福建和安徽茶树轮斑病菌的鉴定及对3种杀菌剂的敏感性

Identification of pathogen causing gray blight on Camellia sinensis from Fujian and Anhui provinces and their sensitivity to three fungicides

2017—2021年从福建和安徽茶区采集茶树轮斑病叶,利用组织分离法分离纯化菌株,通过形态学特征、多位点序列分析和柯赫氏法则对病原菌进行鉴定。结果发现分离获得的40株菌株的菌落形态特征不同,共存在4种类型;分生孢子形态特征相似,均为纺锤形、直或稍弯曲、中间3个细胞褐色,两端细胞透明。进一步对代表性菌株进行ITS、TUB2和TEF基因的PCR扩增、测序和序列分析,将测试菌株分别鉴定为茶假拟盘多毛孢Pseudopestalotiopsis camelliae-sinensis和山茶假拟盘多毛孢Ps.chinensis,其中由Ps.chinensis引致的茶树轮斑病在福建茶区为首次报道。利用菌丝生长速率法测试了不同来源的茶树轮斑病菌对3种常用杀菌剂的敏感性,结果表明测试菌株对苯醚甲环唑的敏感性均较高,EC50值分布在0.0350~0.2675μg·mL^(-1);其次为戊唑醇和多菌灵,EC50值分布在0.1263~1.5826μg·mL^(-1)。在生产实践中可应用苯醚甲环唑和戊唑醇作为防治茶树轮斑病的优选药剂。

From 2017 to 2021,diseased leaves of gray blight on Camellia sinensis were collected from tea plants in Fujian and Anhui provinces,and the pathogens of tea gray blight were obtained and identified by mor-phology characteristics,multi-loci sequence analysis and Koch’s postulate test.The results indicated that a total of 40 isolates showed four types in colony morphology.The conidia were similar,and they were spindle shaped,straight or slightly curved,with three brown cells in the middle and transparent cells at both ends.Based on the PCR amplification,sequencing and multi-loci sequence analysis of ITS,TUB2 and TEF genes for representative isolates,they were identified as Pseudopestalotiopsis camelliae-sinensis and Ps.chinensis,respectively.This was the first report of Ps.chinensis causing gray blight on C.sinensis in Fujian Province.Furthermore,it was deter-mined for the sensitivity of the pathogen to three fungicides in this study.The results showed that the tested iso-lates had the highest sensitivity to difenoconazole,with an EC50 value of 0.0350-0.2675μg·mL^(-1),followed by tebuconazole and carbendazim,with an EC50 value of 0.1263^(-1).5826μg·mL^(-1).In conclusion,difenoconazole and tebuconazole can be selected as the priority to control gray blight disease of C.sinensis.