中文摘要：

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。

英文摘要：

Bioactivities of five different fungicides （carbendazim, mancozeb, dimethachlon, iprodione and difenoconazole） to Rhizoctonia solani were determined using bioassay methods at the stages of mycelial growth, sclerotium production and germination. And in vivo protective and curative effects of these fungicides against tobacco sore shin on detached leaves were also analyzed. The results showed that the five selected fungicides exhibited different inhibitory activities at all assays. The most effective fungicide against the mycelial growth, sclerotium production and germination of R. solani was carbendazim, with the average mycelial growth ECs0 value of （0.06 ± 0.01） mg/L, 0.25 and 20 mg/L of carbendazim exhibited 100% inhibition against sclerotium production and germination, respectively. For iprodione, its average ECs0 value for mycelial growth was （0.35 ± 0.15） mg/L, 2 and 100 mg/L of iprodione exhibited （54.79 ± 12.58）% and 100% inhibition against sclerotium production and germination, respectively. For difenoconazole, its average EC50 value was （0.55 ± 0.53） mg/L, 5 and 200 mg/L of difenoconazole exhibited （97.97 ± 2.64）% and 100% inhibition, respectively. For dimethachlon, its average ECs0 value was （1.31 ± 0.14） mg/L, 10 and 100 mg/L of difenoconazole all exhibited 100% inhibition. The lowest was detected in the case of mancozeb, with average ECs0 value of（6 ± 0.20） mg/L, 10 and 100 mg/L of mancozeb exhibited approximately （43.58 ± 31.87）% and 0 inhibition, respectively. The most effective fungicides for protective activity were carbendazim, iprodione and dimethachlon （all showed 〉 99% efficacy at 50 mg/L）, followed by mancozeb （75.83%）, and the lowest activity was detected in the case of difenoconazole （39.29%）. The most effective fungicide for curative activity was carbendazim （50 mg/L exhibited 93.46% efficacy）, followed by dimethachlon, iprodione and difenoconazole （all showed 〉 84% efficacy at 200 mg/L）, and lowest activity was observed in