茄腐镰刀菌拮抗菌株M1的抑菌机理及其促生作用研究

Antibacterial mechanism and growth-promoting effects of antagonistic strain M1 against Fusarium solani

该研究以对茄腐镰刀菌(Fusarium solani)拮抗效果最佳的生防菌M1为研究对象,通过形态学观察、生理生化试验和分子生物学技术对菌株M1进行鉴定。采用平板对峙法评估菌株M1的广谱抗菌效果,利用正丁醇萃取菌株M1发酵产物,通过测定菌丝生长和孢子萌发等方式探究菌株M1对茄腐镰刀菌的抑菌机制,并通过盆栽实验验证其对小麦促生效果。结果表明,菌株M1被鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),对5种真菌显示出不同程度的抑制作用,尤其是对茄腐镰刀菌抑制率达到48.08%。菌株M1发酵产物经过正丁醇提取后,对茄腐镰刀菌的菌丝生长和孢子萌发具有显著的抑制效果,抑制率分别高达76.92%和77.67%。菌株M1能显著破坏茄腐镰刀菌的细胞膜,导致活性氧积累,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性下降,丙二醛(MDA)含量增加。在盆栽试验中,施加M1菌悬液显著促进了小麦生长,尤其在15 d和30 d时,小麦植株鲜质量分别提高了42.46%和61.72%。

In this study,using the biocontrol bacterium M1,which had the optimal antagonistic effect against Fusarium solani as the research object,the strain was identified by morphological observation,physiological and biochemical tests and molecular biology techniques.The broad-spectrum antimicrobial efficacy of strain M1 was evaluated using the plate confrontation method.The fermentation products of strain M1 were extracted with n-butanol,and the inhibitory mechanism of M1 against F.solani was explored by measuring mycelial growth and spore germination.Its growth-promoting effects on wheat was verified by pot experiments.The results showed that strain M1 was identified as Bacillus amyloliquefaciens,displaying varying degrees of inhibitory action against five fungi,especially for F.solani inhibition rate reached 48.08%.The fermentation product of strain M1 extracted by n-butanol had significant inhibitory effects on mycelium growth and spore germination of F.solani,with inhibition rates as high as 76.92%and 77.67%,respectively.Strain M1 could significantly damage the cell membrane of F.solani,resulting in accumulation of reactive oxygen species,decreased activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),and increased malondialdehyde(MDA)content.In pot experiments,the addition of M1 bacterial suspension significantly promoted wheat growth,especially at 15 d and 30 d,the fresh mass of wheat plants increased by 42.46%and 61.72%,respectively.