四川地区藜麦叶斑病病原菌的分离及鉴定

Isolation and identification of leaf spot disease pathogen of Chenopodium quinoa in Sichuan

通过筛查并鉴定四川地区藜麦叶斑病的致病菌,旨在为后续研发生物防治制剂提供理论依据。分别采集成都金堂、十陵和西昌等种植基地患有藜麦叶斑病的植株。经组织分离、平板纯化分离菌株,并采用科赫法则确定致病菌;扩大培养致病菌菌株,提取其DNA,用rDNA-ITS(rDNA-内转录间隔区)、16S rDNA通用引物进行PCR扩增测序,对测序结果进行BLAST比对,并用MEGA 4.0构建系统发育树。结果显示,分离筛选到的2株细菌菌株SCCDP-2、SCCDP-4能够导致四川地区藜麦叶斑病的发生,经鉴定为成团泛菌(Pantoea agglomerans)。

The pathogenic bacteria of Chenopodium quinoa leaf spot disease in Sichuan were screened and identified to provide theoretical basis for subsequent development of biological control agents.The plants infected with C.quinoa leaf spot disease were collected from Jintang,Shiling and Xichang planting bases in Chengdu.The strains were isolated by tissue isolation and plate purification,and the pathogenic bacteria were determined according to Koch’s postulates.The pathogenic strains were further cultivated,and its DNA was extracted.The universal primers of rDNA-ITS and 16S rDNA were used for PCR amplification and sequencing,and the sequencing results were compared by BLAST.In addition,MEGA 4.0 was used to build phylogenetic trees.The results showed that the isolated and screened two strains SCCDP-2 and SCCDP-4 could cause the occurrence of C.quinoa leaf spot disease in Sichuan,and the two strains were identified as Pantoea agglomerans.