ISSR analysis of genetic diversity of Juglans mandshurica Maxim populations

In order to investigate genetic diversity of Juglans mandshurica Maxim resources,genetic diversity of 180 individuals among six J.mandshurica Maxim populations from centralized distribution areas were researched appling Inter-simple sequence repeat(ISSR) molecular technique.Through screening from 50 primers,14 ones were selected out.120 polymorphic loci were detected from total 140 loci,and the total percentage of polymorphic band was 85.71%.At species level Shannon's information index and Nei's gene diversity index of J.mandshurica Maxim was 0.452 1 and 0.302 4,respectively,and it indicated that the genetic diversity at species level relatively high;while at population level,the genetic diversity was unimodal along the latitude from south to north,that of Laoyeling was the highest and Sanhe was the lowest.Results of AMOVA analysis demonstrated that the within-population component had a high degree which accounted for 81.83% of the total variation,while the among-population component accounted for 18.17%.The coefficient of gene differentiation among populations was 0.161 8 based on Nei's genetic diversity index and pairwise genetic distance among populations ranged from 0.047 0 to 0.122 5.In addition,results of UPGMA clustering analysis showed that the populations that clustered together in genetic was near in geographical,according with distribution of physical geography.The mainly reason for preservation of J.mandshurica Maxim was not genetic variations but cutting,habitat destruction and degradation.