GENETIC DIVERSITY ANALYSIS OF FARMING GROUPS OF Scylla paramamosain IN CHINA ESTIMATED BY MICROSATELLITE MARKERS

Our recent research has identified that the mud crab, Scylla paramamosain, in China may be sub-divided into northern and southern population. There were some biological differences among different populations. The seedlings of mud crab farming in China mainly came from natural sea. Whether the farming location of different population seedling is in line with its natural distribution will have a significant impact on the farming effect. To this end, the present study analyzed the genetic diversity of different farming groups of S. paramamosain in China. S. paramamosain is distributed only along the coastal areas of southeast China in the south of the estuary of Yangtze River. In the present study, six wild groups were collected. The collect locations from north to south were as follow: Ninghai (NH) of Zhejiang province, Langqi (LQ) near Fuzhou of Fujian province, Longhai (LH) near Xiamen of Fujian province, Zhaoan (ZA) in the south of Fujian province, the estuary of Zhujiang River (ZJ) of Guangdong province, and Dongzhai (DZ) of Hainan province. At the same time, two farming groups of the northerly location were also collected from Wenzhou (WZ) of Zhejiang province and Ningde (ND) of Fujian province. Six polymorphic microsatellite loci were used to estimate the genetic diversity of the farming groups and construct the UPGMA tree with the wild groups. A total of 129 alleles were detected in 62 individuals of these two farming groups. Both two farming groups showed high level of genetic diversity. The mean allele number for WZ and ND group were 16.333 and 17.667, the mean He and Ho for WZ and ND group were 0.8672, 0.8900 and 0.8490, 0.8778, respectively. Among 12 population loci, 1 showed significant deviation from the Hardy-Weinberg equilibrium. The UPGMA results showed that WZ farming group was closely clustered with ZA wild group, and ND farming group was closely clustered with DZ wild group. This means that the seedlings of two farming groups of the northerly location were probably captured from the wild coastal sea of ZA and DZ of the southerly location. The result suggested that the seedlings of north and south population were mixed in the farming of S. paramamosain in China. It's worthy to pay attention to this situation since the mix of the seedlings of north and south population may have certain impact on the effect of farming of S. paramamosain .

Acknowledgements

This work was supported by a grant (31472294) from National Natural Science Foundation of China (NSFC).