引起山西省小麦纹枯病的丝核菌融合群鉴定及其对不同杀菌剂的敏感性  

Identification of anastomosis groups and evaluation of fungicide sensitivity of soilborne fungus Rhizoctonia isolates causing wheat sharp eyespot in Shanxi Province

作　　者：史晓晶 王华杰 雷慧 赵丽娟 Shi Xiaojing;Wang Huajie;Lei Hui;Zhao Lijuan(Department of Biology,Xinzhou Normal University,Xinzhou 034000,Shanxi Province,China;Xinzhou Administration for Market Regulation,Xinzhou 034000,Shanxi Province,China)

机构地区：[1]忻州师范学院生物系,山西忻州034000 [2]忻州市市场监督管理局,山西忻州034000

出　　处：《植物保护学报》2022年第6期1593-1601,共9页Journal of Plant Protection

基　　金：山西省基础研究计划(20210302124623);山西省高等学校科技创新项目(2021L464);山西省忻州市科技计划应用基础项目(20210104)。

摘　　要：为明确引起山西省小麦纹枯病的丝核菌Rhizoctonia种类及其对杀菌剂的敏感性,通过形态学特征观察、rDNA ITS序列分析及致病性测定鉴定分离自23个麦区小麦病样的195株纹枯病菌,并采用菌丝生长速率法测定菌株对氟酰胺、噻呋酰胺和己唑醇的敏感性。结果显示,所有菌株的菌落形态接近于丝核菌,呈双核,可与融合群(anastomosis group,AG)D组各亚群菌株菌丝发生融合反应,但在系统发育树中全部与AG-DI亚群菌株聚为一支,表明195株菌株均为禾谷丝核菌R.cerealis AG-DI亚群,且经致病性试验验证这些菌株均为山西省小麦纹枯病的病原菌。氟酰胺、噻呋酰胺和己唑醇对菌株的EC_(50)范围分别为0.092~0.610、0.067~0.142和0.008~0.111μg/mL,均值分别为0.331、0.074和0.052μg/mL,且菌株对氟酰胺、噻呋酰胺和己唑醇的敏感性频率分布均呈连续的单峰曲线,因此可将以上均值作为山西省小麦纹枯病病原菌禾谷丝核菌AG-DI亚群对氟酰胺、噻呋酰胺和己唑醇的敏感基线。To clarify the etiology of wheat sharp eyespot and the fungicide sensitivity of the pathogen,195 Rhizoctonia isolates,obtained from wheat sheath with sharp eyespot symptoms collected from23 wheat-grown areas in Shanxi Province,were identified based on morphological traits,phylogenetic analyses of rDNA ITS,and pathogenicity test.Meanwhile,EC_(50)values of all the isolates were determined by mycelial growth rate method for flutolanil,thifluzamide,and hexaconazole.The results showed that the colonies of all the isolates with two nuclei in each hyphal cell were similar with Rhizoctonia spp.,and these isolates were placed in anastomosis group(AG)D in hyphal fusion tests.All the isolates were clustered in the same clade with AG-DI isolates in phylogenetic tree.Therefore,all the195 isolates were identified as Rhizoctonia cerealis AG-DI which was regarded as the causal agent of wheat sharp eyespot in Shanxi Province.The EC_(50)ranges of flutolanil,thifluzamide,and hexaconazole were 0.092-0.610,0.067-0.142,and 0.008-0.111μg/mL,respectively,among these isolates,with a mean EC_(50)of 0.331,0.074,and 0.052μg/mL,respectively.The sensitivity frequencies were all continuous unimodal curves for all the three fungicides.These mean EC_(50)could be used as the sensitivity baselines of flutolanil,thifluzamide,and hexaconazole for R.cerealis AG-DI causing wheat sharp eyespot in Shanxi Province.

关 键 词：小麦纹枯病 禾谷丝核菌AG-DI 氟酰胺 噻呋酰胺 己唑醇 

分 类 号：S435.121.4[农业科学—农业昆虫与害虫防治]