根腐甜瓜根际土壤真菌群落特征及其影响因素OA

To elucidate the fungal community characteristics in the rhizosphere soil of root rot Cucumis melo and its influ-encing factors,and to provide a theoretical basis for the prevention and control of root rot disease,this study collected healthy and root rot C.melo rhizosphere soil from the facility cultivation base in Tonghai county,Yuxi city,Yunnan prov-ince.The physicochemical properties and enzymatic activities were measured,and high-throughput sequencing technolo-gy was used to quantitatively analyze the composition and diversity of soil fungal community.The results showed that compared with the healthy group,the root rot group displayed significantly increased soil pH,electrical conductivity,or-ganic matter content,and ammonium nitrogen content,while the content of available phosphorus and potassium,as well as the activities of urease,catalase,and protease were reduced.The fungal community structures in the rhizosphere soil of the root rot and healthy group were clearly differentiated.Furthermore,the relative abundance of potential pathogenic fun-gi,such as Fusarium,Plectosphaerella,Byssochlamys,and Humicola,was significantly increased in the root rot group.Functional predictions of the fungal community indicated that the relative abundance of plant pathogens in the root rot group was 41.69％,which was significant higher than the healthy group.RDA analysis revealed that the relative abun-dance of potential pathogenic fungi was positively correlation with soil pH,EC value,organic matter content,and ammo-nium nitrogen content,and negatively correlated with available phosphorus,available potassium,nitrate nitrogen content,and the activities of urease and catalase.In summary,soil salinization,nutrient imbalance,reduced enzymatic activity,in-creased relative abundance of pathogenic fungi,and the reduction of beneficial fungi in the facility cultivation environ-ment may all contribute to the occurrence of root rot disease in C.melo.This study provides a scientific basis for reveal-ing the ecological mechanisms of this disease and developing prevention and control measures.