廖映凯　罗吉　许芮涵　芶琳　邱爱东

摘要： 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-內转录间隔区）、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）。

关键词： 藜麦叶斑病;病原菌;鉴定

中图分类号： S432.4+2 文献标识码： A 文章编号： 1000-4440（2021）01-0060-07

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

LIAO Ying-kai1， LUO Ji1， XU Rui-han1， GOU Lin2， QIU Ai-dong1

（1.School of Pharmacy and Bioengineering， Chengdu University， Chengdu 610106， China;2.College of Life Science， Sichuan Agricultural University， Chengdu 611130， China）

Abstract： 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 Kochs 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.

Key words： leaf spot disease of Chenopodium quinoa;pathogenic bacteria;identification

藜麦（Chenopodium quinoa）是藜科藜属植物，原产于南美洲的安第斯山高原地区，具有5 000～7 000年的种植历史[1]。藜麦具有很高的营养价值，被联合国粮食及农业组织推荐为适宜人类食用的“全营养食品”，其蛋白质含量显著高于水稻和玉米，达到16%～30%，此外，藜麦的必需氨基酸比例较均衡，并且极易被人体吸收[2-4]。20世纪80年代末，藜麦被引入中国西藏地区进行试种研究，2008年以后开始得到大规模引种[5]。随着种植规模的扩大，藜麦病害愈发突显，从而严重影响了其产量，尤其在四川地区，藜麦叶斑病的发病率约为40%，在严重的地块甚至达到80%。患病藜麦叶片上出现坏死病灶，呈斑点状，中间浅黄色，边缘褐色，外围有褪绿晕圈，严重时可导致藜麦死亡。本研究对四川地区藜麦叶斑病患病植株进行采样及病原菌分离，根据形态学特征并结合rDNA-ITS（rDNA-内转录间隔区）、16S rDNA序列分析，对藜麦叶斑病致病菌进行系统鉴定，以期为藜麦叶斑病的后续生物防治提供理论依据。……