人参致病菌拮抗菌株的筛选及鉴定

Screening and Identification of Antagonistic Strains against Phytopathogens of Panax ginseng

目的:筛选对人参黑斑菌、人参锈腐菌等人参致病菌有较好抑菌活性的微生物菌株,为人参病害生防防治提供参考依据。方法:采用平板稀释法从人参栽培土壤和菌剂产品中分离菌株;以人参致病菌为靶标,采用对峙培养法筛选拮抗菌;分别采用16S r DNA和28S r DNA序列分析方法鉴定细菌和真菌菌株的分类学地位。结果:共计从人参栽培土壤中分离到66株菌,其中菌株X对人参致病菌表现较好抑菌活性;从商品化菌剂中分离出17株菌,其中菌株QM、BM2、HZ3、GG、HC和DD对人参致病菌表现较好抑菌活性。经鉴定,菌株X为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),QM、BM2和HZ3为甲基营养型芽孢杆菌(B.methylotrophicus),GG为枯草芽孢杆菌(B.subtilis),HC为棘孢木霉(Trichoderma asperellum),DD为平展木霉(T.effusum)。结论:筛选出的7株拮抗菌对多种人参致病菌有较好抑菌活性,菌株X可用于生防菌剂开发,与菌株QM、BM2、HZ3、GG、HC和DD对应的商品化菌剂可用于人参病害防治。

Objective： To screen strains that having antagonistic activity against Cylindrocarpon destructans, Alterna- ria panax etc. , providing references for biocontrol of soilborne diseases prevailing in P. ginseng. Methods： Strains were sepa- rated from ginseng-cultivating soils and commercial microbial agents by the plate dilution method. Confronting culture method was used to screen antagonistic strains against pathogens of P. ginseng. Antagonistic agents were identified by 16S and 28S ribo- somal DNA sequencing. Results： In total, 66 stains were isolated from ginseng cultivating soil. Among them, strain X shown significant antagonistic activity against pathogens of P. ginseng. Another 17 stains were isolated from commercial microbial pesti- cides, in which strains QM, BM2, HZ3, GG, HC and DD had antagonistic activity against pathogens of P. ginseng. Homology results showed that, strain X was identified as B. amyloliquefaciens, QM, BM2 and HZ3 was Bacillus methylotrophicns, GG was B. subtilis, HC was Trichoderma asperellum and DD was T. effusum. Conclusion： Seven strains hav- ing antagonistic activity against pathogens of P. ginseng were identified. Strain X can be used to develop microbial pesticide, while commercial agents corresponding to QM, BM2, HZ3, GG, HC and DD can be used directly to control soil-borne disea- ses of P. ginseng.