摘要
[目的]明确广西百色市乐业县芒果蒂腐病的病原菌种类,并探究杀菌剂对病原菌的室内抑菌效果,以期为芒果蒂腐病的田间防治提供理论依据.[方法]采用组织分离法对采集自广西百色市乐业县幼平乡百安村芒果种植区具有蒂腐病典型症状的芒果进行潜在病原菌分离和纯化,利用柯赫氏法则对潜在病原菌进行致病性测定,结合病原菌的形态学特征及ITS、β-tubulin和EF-1α序列分析及系统发育树进化分析鉴定病原菌种类.选取21种常用杀菌剂对病原菌进行室内毒力测定.[结果]通过传统真菌形态学、生物学分类鉴定及ITS、β-tubulin和EF-1α序列分析相结合的方法确定引起芒果蒂腐病的病原菌为葡萄座腔菌(Botryosphaeria dothidea).杀菌剂对病原菌菌丝生长抑制作用测定结果显示,50%多菌灵、400 g/L氟硅唑、40%菌核净、250 g/L吡唑醚菌酯、430 g/L戊唑醇和450 g/L咪鲜胺的抑菌效果较好,其次是5%香芹酚、80%代森锰锌和20%春雷霉素,23.40%双炔酰菌胺、350 g/L精·甲霜灵和30%氟吗啉的抑菌效果最差.室内毒力测定结果显示,供试21种杀菌剂中对病原菌抑制效果较好的是50%多菌灵、250 g/L吡唑醚菌酯和400 g/L氟硅唑,3者的抑制中浓度(EC50)均小于0.1000 mg/L,其次是430 g/L戊唑醇、450 g/L咪鲜胺、10%苯醚甲环唑、40%菌核净和240 g/L噻呋酰胺,EC50介于0.1000～1.0000 mg/L,抑菌效果较差的是23.4%双炔酰菌胺、350 g/L精·甲霜灵、8%宁南霉素和30%氟吗啉,EC50均高于100.0000 mg/L.[结论]引起广西百色市乐业县芒果蒂腐病的病原菌为葡萄座腔菌.50%多菌灵、250 g/L吡唑醚菌酯和400 g/L氟硅唑对葡萄座腔菌的抑制效果最好,可作为进一步田间试验的首选药剂;430 g/L戊唑醇、450 g/L咪鲜胺、10%苯醚甲环唑、40%菌核净和240 g/L噻呋酰胺可作为备选药剂;8%宁南霉素、350 g/L精·甲霜灵、23.4%双炔酰菌胺和30%氟吗啉的抑菌效果较差,不推荐作为后续试验及防治工作使用药剂.
Abstract
[Objective]This study aimed to identify the fungal pathogen responsible for stem-end rot in mangoes in Leye County,Baise City,within the Guangxi Zhuang Autonomous Region,and assess the efficacy of various fungicides against the pathogen in controlled conditions.This study provides a scientific basis for the field management of mango stem-end rot.[Methods]Mangoes exhibiting typical symptoms of stem-end rot were collected from Baian Village,Youping Township,Leye County,Baise City.The isolation and purification of potential pathogenic fungi from these samples were carried out,followed by pathogenicity tests using Koch's method.The pathogens were identified based on morphological characterization,and genetic analyses involving ITS,β-tubulin and EF-1α gene sequences,and phylogenetic relation-ships.Additionally,twenty-one commonly used fungicides were evaluated for their efficacy against the identified patho-gen in vitro.[Results]The fungal agent of mango stem-end rot was identified as Botryosphaeria dothidea,utilizing a com-bination of traditional fungal morphology,taxonomic classification,and molecular analyses(ITS,β-tubulin and EF-1α sequence).In vitro,testing revealed that all 21 tested fungicides inhibited the mycelial growth of the pathogen to varying degrees.The most effective fungicides were 50%carbendazim,400 g/L flusilazole,40%dimethachlon,250 g/L pyraclos-trobin,430 g/L tebuconazole,and 450 g/L prochloraz,followed by 5%carvacrol,80%mancozeb,and 20%kasugamy-cin.Conversely,23.4%mandipropamid,350 g/L metalaxyl·m,and 30%flumorph displayed the least efficacy.Fungi-cides with an EC50 value of less than 0.1000 mg/L,indicating superior inhibitory effects,included 50%carbendazim,250 g/L pyraclostrobin,and 400 g/L flusilazole.Those with EC50 values ranging from 0.1000 mg/L to 1.0000 mg/L,such as 430 g/L tebuconazole,450 g/L prochloraz,10%difenoconazole,40%dimethachlon,and 240 g/L thifluzamide,were also effective but to a lesser extent.The efficacy of 23.4%mandipropamid,350 g/L metalaxyl·m,8%ningnanmycin,and 30%flumorph was notably lower,with EC50 values exceeding 100.000 mg/L.[Conclusion]The pathogen responsible for mango stem-end rot in Leye County,Baise City,is B.dothidea.Fungicides such as 50%carbendazim,250 g/L pyraclos-trobin,and 400 g/L flusilazole demonstrated the highest efficacy against B.dothidea and are recommended in the field trials as primary treatment options.Alternatively,430 g/L tebuconazole,450 g/L prochloraz,10%difenoconazole,40%dimethachlon,and 240 g/L thifluzamide could serve as secondary agents.However,fungicides like 8%ningnanmycin,350 g/L metalaxyl·m,23.4%mandipropamid,and 30%flumorph,which exhibited poor bacteriostatic effects,are not recommended for further testing or control measures.
基金项目
广西科技基地和人才专项(桂科AA21196003)
贵州大学实验室开放项目(SYSKF2023-093)
贵州大学创新创业训练计划项目(贵大校创字2022085号)
贵州大学SRT计划(Guike AA21196003)
国家科技期刊平台
NSTL
万方数据