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采用生物测定方法分析了烟草立枯病菌Rhizoctonia solani在菌丝生长、菌核形成与萌发阶段对5种杀菌剂(多菌灵、代森锰锌、菌核净、异菌脲及苯醚甲环唑)的敏感性,同时通过离体叶片法考察了5种杀菌剂对烟草立枯病的保护和治疗作用。结果表明:供试5种药剂对立枯病菌菌丝生长、菌核形成与萌发均表现出了不同程度的抑制活性,同时对烟草立枯病具有一定的保护和治疗作用。其中,对菌丝生长以及菌核形成与萌发抑制活性最强的均是多菌灵,其抑制菌丝生长的EC50平均值为(0.06±0.01)mg/L,0.25和20 mg/L下对菌核形成和萌发的抑制率均为100%;其次为异菌脲[EC50值为(0.35±0.15)mg/L,2和100 mg/L下对菌核形成和萌发的抑制率分别为(54.79±12.58)%和100%]、苯醚甲环唑[EC50值为(0.55±0.53)mg/L,5和200 mg/L下对菌核形成和萌发的抑制率分别为(97.97±2.64)%和100%]及菌核净[EC50值为(1.31±0.14)mg/L,10和100 mg/L下对菌核形成和萌发的抑制率均为100%];最弱的均是代森锰锌,其抑制菌丝生长的EC50平均值为(6±0.20)mg/L,10和200 mg/L下对菌核形成和萌发的抑制率分别为(43.58±31.87)%和0。离体试验表明:对烟草立枯病保护作用最强的是多菌灵、异菌脲和菌核净,50 mg/L时防效均>99%,其次为代森锰锌(50 mg/L防效为75.83%),最弱的是苯醚甲环唑(50 mg/L防效为39.29%);治疗作用最强的也是多菌灵,50 mg/L防效为93.46%,其次为菌核净、异菌脲和苯醚甲环唑(200 mg/L时防效均>84%),最弱的为代森锰锌(800 mg/L时防效为76.40%)。研究结果可为烟草立枯病化学防治药剂筛选提供参考和依据。
The bioassay method was used to analyze the effects of five fungicides (carbendazim, mancozeb, sclerotinum, iprodione and phenyl ether ring) on mycelial growth, sclerotial formation and germination of Rhizoctonia solani. Azole). At the same time, the protective and therapeutic effects of five fungicides on tobacco leaf blight were investigated by in vitro leaf method. The results showed that the tested five kinds of agents showed different degrees of inhibitory activity on the mycelium growth, sclerotia formation and germination of Rhizoctonia solani, and had some protective and therapeutic effects on the tobacco blight. Among them, the mycelium growth and sclerotia formation and germination inhibitory activity are the strongest carbendazim, its inhibition of mycelial growth EC50 (0.25 ± 0.01) mg / L, 0.25 and 20 mg / L The inhibitory rates of sclerotia formation and germination were 100%, followed by iprodione (EC50 = 0.35 ± 0.15) mg / L, and the inhibitory rates of sclerotia formation and germination at 2 and 100 mg / L were ( 54.79 ± 12.58)% and 100%]. The inhibitory rates of difenoconazole [EC50 (0.55 ± 0.53) mg / L, 5 and 200 mg / L on sclerotia formation and germination were (97.97 ± 2.64 ) And 100%], and sclerotium [EC50 (1.31 ± 0.14) mg / L and 100 and 100% inhibition rates of sclerotia formation and germination at 10 and 100 mg / L, respectively] The mean EC50 of mancozeb against mycelial growth was (6 ± 0.20) mg / L, and the inhibitory rates of fungi formation and germination at (10 and 200 mg / L) were (43.58 ± 31.87)% and . In vitro tests showed that the strongest protective effect against tobacco leaf blight was carbendazim, iprodione, and sclerotinum. The control effect was> 99% at 50 mg / L, followed by mancozeb (50 mg / L was 75.83%), and the weakest was difenoconazole (50 mg / L, 39.29%). The most effective treatment was carbendazim, with the efficacy of 50 mg / L being 93.46%, followed by Is mycophenolate, iprodione and difenoconazole (> 84% at 200 mg / L) and mancozeb (76.40% at 800 mg / L) is the weakest. The results can provide reference and basis for chemical control of tobacco leaf blight.