8个云南主要栽培梨品种亲缘关系的ISSR分析

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

[目的]探索利用简单序列重复间区（ISSR）分子标记研究供试栽培梨品种的分类和系统发育。[方法]利用ISSR分子标记技术对8种云南主要栽培梨品种的亲缘关系进行分析。[结果]ISSR—PCR反应体系优化结果表明，20μl ISSR．PCR反应体系中各因素的最佳浓度分别为：1×PCR buffer、100μmol／L dNTP、0．3μmol／L引物、20ng的模板DNA和1．5U Taq DNA聚合酶，并在此基础上建立了梨ISSR—PCR反应体系。从24个引物中筛选出9个能扩增出清晰带并具多态性的引物，共扩增出了135条DNA片段，其中102个DNA片段呈现多态性，占总扩增片段的75．5％。利用NTSYS—pc2．10t软件计算8种梨品种间的Jaccard遗传相似系数。结果显示梨品种间的相似性系数为0．186～0．750，平均遗传相似性系数为0．476。UPGMA聚类分析表明，8种梨品种可以聚为2类：第一类群包括日本水晶梨、早95-2、四川火把和西子绿；第二类群由早酥、金花、旱黄酥和砀山梨4个品种组成，这与传统分类结果一致。[结论]该研究为梨资源的开发利用及新品种的选育提供科学依据。

[ 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 cuhivars in Yunnan Province. [ Result] The results of optimal experiment showed that 1 x 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 20μl 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 cuhivars 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.