番茄晚疫病菌拮抗菌株筛选鉴定及其作用机制OA

To screen microbial resources for the control of tomato late blight caused by pathogen Phy-tophthora infestans,strains with strong antagonistic activity were isolated from soil using the plate con-frontation method.Their taxonomic status was determined using integrating morphological,physiologi-cal,and biochemical characteristics,combined with the 16S rDNA gene sequence analysis.The antifun-gal activity,action mechanisms,and control effect of the antagonistic strains were investigated via the mycelial growth inhibition method,spore germination assay,and pot experiment.The results showed that a total of 11 strains exhibited antagonistic activities against P.infestans.Among these antagonistic strains,strain C-21 exhibited the highest mycelial growth inhibition rate of 84.41%,and it was identi-fied as Streptomyces flavogriseus.This strain could produce extracellular enzymes including cellulase,protease and amylase.Its fermentation broth could disrupt the mycelial morphology and cell membrane integrity of P.infestans,and significantly inhibited spore germination and zoospore release,with inhibi-tion rates of 69.31%and 57.94%,respectively.The preventive and curative control effects of strain C-21 against tomato late blight were 43.57%and 59.28%,respectively.These findings indicated that strain C-21 had an excellent control effect on tomato late blight,and exhibited promising biocontrol potential for further development and application.