Abstract: Tomato grey mould is a worldwide fungal disease caused by Botrytis cinerea. Induced resistance has the advantages of environmental protection and sustainability. In this paper, Pseudomonas choloeaphtis and β-amino butyric acid with potential for resistance were used to determine the anti-disease effect of tomato gray mold and the regulation of rhizosphere bacterial community structure by two pretreatments. The pot test and real-time fluorescence quantitative technology were used to obtain the resistance to gray mold and tomato resistance gene expression under different pretreatments. The 16S rDNA high-throughput sequencing was used to investigate the rhizosphere bacterial community structural change. The results showed that both Pseudomonas choloeaphtis and β-aminobutyric acid treatment could reduce the incidence of tomato plants with reducing the disease index by 60.4% and 36.6% respectively, promoted the expression of resistance genesNPR1andPR1, and stimulated the SA signaling pathway. High-throughput sequencing results showed that pretreatment increased the abundance of Proteobacteria, Pachyphyta and Bacteroides in rhizosphere bacteria, adjusted the abundance and structure of the dominant genus of tomato rhizobacteria. The abundance of probiotic flora in rhizosphere increased significantly.

Key words: gray mold, high-throughput sequencing, tomato, rhizosphere microorganisms, resistance genes