Abstract:The stem base rot of Passiflora is one of the most serious soil-borne diseases endangering the production of Passiflora, and there is no reliable treatment method, which seriously affects the development of Passiflora industry. To explore the correlation between the occurrence of stem base rot of Passiflora and soil physico-chemical properties and bacterial genetic diversity in this study, providing a theoretical basis for the comprehensive control of stem base rot of Passiflora. The incidence of Passiflora base rot diseases in three topographical orchards, including paddy fields, dry farms and mountainous areas were investigated. The soils were collected from infected and normal plants in three Passiflora planting areas, respectively, and the physico-chemical properties, including pH value, conductivity (EC), and water content were measured. The V4 hypervariable regions of soil bacteria16SrDNA were sequenced by high-throughput sequencing, and the relationship and diversity index of bacterial communities were analyzed by Venn correlation, cluster analysis, genetic diversity, community structure differences and principal component analysis (PCA). The incidence of Passiflora base rot is the highest in paddy fields(80.67%), followed by dry lands (52.67%), and mountainous ereas (15.33%). The pH value and electrical conductivity of paddy soils were highest(7.25 and 49.43 us/cm), followed by dry lands(5.18 and 48.27 us/cm) and mountainous area(4.57 and 39.73 us/cm). The bacterial community abundance is the highest in paddy fields, followed by dry lands and mountainous areas, and is higher in soils of infected plants than that of normal plants. The bacterial community diversity is the highest in dry lands, followed by mountainous areas and paddy fields. There is a large difference in the bacterial community structure between groups in different topographic soils, while the similarity is low within groups of the paddy field, and high within groups of dry lands and that of mountain areas. The incidence rate of stem base rot in passionflower orchards is significantly correlated with physico-chemical properties, topographic factors and bacterial diversity in soils.