日本沼虾不同地理种群的遗传多样性研究

本文采用随机扩增多态DNA（RAPD）技术对6个地理种群（微山湖、洪泽湖、太湖、龙感湖、洪湖、珠江）的日本沼虾各30个个体进行了遗传多样性分析。在筛选出的18个引物中共检测到201个位点，大小在100～2000bp之间。多态位点141个，多态位点比例70.15％；各种群的多态位点数为30～99不等，多态位点比例为21.13%～55.93%。日本沼虾中国不同地理种群的平均遗传杂合度为0.2446，各种群内平均遗传杂合度为0.1132～0.2071。Shannon信息指数（I）为0.1695～0.2950。日本沼虾6个地理种群的两两地理种群间遗传分化指数Gst值在0.2116～0.4442之间，种群间总的遗传分化指数Gst0值为0.4858，Nm值在0.6257～1.8628之间，表明日本沼虾种群间已经发生显著或重要分化。同时发现OPX－830bp、OPI－360bp为珠江种群区别于其他种群的特征标记。聚类分析结果表明，洪湖种群与龙感湖种群，洪泽湖种群与微山湖种群分别先聚在一起，再与太湖种群聚类，最后与珠江种群聚合在一起。

STUDIES ON GENETIC DIVERSITY OF MACROBRACHIUM NIPPONENSE OF DIFFERENT GEOGRAPHIC POPULATIONS

Random Amplified Polymorphic DNA (RAPD) was applied to investigate the genetic diversity of six geographic populations of Macrobrachium nipponense, which were collected from the Weishan Lake(WL), Hongze Lake(HzL), Taihu Lake(TL), Longgan Lake(LL), Honghu Lake (HL) and Pearl River(PR). Under optimal conditions, 18 random primers from OPI, OPM, OPP, OPX, were chosen to analyze their genomic DNA (30 individuals of each population). A total of 201 RAPD fragments ranged 100bp~2000bp were obtained, 141 of which were polymorphic (70.15%). For different populations, the proportions of polymorphic loci were 21.13%～55.93%, mean expected heterozygosity varied from 0.1132 to 0.2071, and the Shannon index (I) varied from 0.1695 to 0.2950. Index of genetic diversity Gst ranged from 0.2116to 0.4442 for different populations, and index of genetic diversity Gst0 was 0.4461. Nm ranged from 0.6257 to 1.8628. Results indicated that notable genetic divergence emerged between populations. Clustering of the stocks was analyzed by UPGMA, the results showed that Hongze Lake and Weishan Lake populations, Honghu Lake and Longgan Lake population clustered first respectively, then they clustered with Taihu Lake population, the last did Pearl River population.