Watermelon planting is capable to restructure the soil microbiome that regulated by reductive soil disinfestation

Reductive soil disinfestation (RSD) is an effective method to suppress many types of soil-borne diseases in various crops. However, the changes of soil-borne pathogens and microbial communities after crop cultivation in the RSD-treated soils are poorly understood. In the present study, pot experiment was conducted to evaluate the impacts of RSD treatment, with the incorporation of sugar fermentation liquor, on soil Fusarium oxysporum populations, microbial activities, and microbial communities at both after RSD treatment and watermelon planting. The results showed that RSD treatment could considerably inhibit the F. oxysporum and Fusarium wilt disease, promote the growth of watermelon, and enhance microbial activity. However, the pathogen of F. oxysporum resurged quickly after the watermelon cultivation. Although RSD treatment could significantly alter soil microbial communities, the watermelon cultivation also had the capacity to restructure the soil microbial communities to a similar status with control. Collectively, RSD treatment could considerably reduce soil conduciveness to Fusarium wilt and this conduciveness was quickly resurged after watermelon planting. Thus, the changes of F. oxysporum and soil microbial community after watermelon cultivation were likely due to the root exudates released by watermelon that had enough powerful driving force to select similar taxa by filtering the microbial seed bank.