviation from Hardy-Weinberg Equilibrium in all stocks and all the 10 locis were highly polymorphic. Xinchi population has the highest genetic diversity, whereas Hukou population the lowest. Bottleneck and mutation-drift equilibrium test showed that the bottleneck effect is not observable among 15 populations and the number of each population has not fallen. FST and AMOVA analysis across all populations and locis indicated that there was low level of divergence among the 15 populations for the significant genetic differentiation (FST=0.04709, P<0.01). The above conclusions showed populations of oriental river prawn Macrobrachium nipponense in Poyang Lake can be used for identification conserve and management of strains.2. Genetic Diversity and Population Genetic Structure of M.nipponense in Ganjiang river valley.Genetic diversity and population genetic structure of 18 wild populations of M.nipponense in Ganjiang river valley were investigated using 10 microsatellite DNA locis. The results showed that the number of total alleles of these 10 microsatellite locis is 134; at least 3 locis in each population were with significant heterozygosity deficiency except few populations. All of the 18 populations in Ganjiang river valley showed high genetic diversity, and Yuanshui population has the highest genetic diversity, whereas Xingan population the lowest. Bottleneck and mutation-drift equilibrium test showed that the bottleneck effect is observable among 18 populations, and recently the number of each population has fallen. FST and AMOVA analysis across all populations and locis indicated that there was low level of divergence among the 18 populations for the significant genetic differentiation (FST=0.03119, P<0.01).3 .A comparative study on the genetic diversity and population structure of M. nipponense between Ganjiang river valley populations and Poyang Lake.A Comparison and Analysis on genetic diversity and population structure of M. nipponense between Ganjiang river valley populations and Poyang Lake. The results showed that Dabawai population has the most average number of alleles, whereas Wanhu population the fewest among 33 M. nipponense populations, and All of the 33 populations showed high genetic diversity, and Yuanshui population has the highest genetic diversity, whereas Xingan population the lowest. FST and AMOVA analysis across all populations and loci indicated that the level of divergence among Poyang Lake populations is a little higher than Ganjiang river valley populations. The UPGMA clustering tree based on DA genetic distance demonstrated that Ganjiang river valley populations clustered into one group, Poyang Lake populations clustered into another group, except Yudu population.