杧果蒂腐病菌对多菌灵的抗药性测定及其杀菌剂筛选

对来自海南3个地区的86个杧果蒂腐病菌(Botryodiplodia theobromae Pat.)菌株进行了对多菌灵的抗药性测定,结果表明,杧果蒂腐病菌群体中存在着对多菌灵抗性的群体。采用生长速率法进行了23种杀菌剂对4株杧果蒂腐病菌的室内毒力测定,通过EC50值、EC90值及与多菌灵的交互抗性等的综合分析,结果表明,作为防治杧果蒂腐病的首选药剂有咪鲜胺锰盐、丙环唑、氟硅唑、咪鲜胺、异菌脲、苯醚甲环唑、戊唑醇、腈菌唑、吡唑醚菌酯和井冈霉素10种杀菌剂,可选杀菌剂还有百菌清和代森锰锌。杧果蒂腐病菌除对多菌灵产生抗性外,还对甲基硫菌灵、醚菌酯和烯唑醇3种杀菌剂产生了抗药性。通过交互抗性分析,多菌灵、甲基硫菌灵和烯唑醇3种杀菌剂之间存在交互抗性,而醚菌酯与井冈霉素之间存在负交互抗性。为了避免杧果蒂腐病菌对某种杀菌剂产生抗药性,建议上述可选用杀菌剂交替使用。

Resistance of Botryodiplodia theobromae to carbendazim and the fungicides screening using stem end rot of mango fruit as a control

The resistance to carbendazim of 86 isolates of mango stem end rot pathogen Botryodiplodia theobromae Pat.collected from 3 regions in Hainan province was tested in vitro.The toxicity of 23 fungicides to 4 isolates of B.theobromae was tested by mycelium growth rate methods.The toxicity results were analyzed by the EC50 value,the EC90 value and the crossresistance to each other.Results showed that 10 fungicides including sporgon,propiconazole,flusilazole,prochloraz,iprodione,difenoconazole,tebuconazole,myclobutanil, pyraclostrobin and validamycin A were recommended for choices for controlling mango stem end rot disease.In addition,the fungicides of chlorothalonil and mancozeb could also be chosen.The re-sistance to thiophanate-methyl,kresoxim-methyl,and diniconazole was appeared in the tested pathogens.In cross-resistance test, the results showed that carbendazim,kresoxim-methyl and diniconazole had cross-resistance each other,while kresoxim-methyl and validamycin A had negative cross-resistance each other.To avoid the resistance of the pathogen to some of the fungicides,such fungicides should be used by turns.