Genetic Diversity Analyses Of Sillago Sihama Using AFLP Marker

Sillago sihama spreads widely in Red rea,Indian Ocean and Pacific Ocean ,also distributed in China coast , particular has a higher yield in western Guangdong. So far, researching works relevant with Sillago sihama were confined in the study of ecosystems. Researchs on genetic diversity of Sillago sihama has not been carried out fully. Especially , genetic variance was not analyzed by molecule markers. We needed to know whether genetic diversity was declined or not , so to find evidences for artificial breeding of Sillago sihama.The author studied the genetic diversity of 120 individuals in four Sillago sihama groups of HaiNan (HN),ShanWei(SW),ZhanJiang(ZJ),YangJiang(YJ) , calculated the genetic distance among every group, established the phylogenetic tree among populations. These works will benefit the protesting of resources of Sillago sihama , also provide theory evidences for artificial breeding of Sillago sihama.The main results from AFLP fingerprinting and cluster analysis indicated:1. Adopting 14 primer pairs to analyse the genetic diversity of Sillago sihama , there are 392 amplified sites with 333 polymorphic sites, polymorphism proportion is 85.05%. In the analysis of HaiNan Sillago sihama group, We got 213 polymorphic sites, the polymorphism proportion is 54.21%; there are 198 polymorphic sites in ShanWei Sillago sihama group, the polymorphism proportion is 50.51%; 175 polymorphic sites in ZhanJiang Sillago sihama group, the polymorphism proportion is 44.55%; 156 polymorphic sites in YangJiang Sillago sihama group, the polymorphism proportion is 39.88%. The results show that the 14 pairs of primers fit to analysis the population resources of Sillago sihama by AFLP.2. For polygenetic relationship among Sillago sihama, genetic distances were calculated and used for constructing a dendragram by UPGMA clustering analysis. The results suggest that the relationship of ZhanJiang and YangJiang is more approximation, HaiNan and YangJiang is farthest. The similarity coefficient is between 0.1911 to 0.7087 in HaiNan and 0.0767 to 0.7010 in ShanWei , while the coefficience is between 0.1071 to 0.6453 in ZhanJiang and 0.1877 to 0.6141 in YangJiang. This means that the YangJiang has the most similarity meanwhile the HaiNan has the most abundance genetic diversity.3. Analyzing genetic variation among populations , We found that the genetic diversity among populations is 0.3107 , genetic diversity within populations is 0.1102 . This results show a great genetic differentiation among populations. While the genetic diversity indexs with populations is 0.6454 . AMVOA analysis indicated there are 78% genetic variation caused by different populations. Diversity indexs and AMVOA analysis all show genetic variation main caused by populations.4. Four sillago sihama populations genetic similarity distribute in 0.5324-0.9472, mean is 0.7006; Shannon index distribute in 0.1378-0.2191, mean is 0.1748. The results show that genetic diversity of sillago sihama is in a lower condition. Moreover, the clustering analysis in UM shows, that was 4 different geographic populations were divided into three groups, SW and HN populations clustered into one group,ZJ and YJ in one group; the farthest genetic distance is between HN and ZJ, the lest is between ZJ and YJ.