微生物菌剂对烟草根结线虫及根际微生物群落多样性的影响

Effects of Microbial Agents on Tobacco Root-knot Nematode and Diversity of Rhizosphere Microbial Communities

为寻找对烟草根结线虫病有良好控制效果的药剂,探究药剂施用对烟草根际土壤微生物群落的代谢情况,改善土壤微生态环境,以烟草品种红花大金元为试验材料,通过田间试验研究施用枯草芽孢杆菌、淡紫拟青霉、荧光假单胞杆菌、哈茨木霉和阿维菌素、阿维·丁硫对烟草根结线虫病病害控制、根际土壤微生物群落多样性变化及烟草生长的影响。结果表明,淡紫拟青霉、荧光假单胞杆菌能够分别达到89%、76%的防治效果。AWCD 值、McIntosh 指数、Simpson 指数均显示土壤中增施微生物菌剂能够提高根际土壤微生物群落代谢能力,促进土壤微生物群落对碳源的整体利用,增强代谢活性。Pearson相关分析表明,根际土壤中微生物群落对31 种碳源的代谢利用与病情指数呈负相关。土壤中添加微生物菌剂淡紫拟青霉、枯草芽孢杆菌、荧光假单胞杆菌均能够控制烟草根结线虫病,增强土壤微生物群落多样性,促进烟株生长,淡紫拟青霉效果最好。淡紫拟青霉处理后通过提高根际土壤微生物对碳水化合物类(D-半乳糖酸-γ-内酯)碳源的代谢利用,达到对病情指数的有效调控。淡紫拟青霉处理除最大叶长外,株高、茎围、有效叶片数、最大叶宽均为最大增幅分别为44.91%、20.11%、11.78%、39.05%。

In order to find a crop protection agent with good control effect on tobacco root-knot nematode disease, and to explore the metabolism of microbial community in tobacco rhizosphere soil and improve the soil micro-ecological environment, using the tobacco variety Honghua Dajinyuan as the experimental material in a field trial, B. subtilis, P. lilacinus, P. fluorescens, T. harzianum and avermectin, avermectin-butyl sulfate were selected for comparison. The effects on tobacco root-knot nematode disease control, metabolic diversity of rhizosphere soil microbial community and tobacco growth were studied. The results showed that P. lilacinus and P. fluorescens could achieve 89% and 76% control effects, respectively. AWCD value, McIntosh index and Simpson index all showed that the application of microbial agents in soil could increase the diversity of soil microbial communities, promote the overall utilization of carbon sources by soil microbial communities, and enhance metabolic activity. Pearson correlation analysis showed that the metabolic utilization of 31 carbon sources in microbial communities in rhizosphere soil was negatively correlated with disease index. The addition of microbial agents such as P. lilacinus, B. subtilis and P. fluorescens in soil can control tobacco root-knot nematode disease, enhance soil microbial community diversity, and promote the growth of tobacco. After treatment with P. lilacinus, the metabolic utilization of carbon sources was improved by increasing the metabolism of carbohydrates (D-galactosidase-γ-lactone) in rhizosphere soil microorganisms to achieve effective control of the disease. The P. lilacinus treatment also brought about the biggest increase in plant height, stem circumference, effective leaf number and maximum leaf width of 44.91%, 20.11%, 11.78% and 39.05%.