Suppressing soil-borne Fusarium pathogens of bananas by planting different cultivars of pineapples, with comparisons of the resulting bacterial and fungal communities

Abstract

Fusarium wilt of bananas is a serious soil-borne fungal disease that currently threatens banana production worldwide. There is currently no direct and effective agricultural method for controlling the disease effectively. In this study, a pot experiment was conducted to evaluate the effects of different pineapple cultivars that were planted in a banana orchard soil with high incidences of this disease. The goal of studying this banana-pineapple plantation system was to improve the soil microbial community structure to enhance the control of a number of Fusarium in the banana soil. The soil culturable microorganisms showed that the order of the number of Fusarium from high to low was banana continuous cropping (B) > fallow (CK) > “Golden pineapple” planting (B_GP) > “Bali pineapple” planting (B_BP) > “Tai nong 17 pineapple” planting (B_PP). The MiSeq sequencing results showed that the relative abundance of Fusarium was consistent with the culturable microbial results. Banana-pineapple rotations significantly reduced the abundance of total fungi and F. oxysporum as well as the fungal diversity. The number of Fusarium were significantly reduced, and the banana-pineapple plantings changed the bacterial and fungal communities of soil microbes by increasing the relative abundance of beneficial bacterial and fungal genera such as Desulfurispora, Brockia, Gp1, and Purpureocillium, Talaromyces, respectively. In addition, planting different pineapple cultivars could reduce the soil pH, available nitrogen (AN), available phosphorus (AP) and available potassium (AK), while the organic matter (OM) was increased. Besides, different pineapple cultivars with different soil microbial community structures, and soil fertility indices significantly reduced the relative abundance of Fusarium in the banana orchard soil, and the degree of reduction was from high to low as follows: “B_PP” > “B_GP” > “B_BP”. Our result supports the good application prospects of this rotation for reducing the incidence of soil-borne Fusarium of bananas.