Genetic Diversity Of The Wild And Raised Elopichtys Bambusa Population From Dnajiangkou Reservoir Revealed By Issr Markers

The large ferocious, Elopichtys bambusa, was considered a slap-up fish species. Understanding thegenetic structure and the levels of genetic diversity of E. bambusa has important meaning for the evaluation,protection and reasonable utilization of its resource. In this study, the ISSR (Inter Simple Sequence Repeat)technique was applied to investigate the genetic diversity of the wild population and raised population of E.bambusa from Danjiangkou Reservoir. The main result shows as follows:(1) The orthogonal design was used to optimize ISSR-PCR system of E. bambusa in five factors(Mg2+, primer, dNTPs, DNA template and Taq DNA polymerase) respectively. The optimized ISSR-PCRsystem(25μl) was established as follows: Mg2+2.0mM, primer0.4μM, dNTPs0.2mM, DNA template100ng(25μl) and Taq polymerase1.0U. Then, based on the optimal ISSR-PCR system, annealing at52℃and35cycles were determined.(2) Eighteen ISSR primers were screened to amplify genomic DNA of the wild population and raisedpopulation of E. bambusa(totaled60individuals). Totally148reproducible DNA fragment ranging from200to2500bp were amplified from all the60individuals. The polymorphic locus were58, and thepercentage of polymorphic loci was39.19%. Using POPGENE software estimated the genetic diversityparameters. The percentages of polymorphic loci(PPB) in two populations of E. bambusa were29.05%and27.70%. The observed numbers of alleles(Na) were1.2905and1.2770. The effective numbers of alleles(Ne)varied were1.1489and1.1490. The Nei’s gene diversities(h) were0.0906and0.0901. The Shannon’sinformation indices(I) were0.1388and0.1372. The genetic distances were0.1031and0.1079. The resultsshowed that the wild population had a higher level of genetic diversity.(3) Using Shannon indices analyzed differentiation of E. bambusa. The result showed that76.46%from intra-populations, and23.54%from inter-populations. An analysis of the molecularvariation(AMOVA) demonstrated that55.51%of variance from intra-populations and44.49%frominter-populations. The two results showed that the most variance were from within population and lesservariance among populations. The analysis of Nei’s gene diversity revealed the coefficient of geneticdifferentiation(Gst) among-populations of E. bambus was0.3608and the Φ-statistics(Φst) was0.4449according to AMOVA. The two results showed that there was strong genetic differentiation among-population of E. bambus. The gene flow(Nm) was1.1297within-population, and the level of geneflow is high.