Comparative Analysis of Microsatellite DNA Polymorphism in Gold Grass Carp and Four Grass Carp Populations from China

[ Objectives ] To analyze the genetic structure and genetic diversity of gold grass carp population. [ Methods ] A total of 15 microsatellite markers were used to examine gold grass carp population and four grass carp populations[ Yuanjiang （YJ）, Ningxiang （NX） , Honghu （HH） and Xijiang （XJ） ] from the Yangtze River and the Pearl River of China. [ Results] All the 15 microsatellite loei were highly polymorphic, with polymorphism information content （PIC） of 0.763 -0.939. The expected heterozygosity （HE ） of gold grass carp population was 0. 662, lower than those of the four Chinese grass carp populations （HE = 0.85 - 0. 885 ）. The genetic differentiation index （ FST ） between gold grass carp population and YJ, NX, HH, XJ populations were 0. 157 2, 0. 129 5, 0. 147 5 and 0. 114 4, respectively. This suggests that gold grass carp population is highly differentiated from YJ grass carp population （0.15 〈 FST 〈0.25）, while moderately differentiated from other three grass carp populations （0.05 〈 FST 〈 0.15 ）. Gold grass carp population had the closest genetic relationship with XJ population （DA = 0.476 3）, and it showed the farthest genetic relationship with YJ grass carp population （DA = 0. 810 7）. The NJ phylogenetic tree based on genetic distance indicated that four Chinese grass carp populations clustered together as one branch, while gold grass carp population as another. [ Conclusions] Genetic di- versity of gold grass carp population is lower than that of Chinese grass carp population, with relative distant genetic relationship.