Author(s)

Jin Li, Bohao Chen, Kai Deng, Yanqiu Liang, Zhong Lin, and Tingting Duan

Corresponding Author

Tingting Duan

Abstract

Background and objective: Fusarium wilt (Panama disease) of banana is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC), whose proliferation is favored under acidic soil conditions. This study investigated whether soil microbial functional diversity is associated with interactions between fertilizer pH and FOC spore inoculate. Method: Pseudostems (n = 180) were grown in pots in mixed soil (pH 6. 09). In a 3×5 design, each pot was inoculated with 0, 103, or 106 cfu FOC/g of soil, and irrigated each week with pH 5, 6, 7, 8, or 9 fertilizer; N, P2O5, and K2O were identical. At 65 days, spore suspensions were prepared from soil samples. Community level physiological profiling (CLPP) was conducted, using the Biolog EcoPlate method, through indices of carbon source utilization that reflect the metabolic functional diversity of soil microbes: average well color development (AWCD), richness (R), Shannon-Weaver diversity index (H'), and the Simpson dominance index (D). Principal component analysis (PCA) of the functional diversity of microbes was applied. Results: AWCD was significantly higher in treatments consisting of no FOC inoculate and alkaline fertilizer compared with other treatments, and R, H', and D were also notably higher (72 h). Results of PCA revealed that the diversity of soil microbes was higher under alkaline fertilizer treatment, but lower under conditions of FOC inoculation. Conclusions: The application of alkaline fertilizer increases the functional diversity of soil microbial populations.

Keywords

Alkaline fertilizer, FOC, Soil microbe, Diversity of microbial community, Biolog-EcoPlate