The Impact of the Soil Survival of the Pathogen of Wilt on Soil Nutrient Cycling Mediated by Microorganisms

wilt of in the greenhouse is one of the most severe crop diseases in Shandong Province, P.R. China. This study aimed to investigate the mechanisms of accumulation and long-term survival of the pathogen in naturally pathogenic soils. Soil physicochemical properties were tested after applying a highly virulent strain of wilt to in an artificial disease nursery. The functional structure of soil microorganisms was analyzed through amplicon sequencing. The highly virulent strain SG-15 of f. sp. momordicae was found to cause wilt in in Shandong Province. The strain SG-15 could not infect 14 non-host crops, including and but it had varying degrees of pathogenicity towards 11 varieties. In the artificial disease nursery for wilt of , the was distributed in the soil to a depth of 0-40 cm and was mainly distributed in crop residues at 0-10 cm depth. During crop growth, primarily grows and reproduces in susceptible host plants, rather than disease-resistant hosts and non-host crops. The colonization of the pathogen of wilt significantly changed the soil physicochemical properties, the functional structure of soil microorganisms and the circulation of soil elements such as carbon, nitrogen, phosphorus and sulfur. Soil pH value, organic matter content, available iron content, available manganese content, FDA hydrolase activity and polyphenol oxidase activity were significantly correlated with the relative abundance of wilt pathogens in the soil. In general, this study suggests that susceptible host plants facilitate the accumulation of wilt pathogens in the soil. These pathogens can mediate the decomposition process of plant residues, particularly those of diseased plants, and indirectly or directly affect soil's chemical properties.