Soils naturally suppressive to banana Fusarium wilt disease harbor unique bacterial communities

Banana Fusarium wilt disease is caused by the Fusarium oxysporum f. sp. cubense race 4 fungus and is a vast problem for global banana production. Suppressive and conducive soils were analyzed to characterize important microbial populations and soil chemical properties that contribute to disease suppressiveness. Soil bacteria communities from the two banana orchards with excellent Fusarium disease suppression (suppressive soil) after long-term monoculture and two adjacent banana orchards with serious Fusarium wilt disease (conducive soils) were compared using deep 16S RNA barcode pyrosequencing. Compared to the conducive soils within the same field site, higher (P < 0.05) richness and diversity indices were observed in both suppressive soils. Moreover, more operational taxonomic units (OTUs) were observed in the two suppressive soils. Hierarchical cluster analyses showed that bacterial community membership and structure in disease-suppressive soils differed from disease-conducive soils. The Acidobacteria phylum was significantly (P < 0.05) elevated, but Bacteroidetes was significantly (P < 0.05) reduced in suppressive soils. The Gp4, Gp5, Chthonomonas, Pseudomonas, and Tumebacillus genera were significantly (P < 0.05) enriched in suppressive soils, but Gp2 was significantly (P < 0.05) reduced in suppressive soils. Furthermore, the enrichment of Gp5 and Pseudomonas as well as the soil physicochemical properties of available phosphorus were significantly (P < 0.05) correlated with disease suppression. Naturally disease suppressive soils to banana Fusarium wilt disease harbor unique bacterial communities.