Biological agent is an important green pathway to control Verticillium wilt. A field experiment was performed to examine the effects of Bacillus subtilis agent (15, 30 and 45 kg·hm-2), Trichoderma humatum agent (15, 18 and 24 kg·hm-2), 'Yufeng 99' agent (15, 22.5 and 30 kg·hm-2) and Zhongnonglyukang agent (30, 45 and 60 kg·hm-2) on cotton Verticillium wilt and soil microbial community. The results showed that all of the four biological agents could reduce the incidence and index of cotton Verticillium wilt, with control effects of 50.0%-77.4% in the whole growth period of cotton. The control effects of B. subtilis, 'Yufeng 99' and Zhongnonglyukang agent were positively correlated with the application doses, while that of T. humatum agent of 18 kg·hm-2 was significantly higher than 15 and 24 kg·hm-2. The relative abundance of V. dahliae was significantly reduced, which was negatively correlated with the control effect. The quantity and species richness of soil bacteria were significantly increased with the increases of application doses. The quantity and species abundance of actinomycete were significantly increased, while the quantity of actinomycete varied greatly among different application doses. The quantity and species richness of fungi increased with the increased application doses of T. humatum agent, but was decreased with the increased application doses of other three biological agents, respectively. The control effect was positively correlated with the quantity of bacteria and actinomycetes, but was negatively correlated with that of fungi. Meanwhile, the control effect was significantly and positively correlated with the abundance of Actinomycetes, Nitrospirae, Ascomycota, Chytridiomycota, but was significantly and negatively correlated with that of Deuteromycota. The application doses of 'Yufeng 99', zhongnonglyukang, B. subtilis and T. humatum agents were suggested to be 30, 60, 45 and 18 kg·hm-2, respectively.
生物农药是当前棉花黄萎病绿色防治的重要途径.本研究设置田间小区试验,研究了4种生物药剂不同滴施用量(枯草芽孢杆菌粉剂15、30、45 kg·hm-2,“施倍健”哈茨木霉菌剂15、18、24 kg·hm-2,渝峰“99植保”15、22.5、30 kg·hm-2,中农绿康30、45 和60 kg·hm-2)对棉花黄萎病的防治效果及土壤微生物群落组成和多样性的影响.结果表明: 各施药处理均不同程度降低了棉花黄萎病发病率和发病指数,全生育期平均防病效果达到50.0%~77.4%;木霉菌剂施药量18 kg·hm-2的防效显著高于15 和24 kg·hm-2,其他3种药剂防病效果均与施药量呈正相关.施药后土壤中病原菌大丽轮枝菌的相对丰度显著降低,且与防病效果呈极显著负相关.土壤细菌的数量与物种丰度随着施药量的增加而显著增加.施药后土壤放线菌的数量与物种丰度也显著增加,但放线菌数量在不同施药量间相差较大.土壤真菌的数量与物种丰度除木霉菌剂随施药量增加而增加外,其他3种药剂随着施药量的增加而减少.Pearson相关性分析显示,施药组的防病效果与细菌和放线菌数量呈正相关关系,而与真菌数量呈显著负相关;与放线菌、硝化螺旋菌门细菌、子囊菌门真菌、壶菌门真菌丰度呈现显著正相关,而与半知菌门真菌丰度呈显著负相关.建议在滴施用量上渝峰“99植保”30 kg·hm-2、中农绿康60 kg·hm-2、枯草芽孢杆菌可湿粉剂45 kg·hm-2、“施倍健”哈茨木霉菌剂18 kg·hm-2.
Keywords: Verticillium wilt control effect; biological agent; cotton; dripping; high-throughput sequencing; soil microorganism.