摘要
甲基硫菌灵、戊唑醇、咪鲜胺和苯醚甲环唑4种杀菌剂用于防治山核桃干腐病多年,为明确山核桃干腐病菌Botryosphaeria dothidea对其抗性发展现状,指导山核桃干腐病防治的精准用药,采用区分剂量法测定了山核桃干腐病菌对甲基硫菌灵、戊唑醇、咪鲜胺和苯醚甲环唑的抗性频率以及部分菌株对上述药剂的敏感性(EC_(50)),评价了甲基硫菌灵抗性菌株和敏感菌株在菌丝生长速率、产分生孢子器数量和致病力等方面的差异,分析了抗性菌株对甲基硫菌灵的抗性分子机制。结果表明:山核桃干腐病菌对甲基硫菌灵已经表现出严重抗性,抗性频率达到84.37%。随机选择4株敏感菌株的平均EC_(50)值为0.263μg/mL,而5株抗性菌株的相对抗性水平在49.9~84.8之间。供试所有菌株对戊唑醇、咪鲜胺和苯醚甲环唑均表现敏感。戊唑醇、咪鲜胺和苯醚甲环唑对随机选取的6个菌株的平均EC_(50)值分别为0.148、0.023和0.091μg/mL。在适合度方面,甲基硫菌灵敏感菌株的菌丝生长速率显著高于抗性菌株,产分生孢子器数量显著少于抗性菌株;在致病力方面,甲基硫菌灵敏感菌株与抗性菌株无显著差异。在甲基硫菌灵抗性菌株的β-tubulin序列中,未发现与苯并咪唑类杀菌剂抗性有关的氨基酸突变。
Thiophanate-methyl,tebuconazole,prochloraz,and difenoconazole have been adopted for many years for the control of hickory canker(Botryosphaeria dothidea).In order to understand the resistance status and guide the prevention and control of hickory canker,the resistance frequencies of B.dothidea to the four fungicides were detected with the discrimination dose assay.EC_(50) values of the four fungicides to some isolates were also investigated.The fitness differences in mycelial growth rate,number of pycnidia,and pathogenicity between thiophanate-methyl resistant isolates and sensitive ones were determined.The resistance mechanism of thiophanate-methyl resistant isolate was also analyzed.The results showed that most B.dothidea isolates have developed resistance to thiophanate-methyl with a resistance frequency of 84.37%.The average EC_(50) value of thiophanate-methyl against the four sensitive B.dothidea isolates randomly chosen was 0.263μg/mL and the relative resistance levels of five resistant isolates were between 49.9-84.8.All the tested isolates were sensitive to tebuconazole,prochloraz,and difenoconazole.The average EC_(50) values of tebuconazole,prochloraz,and difenoconazole against six B.dothidea isolates chosen at random were 0.148,0.023,and 0.091μg/mL,respectively.In terms of fitness penalty,no significant difference in pathogenicity was detected between thiophanate-methyl resistant isolates and sensitive ones.However,the mycelial growth rates of the sensitive isolates were significantly faster than that of the resistant isolates,while the number of pycnidia of the sensitive isolates was significantly less than that of the resistant isolates.No mutations of amino acids related to benzimidazole resistance were detected inβ-tubulin from isolates resistant to thiophanate-methyl.
作者
施心成
李涛
张传清
SHI Xincheng;LI Tao;ZHANG Chuanqing(College of Advanced Agricultural Sciences,Zhejiang Agricultural and Forestry University,Hangzhou 311300,China)
出处
《农药学学报》
CAS
CSCD
北大核心
2023年第6期1288-1294,共7页
Chinese Journal of Pesticide Science
基金
浙江省重点研发项目(2020C02005)。
