辽宁省辣椒土传病害镰刀菌鉴定及rDNA-ITS序列分析

［目的］ 对分离的辣椒镰刀菌形态、基因序列进行研究，以确定病原菌的种类及这些菌的同源性，为进一步开展该病害诊断和防治研究奠定基础。［方法］ 对采自辽宁省各地辣椒土传病害的16株病菌进行形态观察及rDNA-ITS序列分析。［结果］ 引起辽宁省辣椒土传病害的主要镰刀菌有尖镰孢、茄镰孢、锐顶镰孢和串珠镰孢等4种，根据菌株分生孢子形态和rDNA ITS序列同源性，将ZW13、LY3、PJLJ、HC5、CY2、CY5、TLLJ、LY5、LY1菌株聚类为尖镰孢；FSLJ2和FSLJ3菌株聚类为茄镰孢；ZW和ZW18菌株聚类为锐顶镰孢；KPLJ、LZLJ、FSLJ1菌株聚类为串珠镰孢。［结论］ 从分子系统树和菌株间的遗传距离看出镰刀菌同种同源性都很高，不同种之间同源性相对较低，种间遗传差异较大。

Identification of phytopathogenic Fusarium causing pepper soil borne diseases in Liaoning Province and sequence analysis of ribosomal DNA-ITS

［Objective］ The morphology of Fusarium strains isolated from pepper and their gene sequences were compared and analyzed to identify the pathogen causing pepper soil borne diseases,and understand their homology,so as to provide the basis for disease diagnosis and control.［Method］ Morphological observation and sequence analysis of ribosomal DNA-ITS of 16 strains, collected from Liaoning Province, were made.［Result］ The main pathogens of soil borne diseases in pepper production of Liaoning were Fusarium oxysporum，F. solani，F. acuminatum and F. moniliforme. According to their conidium morphology and ribosomal DNA-ITS homology, ZW13, LY3, PJLJ, HC5, CY2, CY5, TLLJ, LY5 and LY1 strains were clustered as F. oxysporum, FSLJ3 and FSLJ2 as F. solani, ZW and ZW18 as F. acuminatum, and KPLJ, LZLJ and FSLJ1 as F.moniliforme. ［Conclusion］ Molecular phylogenetic tree and genetic distances between the strains showed that the same species of Fusarium had higher homology and different species had lower homology, suggesting that the inter pecies genetic diversity was greater.