Genetic Diversity of Geographic Populations of Scylla Paramamosain Based on ISSR Markers

The molecular marker technique of inter-simple sequence repeat(ISSR)was used to analyze the genetic diversity in three geographic populations of Scylla paramamoain,which were taken from Zhangzhou in Fujian,Fangchenggang and Beihai in Guangxi.A total of 63 loci from 60 individuals were amplified by polymerase-chain-reaction(PCR) with 10 primers.The Number of polymorphic loci were 56.The Nei's gene diversity of Fujian,Beihai and Fangchenggang populations was 0.2670,0.1819 and 0.2257,repectively.The Shannon's information index was 0.3945,0.2708 and 0.3371,repectively,showing that the abundance of genetic diversity in the three populations arranged in a decent order was FJFCBH.The Nei's gene diversity and Shannon's information index of Scylla paramamosain was 0.2248 and 0.3341 at species,0.3186 and 0.4337 at population level,respectively,showing that the genetic diversity of S.paramamosain was relatively high.An analysis of the molecular variance(AMOVA)demonstrated that the among-population component accounted for 32.34% of the total variation,while the within-population component accounted for 67.66%.The within-population genetic variation was apparently larger than the among-population.The genetic differentiation coeficient(Gst) among the three populations was 0.1542.There was genetic differentiation between Fujian and the other two populations.