抗多花黄精根腐病生防菌A3-1的促生防病机理OA

This study aimed to explore the green biocontrol methods for root rot of Polygonatum cyrtonema Hua and alleviate the continuous cropping obstacles of P.cyrtonema in Xinhua County,Hunan Province.Four pathogenic fungal species isolated from diseased plants were taken as the target pathogens,and Bacillus subtilis A3-1 screened and identified in our laboratory was used as the biocontrol agent.The biocontrol potential of A3-1 against root rot of P.cyrtonema was systematically evaluated through plate confrontation experiments,evaluation of plant growth-promoting and fungal pathogen-inhibiting functions,antifungal activity evaluation of metabolites,and hyphal morphology observation.The results showed that A3-1 had multiple plant growth-promoting functions such as producing ammonia,fixing nitrogen,secreting siderophores,and solubilzing organic and inorganic phosphorus.Its ACC deaminase activity reached 65.04 U/mL,and it could secrete cellulase,protease,and amylase.The plate confrontation experiments showed that the strain exhibited the best inhibitory effect on Colletotrichum spaethianum,while its volatile metabolites had a high inhibition rate of 91.39%on Fusarium solani,while causing morphological distortion of hyphae.However,the sterile filtrate of this strain did not show significant antifungal activity.In summary,strain A3-1 showed dual functions of promoting plant growth and inhibiting fungal pathogens,with its volatile gas as the key antifungal component,demonstrating promising application prospects in biocontrol.