烟草黑胫病菌对氟吗啉的敏感性检测及复配药剂的效果评价

Study on sensitivity of Phytophthora nicotianae to flumorph and combinatory fungicide

为明确烟草黑胫病菌对氟吗啉的敏感性,延缓其对氟吗啉抗药性的产生,采用菌落生长速率法测定了烟草黑胫病菌对氟吗啉的敏感性,并利用Wadley方法对不同复配比例的甲霜灵与氟吗啉进行药效评价。选择具有较高抑菌活性的杀菌剂复配比例,采用Abbott模型评价甲霜灵和氟吗啉复配与解淀粉芽孢杆菌ZY-9-13协同使用的效果。结果表明,氟吗啉对71株烟草黑胫病菌菌株的EC50值分布在0.428 5~0.760 8μg/mL之间,平均EC_(50)值为0.588 4μg/mL,敏感性分布呈单峰曲线,未出现抗性菌株。氟吗啉与甲霜灵按体积比1∶10复配时,相加作用最为明显(EC_(50)为0.398 7μg/mL)。复配杀菌剂对解淀粉芽孢杆菌的生长无抑制作用,不同浓度的化学复配药剂与ZY-9-13(浓度为10^(10)cfu/mL)协同使用时,对烟草黑胫病菌的抑制效果高于药剂单独使用的抑制效果,两者具有增效作用。

To investigate the effects of Phytophthora nicotianae to flumorph and delay the development of its flumorph resistance, the sensitivity of P. nieotianae to flumorph was determined by a colony growth rate method. In addition, the effects of Phytophthora nicotianae on a combinatory fungicide （flumorph＋metalaxyl） were evaluated by the Wadley method. The combination ratio of the fungicide with a high antibacterial activity was selected and the synergistic effects of the flumorph and metalaxyl combination and Bacillus amyloliquefaciens ZY-9-13 were evaluated by the Abbott model. The results showed that the EC50 values of 71 strains of P. nicotianae to flumorph ranged from 0.428 5 to 0.760 8 μg/mL with a mean of 0.588 4 gg/mL. The sensitivity distribution was unimodal, and there was no resistant isolate in the 71 strains. The additive effect of the combinatory fungicide at a volume ratio of 1 ： 10 was the most effective （EC50=0.398 7 μg/mL）. The growth of B. arnyloliquefaciens was not affected by the fungicide. The combined application of the fungicide at different concentrations and ZY-9-13 （10^10 cfu/mL） had better inhibitory effects comparing with a single application of each fungicide, and there existed a synergistic effect between them.