Effects of soybean intercropping on tobacco leaf microbial communities in different regions

Soybean intercropping was adopted to address the problem of tobacco continuous cropping. Leaf microbes are crucial for the growth and development of tobacco plants, but the impact of soybean intercropping on the tobacco leaf microbial community remains unclear. This study aimed to investigate the effects of soybean intercropping, different growth stages, and different planting regions on tobacco leaf microbial communities.

High-throughput sequencing was used to analyze tobacco leaf microbial communities at the vigorous growth stage and mature stage across six tobacco-producing regions in Zunyi, Guizhou. A control group (monocropped tobacco) and a soybean intercropping group were set up in each region. The results showed that different growth stages had the greatest impact on the tobacco leaf microbial community, followed by different planting regions, while soybean intercropping had the smallest impact. All grouping strategies altered the structure of the tobacco leaf microbial community but not the structure and putative functional characteristics of its core microbial community. Soybean intercropping reduced the statistical correlation among core microbial communities. The core fungi and bacteria were identified as Neodidymella and Exiguobacterium, respectively.

Different growth stages have a greater impact on the structure of the tobacco leaf microbial community than soybean intercropping. Soybean intercropping alters the structure of the tobacco leaf microbial community and reduces the statistical correlation among core microbial communities, but does not affect the structure and putative functional characteristics of the core microbial community.