拮抗菌群对烟草野火病的防治效果及叶际微生物群落多样性的影响

Effects of antagonistic bacteria on tobacco wild fire and responses of phyllosphere microbiota

【背景】烟草野火病(Tobacco Wild Fire)是烟草上的主要病害之一,利用拮抗菌防治烟草野火病是具有较好前景的防治手段。【目的】分析烟草叶际微生物群落结构组成和多样性,阐释拮抗菌群施用对烟草野火病的防治效果及对叶际微生物群落的影响。【方法】在烟草上施用3种拮抗菌群,采用16Sr RNA基因高通量测序及生物信息学手段,分析拮抗菌群对烟草叶际微生物群落结构组成和多样性的影响,研究拮抗菌群在叶片上的定殖。【结果】拮抗菌群对烟草野火病的防治效果达到50.44%-68.58%。与对照相比,3种拮抗菌群处理叶际微生物群落结构和组成都产生了明显的变化,群落多样性显著增高。拮抗菌群处理后,烟草叶际微生物泛菌(Pantoea)、寡养单胞菌(Stenotrophomonas)和假单胞菌(Pseudomonas)等菌属所占比例发生显著变化,其中芽孢杆菌属(Bacillus)和寡养单胞菌属相比对照增加分别达到3.9倍和7.02倍,其丰度与病情指数显著负相关。【结论】拮抗菌群对烟草野火病有较好的防治效果,施用拮抗菌群显著影响叶际微生物群落的组成和多样性,假单孢杆菌和寡养单胞菌等优势菌属能够在烟草叶际定殖,起到防治烟草野火病的作用。

[Background]Tobacco wild fire is one of the main diseases on tobacco.It is a promising method to control tobacco wild fire with antagonistic bacteria.[Objective]To analyze the composition and diversity of microbial community in tobacco leaf,and explain the control effect of antagonistic bacteria on tobacco wild fire.[Methods]Three antagonistic groups were applied to tobacco,and the effects of antagonistic groups on the structure and diversity of tobacco leaf microbial community were analyzed by 16 S rRNA gene high-throughput sequencing and bioinformatics.[Results]The control effect of antagonistic bacteria on tobacco wild fire reached 50.44%-68.58%.The community structure and composition of antagonistic groups had significant changes,was significantly higher community diversity,compared with the control group.After treatment with antagonistic flora,the proportion of tobacco leaf microflora,such as Pantoea,Stenotrophomonas and Pseudomonas,changed significantly,Bacillus and Stenotrophomonas increased by 3.9 and 7.02 times,respectively,compared with the control.The abundance was negatively correlated with disease index.[Conclusion]The antagonistic bacteria had a good control effect on tobacco wild fire.The composition and diversity of the microbial community in the tobacco leaves were significantly affected by the application of antagonistic bacteria.The dominant bacteria such as Pseudomonas and Stenotrophomonas could colonize in the tobacco leaves and play a role in controlling tobacco wild fire.