ISSR Analysis of Genetic Relationship of Walnut (Juglans regia L.) Species in Xinjiang

【Objective】To analyse the genetic relationship of walnuts at DNA level by ISSR technique.The findings of this research would provide theoretic evidence for the protection of walnut resources,its development and utilization and selective breeding of new varieties.【Method】ISSR analysis of samples was conducted with new-born leaf as material,8 ISSR primers were screened and conducted PCR amplification for 24 DNA.The genetic similarity(GS) of the samples were calculated by NTSYSpc2.1 software,and UPGMA cluster analysis was conducted.【Result】The results showed that 86 loci were detected with the 8 primers,among which there were 60 polymorphic loci,the samples have polymorphic ratio of 70.00%.The genetic similarity(GS) among 24 walnuts ranged from 0.29 to 0.93.When GS was 0.37,cultivated walnut species and other nature walnut species could be clustered into two groups.【Conclusion】The study showed that the walnuts tested had high polymorphism,with apparent gene differentiation among samples,relatively far genetic relationship and obvious regional features.