Cultured Population Genetic Diversity And Molecular Detection Of Channel Catfish (Ictalurus Punctaatus) In Jiangxi

Four cultured populations of channel catfish (Ictalurus punctatus) have been collected in Jiangxi province total 72 individuals for research the genetic diversity by means of AFLP, then the important polymorphisms fragments have been cloned and sequenced and homology analyzed.The results and conclusions showed as follows:1. There are 20 primer combinations have been screened from the 64 primer combinations of EcoRI+3/MseI+3, whose strips are clearly and polymorphisms are fine. A total of 179 loci were amplified by four primer combinations whose polymorphisms information contents are richer than others, and 109 were polymorphism loci took up 60.89%of the total number. Primer combination E4/M7(E-ACG/M-CAA) is the best whose percentage of polymorphism is 66.67%.2. The coefficient of gene differentiation was 0.1314, showing a certain extent of genetic differentiation among the four populations of channel catfish in Jiangxi province. The Shannon information indices are almost same, and the average value was 0.2910 which explained that the genetic variation mainly happened within populations. The analysis of molecular variance AMOVA analysis indicated that the variance among populations was 9.02%and 90.98%within populations. Moreover, clustering analysis also indicated that the four populations of genetic differentiation mainly produced within populations.3. There is inadequate obvious differentiation of channel catfish in different nurseries of Jiangxi province and just one big population divided into some small populations.4. After cloning and sequencing to the fragments of polymorphism,14 sequences were submitted in NCBI with the size of 56-248 bp and obtained serial numbers. It find that the 14 homologous sequences are related to lots of genes such as immunity and own protection relevant genes, growth and development relevant genes, energy and signal conduction relevant genes and protein synthesis relevant genes. By comprehensive analysis, the polymorphism sequence JXE3M8aflp4 and JXE3M8aflp6 can be determined the molecular markers of excellent characters.