化学杀菌剂对木霉菌厚垣孢子萌发及菌丝生长的抑制作用

摘要

For exploring the influences of application and residue of chemical fungi-cides on chlamydospore preparations of Trichoderma spp., the effects of seven chemical fungicides on chlamydospore germination and mycelia growth of two bio-control fungi T. harzianum 610 and T. longibrachiatum 758 were studied. Carben-dazim, tebuconazole and difenoconazole showed strong toxicities, thiram and car-boxin showed moderate toxicities, pentachloronitrobenzene and metalaxyl showed weak toxicities to the tested two strains. Mycelia growth of the two strains was more sensitive to most tested fungicides than those of chlamydospore germination. Chlamydospore germination of 610 was more sensitive to tested fungicides than those of 758, and mycelia growth of 758 was more sensitive to most tested fungi-cides than those of 610. Among the seven fungicides, 98% carbendazim had the strongest effects (EC50 values were 1.64 and 0.05 μg/ml), and 70% pentachloroni-trobenzene had the weakest effects (EC50 values were 1.64 and 0.05 μg/ml) for chlamydospore germination and mycelia growth of 610. As for 758, 98% carbendaz-im had the strongest inhibitory effects and 95% metalaxyl had the weakest inhibitory for chlamydospore germination of 758 (EC50 values were 0.62 and 1 108.61 μg/ml respectively), whereas 96.2% tebuconazole showed the strongest inhibitory effects for mycelia growth of 758 (EC50 value was 0.32 μg/ml), and 95% metalaxyl was the weakest (EC50 value was 1 206.29 μg/ml). According to the applied concentration of different fungicides in practice, we concluded that chlamydospore preparations of 610 and 758 could not be combined with carbendazim, tebuconazole, thiram and carboxin for control ing plant diseases, and the pesticide residues to the biocontrol effects should be kept in mind. Chlamydospore preparations of 610 and 758 can be combined with pentachloronitrobenzene and difenoconazole for control ing plant dis-eases, 758 chlamydospore preparations and germinated chlamydospore of 610 can be combined with metalaxyl for control ing plant diseases, and pesticide residue risk was not serious.%为探索化学杀菌剂的施用与残留对木霉菌厚垣孢子制剂的影响，采用孢子萌发抑制法和菌丝生长速率法研究7种常用化学杀菌剂对2株生防木霉菌哈茨木霉610（T. harzianum 610）和长枝木霉758（T. longibrachiatum 758）厚垣孢子萌发和菌丝生长的影响。结果显示，多菌灵、戊唑醇、苯醚甲环唑的抑制作用较强，五氯硝基苯、甲霜灵的抑制作用较弱，福美双、萎锈灵的抑制作用中等。木霉菌菌丝生长比厚垣孢子萌发对杀菌剂更加敏感。7种杀菌剂对610孢子萌发的抑制作用比758强，但多数杀菌剂对610菌丝生长的抑制作用则比758弱。98%多菌灵对610厚垣孢子萌发和菌丝生长的抑制作用最强，70%五氯硝基苯的抑制作用最弱。98%多菌灵对758厚垣孢子萌发的抑制作用最强，甲霜灵的抑制作用最弱。96.2%戊唑醇对758菌丝生长的抑制作用最强，95%甲霜灵的抑制作用最弱。结合各杀菌剂的使用浓度，施用木霉菌610和758厚垣孢子制剂防治病害时，不能与多菌灵、戊唑醇、福美双与萎锈灵结合使用，并且上述4种农药残留可能影响木霉菌剂的防效，可与五氯硝基苯、苯醚甲环唑结合使用。758厚垣孢子制剂可与甲霜灵结合使用，610孢子萌发后可与甲霜灵结合使用。五氯硝基苯、苯醚甲环唑、甲霜灵的农药残留对木霉菌剂的影响不大。