Abstract:

To study the effect of tobacco-Zingiber officainale Roscoe rotation on the microbial diversity of tobacco rhizosphere soil, the microbial diversity and compositional structure differences of rhizosphere soil in continuous cropping tobacco fields (CK) and rotated tobacco fields were studied through high-throughput sequencing. The results showed that the disease index of tobacco black shank in the tobacco-Zingiber officainale rotation fields was significantly lower than that in the continuous cropping fields by 40.20%. Compared with the soil in the continuous cropping fields, tobacco-Zingiber officainale rotation significantly increased the community diversity of bacteria and fungi in the soil. Overall, at the phylum level of bacteria, Proteobacteria was the most abundant (CK: 49.10%, SJ: 30.73%), followed by Firmicutes (CK: 42.70%, SJ: 4.65%) and Actinobacteriota (CK: 4.81%, SJ: 23.99%). Among fungi, Ascomycota was the most abundant (CK: 97.52%, SJ: 64.85%), followed by unclassified taxa (CK: 0.35%, SJ: 14.32%) and Basidiomycota (CK: 0.62%, SJ: 8.42%). The differential analysis revealed substantial differences in the composition of the soil microbial community structure between the two treatments (bacteria: R²=0.8520, P=0.001; fungi: R²=0.8782, P=0.001). Specifically, the tobacco-Zingiber officainale rotation significantly enhanced the abundances of certain beneficial microorganisms in the soil, including Chloroflexi, Basidiomycota and Mortierellomycota. Soil environmental factors such as organic matter and total nitrogen were significantly associated with beneficial bacteria such as Lactococcus and Roseiflexaceae. The results provided potential application value for inhibiting the reproduction of pathogenic bacteria and reducing soil diseases by increasing the abundance of these beneficial microorganisms in the soil. At the same time, they offer a new perspective for a deeper understanding of the mechanism of tobacco-Zingiber officainale rotation.

Key words: tobacco, Zingiber officainale, rotation, tobacco black shank disease, microbial diversity