辽宁省辣椒疫病菌多态性及致病力分化研究初探

Preliminary study on polymorphism and pathogenicity of Phytophthora capsici Leonian in Liaoning

摘要:

【目的】明确辽宁省辣椒疫病菌多态性及致病力分化与区域性关系。【方法】利用SRAP技术对辽宁省25个辣椒疫病菌菌株进行了PCR扩增及NTSYS-PC聚类分析, 用灌根法进行致病力分化试验并对试验结果进行SPSS 11.5分层聚类分析。【结果】利用筛选出的27组引物对25个菌株进行扩增, 得到578条条带, 每对引物多态性比率在84%?100%之间, 多态性丰富; 供试菌株间遗传相似性较高, 相似系数0.56?0.91, 以相似系数0.68为阈值划分, 25个菌株可聚为4组。试验菌株80%为中等致病力, 聚类结果较为分散。【结论】供试菌株没有表现出明显的区域性特征, 菌株致病力强弱分化区域特征性规律不明显。

关键词:辣椒疫病菌, SRAP技术, 多态性, 致病力

Abstract:

[Objective] The definite relation was found between polymorphism, pathogenicity differentiation of Phytophthora capsici Leonian and regionality in Liaoning Province. [Methods] Using Sequence related Amplified Polymorphism (SRAP) technology, the 25 strains of Phytophthora capsici Leonian in Liaoning were amplified in PCR method and evaluated by clustering analyses of NTSYS-PC. The pathogenic differentiation was researched by root-drenching method, and it was examined with hierarchical cluster combination by SPSS 11.5. [Results] The results showed that the DNA of 25 strains were amplified by 27 primer pairs. A total of 578 bands were identified, of which 548 bands were polymorphic. The percentages of polymorphic fragments of each primer pairs were ranged from 84% to 100%. There were abundant polymorphism clustering analysis showed that the genetic similarity among the 25 strains of Phytophthora capsici Leonian were very high. The similarity coefficients varied from 0.56 to 0.91. They were divided into four groups at 0.68 for similarity coefficient, significant correlations were not obvious among the sources of these strains, and there were not regional characteristics. 80% strains were intermediate pathogenicity. [Conclusion] The tested strains were not significantly regional characteristics, and there was no regularity of pathogenicity differentiation from different areas.

Key words:Phytophthora capsici Leonian, SRAP technology, Polymorphism, Pathogenicity