The inhibitory effect of two bacteria on 9 alfalfa pathogens were tested on PDA medium using the confrontation method;the taxonomic status of each pathogen species were determined using morphological and molecular criteria.The bacteria identified were Bacillus amyloliquefaciens and Streptomyces kanamycin.The inhibitory effect of Bacillus amyloliquefaciens ranged from 24.02％-71.11％,with the greatest effect shown against Cercospora medicaginis (71.11％),Stemphylium botryosum (64.76％) and Fusarium roseum (60.55％).The inhibitory range of Streptomyces kanamycin was similar (49.95％-76.90％) with greatest effect against Colletotrichum trifolii (76.90％),Phoma medicaginis (70.94％),Stem ph ylium botryosum (68.01 ％) and Leptosphaerulina briosiana (60.99 ％).Bacillus amyloliquefaciens and Streptomyces kanamycin showed varying degrees of antagonism to different alfalfa pathogenic fungi indicate that they have promise as biological control agents for a variety of Medicago sativa foliar diseases,suggesting further development should be undertaken.%本研究采用革兰氏染色、显微观察和分子生物学方法鉴定了2种具有拮抗潜力的微生物的分类地位,采用PDA培养基平板对峙法测定了其对苜蓿茎点霉(Phoma medicaginis)等9种常见的紫花苜蓿主要病原真菌的拮抗效果.研究结果表明这2种菌分别为解淀粉芽孢杆菌(Bacillus am yloliquefaciens)和卡那霉素链霉菌(Strepto-myces kana m yceticus).前者对供试病原菌的抑菌率为24.02％～71.11％,其中对苜蓿尾孢菌(71.11％)、苜蓿匍柄霉(64.76％)和粉红镰孢(60.55％)抑菌效果最强;后者对供试病原菌抑菌率为49.95％～76.90％,其中对三叶草刺盘孢(76.90％)、苜蓿茎点霉(70.94％)、苜蓿匍柄霉(68.01％)和苜蓿小光壳(60.99％)抑制效果较强.两株菌对供试苜蓿9种病原真菌均表现出不同程度的拮抗作用,该研究结果为解淀粉芽孢杆菌和卡那霉素链霉菌作为紫花苜蓿多种病害的生物防治资源以及进一步开发利用提供了理论依据.
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