不同类型杀菌剂对烟草黑胫病菌生物活性的研究

Biological activity of different fungicide controlling tobacco black shank

研究了烯酰吗啉、嘧菌酯、醚菌酯、甲霜灵及代森锰锌5种不同类型杀卵菌剂对烟草黑胫病菌菌丝生长、孢子囊产量、游动孢子释放、孢子囊直接萌发及休止孢萌发的生物活性。结果表明:烯酰吗啉和甲霜灵对菌丝生长具有强烈的抑制作用,其次为代森锰锌,嘧菌酯和醚菌酯的活性最低;烯酰吗啉和甲霜灵对孢子囊的形成也具有很高的抑制活性,显著高于其它类药剂;游动孢子的释放对嘧菌酯和醚菌酯最为敏感,其次为代森锰锌,而烯酰吗啉和甲霜灵对其没有抑制作用;孢子囊的直接萌发对嘧菌酯和醚菌酯最为敏感,其次为烯酰吗啉和代森锰锌,而甲霜灵对此阶段没有活性;休止孢的萌发对嘧菌酯和醚菌酯最为敏感,其次为烯酰吗啉、代森锰锌,而甲霜灵不影响其萌发。

Effects of fungicides dimethomorph, azoxystrobin, kresoxim-methyl, metalaxyl and mancozeb on mycelial growth, sporulation, zoospores release and germination of sporangia as well as of cystospores of Phytophthora parasitica were studied. Results showed that dimethomorph and metalaxyl inhibited mycelial growth more effectively than other fungicides tested in order of mancozeb, azoxystrobin, kresoxim-methyl. Sporangia production was reduced by dimethomorph and metalaxyl more than by azoxystrobin, kresoxim-methyl or mancozeb. Zoospore release from sporangia was most sensitive to azoxystrobin and kresoxim-methyl, less sensitive to mancozeb and insensitive to dimethomorph and metalaxyl. Direct germination of sporangia of P. parasitica was inhibited by azoxystrobin and kresoxim-methyl, followed by dimethomorph and mancozeb, whilst was insensitive to metalaxyl. Germination of encysted zoospores of P. parasitica was most sensitive to azoxystrobin and kresoxim-methyl, followed by dimethomorph. Mancozeb was moderately active, while metalaxyl showed no effects.