为了获得能促进烟草生长和防治黑胫病的稳定菌株，通过常规方法从烟草茎、叶中分离到478株内生细菌，其中65株能拮抗烟草黑胫病菌，占13.60%。菌株YN201408、YN201442、YN201448和YN201458对烟草疫霉的抑菌率分别为63.85%、60.82%、64.72%和76.07%，用1.0×107 cfu/mL拮抗菌液浸烟苗根系30 min，移栽后浇灌1次，在温室盆栽试验中控病效果分别为68.24%、65.47%、69.12和41.40%。YN201448对烟草种子萌芽率和烟草的生长都有促进作用，烟草的发芽率、第5~6真叶期苗高和地上部鲜重分别高于清水对照10.95%、29.31%和67.24%。依据菌体形态、生理生化特征和16S rDNA序列，YN201408、YN201442和YN201448鉴定为解淀粉芽孢杆菌，YN201458为铜绿假单胞菌。YN201448因良好的促生长和控病效果而具有继续开发应用的潜力。%To obtain stable bacterial strains with good growth promotion of tobacco and black shrank disease control effect, 478 endophytic bacterial strains were isolated from tobacco leaves and stems. Among them 65 of strains ( accounting for 13.60%) could inhibit Phytophthora parasitica var. nicotianae by the traditional methodology. Especially, the four strains, YN201408, YN201442, YN201448 and YN201458 inhibited 63.85%, 60.82%, 64.72%and 76.07%of mycelia growth of the pathogen and controlled 68.24%, 65.47%, 69.12 and 41.40%of disease severity by soaking the seedling root in 1.0×107cfu/mL of the bacterial suspension for 30 min and drenching once after transplanting in the pot experiment in the greenhouse, respectively. YN201448 could promote seed germination and growth of tobacco, showing 10.95%, 29.31%and 67.24%higher than water control in germination rate, seedling height during 5-6 leaf stage and fresh weight on the ground. YN201408, YN201442 and YN201448 were classified into Bacillus amyloliquefaciens, and YN201458 into Pseudomonas aeruginosa based on their morphology, physiological and biochemical traits and 16S rDNA sequences. YN201448 showed good potential for application based on its growth promotion and disease control effect.
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