Effects of interplanting of banana with black-skinned wax gourd on controlling Fusarium wilt and soil microbial community

【Objective】An attempt was made to explore the effects on controlling Fusarium wilt and the structure of soil bacterial community after banana was intercropped with black-skinned wax gourd, to provide theoretical reference for the comprehensive controlling of banana Fusarium wilt.【Method】The resistance(tolerance) Fusarium wilt variety Guijiao 9 and susceptible Fusarium wilt variety Guijiao 1 were used as experimental materials. A randomized block experiment was carried out in a banana orchard with an incidence of Fusarium wilt more than 50%. There were four treatments, Guijiao 9/black-skinned wax gourd intercropping, Guijiao 9 monoculture, Guijiao 1/black-skinned wax gourd intercropping and Guijiao 1 monoculture. Investigated incidence of banana Fusarium wilt, postharvest yield of banana and wax gourd, collected the orchard soil after the balck-skinned wax gourd were harvested, detected the physical and chemical properties of soil and the number of microorganisms. High-throughput sequencing technology was used to determine the soil bacterial community structure and composition among different treatments.【Result】The incidences of Fusarium wilt were 1.48%, 14.44%, 52.96% and 70.00% respectively, after Guijiao 9/black-skinned wax gourd intercropping, Guijiao 9 monoculture, Guijiao 1/black-skinned wax gourd intercropping and Guijiao 1 monoculture. There was no significant difference in the average yield of banana/black-skinned wax gourd intercropping and banana monoculture(P>0.05), but the banana yield per hectare increased due to the decrease of the incidence of Fusarium wilt. Compared with different resistant banana varieties monoculture, the pH value of Guijiao 9 and Guijiao 1/black-skinned wax gourd intercropping significantly increased by 24.00% and 19.45%, respectively(P<0.05), the soil electrical conductivity(EC) value significantly decreased by 78.48% and 72.55%, and the content of soil alkali-hydrolyzable nitrogen significantly increased by 72.92% and 72.73%. The number of soil bacteria and actinomycetes increased significantly, Chaol index and Shannon index increased significantly, and Simpson index decreased significantly. Different resistant banana varieties(resistant and susceptible varieties)/black-skinned wax gourd intercropping increased the relative abundance of Proteobacteria, Firmicutes, Acidobacteria, Gemmatimonadetes and Bacteroidetes of soil bacteria, and decreased the relative abundance of Chloroflexi and Actinobacteria. Different resistant banana varieties(resistant and susceptible varieties)/black-skinned wax gourd intercropping changed the structure of soil bacterial community and increased the diversity and richness of soil bacteria. The effect of interplanting black-skinned wax gourd with Fusarium wilt resistance(tolerance) banana varieties was more obvious than that of susceptible varieties.【Conclusion】Fusarium wilt resistance(tolerance) banana varieties/blackskinned wax gourd intercropping can reduce the incidence of banana Fusarium wilt by increasing soil pH, reducing EC value, increasing soil alkali-hydrolyzable nitrogen content and changing soil microbial community structure. Fusarium wilt resistance (tolerance) banana varieties/black-skinned wax gourd intercropping can be promoted in in banana Fusarium wilt disease areas in Guangxi.