Analysis on Genetic Relationships among 8 Main Pear Cultivars in Yunnan Province Based on ISSR Molecular Markers

[Objective]The research aimed to discuss the feasibility of classification and systematical development of pear cultivars by ISSR.[Method] The Inter-simple sequence repeat(ISSR) molecular markers were used to analyze the genetic relationship of 8 main pear cultivars in Yunnan Province.[Result]The results of optimal experiment showed that 1×PCR buffer,100 μmol/L dNTP,0.3 μmol/L primer,20 ng template DNA and 1.5 U Taq DNA polymerase in a total volume of 20 μl were suitable for ISSR-PCR amplification system of pear cultivars in Yunnan Province,9 primers were screened from 24 random primers.A total number of 135 bands were amplified,among which 102 were polymorphic.The polymorphic ratio was 75.5%.The genetic similarity coefficients among 8 pear cultivars were between 0.186 and 0.750,and the average genetic similarity coefficient was 0.476.The clustering analysis conducted with UPGMA indicated that 8 main pear cultivars in Yunnan Province could be classified into 2 groups.Ribenshuijingli,Zao95-2,Sichuanhuoba and Xizilu made up of the first group,and Zaosu,Jinhua,Zaohuangsu and Dangshanli constituted the second group.This accorded with previous results made by traditional morphological study.[Conclusion]The study will provide the reference for utilization and new variety selection of pear resources.