氟唑菌酰羟胺对烟草赤星病的防效及对烟叶和土壤的安全性

Control Effects of Pydiflumetofen on Tobacco Brown Spot and its Safety in Tobacco Leaves and Soil

为明确烟草赤星病菌对新型杀菌剂氟唑菌酰羟胺的敏感性水平以及该药在烟叶和土壤中的安全性,采用菌丝生长速率法和孢子萌发法测定了烟草赤星病菌对氟唑菌酰羟胺的敏感性,并在云南、四川、贵州、福建、重庆等省市开展了田间防效试验,分析了其在烟叶上的残留降解,同时采用高通量测序分析了其对土壤细菌和真菌群落结构和共发生网络的影响。结果表明,烟草赤星病菌在不同发育阶段对氟唑菌酰羟胺敏感性差异较大,其中菌丝生长阶段最为敏感,对169株病株的EC50值为0.0064~0.1832 mg/L。氟唑菌酰羟胺2次施药对烟草赤星病的田间防效达到69.42%~88.09%,并增加了烟叶产量。另外,氟唑菌酰羟胺在鲜烟叶和干烟叶的降解半衰期范围为3.2~8.8 d。氟唑菌酰羟胺使用后土壤中链霉菌属、假单胞菌属、木霉菌属、拟青霉属等有益菌显著富集,且细菌和真菌共发生网络的复杂度增加。因此,氟唑菌酰羟胺可用于烟草赤星病的防治。

To determine the sensitivity level of tobacco brown spot to the new fungicide pydiflumetofen and the safety of this agent in tobacco leaves and soil,the sensitivity of Alternaria.alternata to pydiflumetofen was determined by mycelium growth rate method and spore germination method.Field control tests were carried out in Yunnan,Sichuan,Guizhou,Fujian and Chongqing,and we analyzed the residual degradation of pydiflumetofen in tobacco leaves.Meanwhile,high-throughput sequencing was used to analyze its effects on community structure and co-occurring network of soil bacteria and fungi.The results showed that pydiflumetofen had strong inhibitory activity against A.alternata at different developmental stages,and the mycelium growth stage was the most sensitive.The EC50 range of pydiflumetofen for 169 A.alternata infected strains was 0.0064~0.1832 mg/L.Field experiments showed that the efficacy of pydiflumetofen suspension applied twice on tobacco brown spot ranged 69.42%to 88.09%,and the tobacco yield was increased.In addition,the degradation half-life period of pydiflumetofen in fresh and dry tobacco leaves ranged 3.2~8.8 d.The beneficial microbes such as Streptomyces,Pseudomonas,Trichoderma and Paecilomyces were significantly enriched after the use of pydiflumetofen,and the complexity of bacterial and fungal cogenetic network increased.Therefore,pydiflumetofen can be used for the prevention and control of tobacco brown spot.