Study On The Genetic Diversity Of Castanopsis Fissa

A rapid, convenient, credible molecular marker——ISSR was used in studingthe genetic diversity of six populations of Castanopsis fissa in Guangxi. Theresults showed as follows:1. Compared of the appearance, quantity, purity and electrophoresis patternof total DNA of Castanopsis fissa extracted by two methods, the result showedthat the improved CTAB method was better than the silica beads absorptionmethod in extracting total DNA of Castanopsisfissa.2. The optimal ISSR reaction system suitable for Castanopsis fissa wasfounded, which was: 20μL reaction volume containing 60 ng template DNA,2.0μL 10×buffer, 0.3μmol/L primer, 0.25μmol/L dNTP, 1U Taq polymerase.Amplification program was: pre-denature at 94℃for 5 min, denature at 94℃for 45 s, annealing at 51.2 to 54℃for 45 s, extension at 72℃for 1.5 min, 45cycles, fully extension at 72 for 7 min, preservation at 4℃.3.11 legible, polymorphic primers from 100 primers were used in the ISSRreaction of Castanopsisfissa. They were 810, 811,834, 836, 840, 841,842, 843,844, 857 and 864. 4. Genetic diversity and genetic structure of six Castanopsis fissapopulations of LB, GJ, LC, GT, TD and TZ (30 samples for each population)were studied by ISSR molecular marker. 11 ISSR primers generated 151 legiblebands, of which 132 were polymorphic, the percentage of polymorphic bandswas 78.12%. Analysis by POPGENE(version 1.31), it indicated that the geneticdiversity of GJ was highest(PPB=68.87,He=0.2216, J=0.3333). Analysis ofgenetic structure for populations showed that there was 81.54% diversity withinpopulations, and 18.46% among populations. Based on UPGMA cluster analysis,it indicated that six populations were divided into two embranchments. Thegenetic relationship between LB and GJ was the nearest, they clustered firstly,followed with LC. The three populations above formed an embranchment. Foranother embranchment, GT and TD clustered firstly, followed with TZ.5. The strategies of conservation and utilization of Castanopsis fissaresource in Guangxi were brought out.