This study was carried out to explore a non-chemical strategy for enhancing productivity by employing some antagonistic rhizobacteria. One hundred eighteen bacterial isolates were obtained from rhizospheric zone from various crop fields of Gangwon-do, Korea, and screened for antifungal activity against Fusarium wilt (Fusarium oxysporum f. sp. lactucae) in lettuce crop under in vitro and in vivo conditions. In broth-based dual culture assay, fourteen bacterial isolates showed significant inhibition of mycelial growth of F. oxysporium f. sp. lactucae. All of the antagonistic isolates were further characterized for the antagonistic traits under in vitro conditions. The isolates were identified on the basis of biochemical characteristics and confirmed at their species level by 16S rRNA gene sequencing analysis. Arthrobacter sulfonivorans, Bacillus siamensis, Bacillus amyloliquefaciens, Pseudomonas proteolytica, four Paenibacillus peoriae and Bacillus subtilis were identified from the biochemical characterization and 16S rRNA gene sequencing analysis. The isolates EN21 and EN23 showed significant decrease in disease severity on lettuce compared to infected control and other bacterial treatments under greenhouse conditions. Two bacterial isolates, EN4 and EN21, were evaluated to assess their disease reduction and growth promotion in lettuce in field conditions. The consortium of EN4 and EN21 showed significant enhancement of growth on lettuce by suppressing disease caused by F. oxysporum f. sp. lactucae respectively. This study clearly indicates that the promising isolates, EN4 (P. proteolytica) and EN21 (Bacillus siamensis), can be commercialized and used as biofertilizer and/or biopesticide for sustainable crop production.

中文翻译：

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抑制尖孢镰刀菌引起的枯萎病。 sp。使用细菌分离物促进生菜生长。


本研究的目的是探索利用一些拮抗性根际细菌来提高生产力的非化学策略。从韩国江原道不同作物田的根际区获得了 118 个细菌分离株，并在体外和体内条件下筛选了对生菜作物中镰刀菌枯萎病（ Fusarium oxysporum f. sp. milkucae ）的抗真菌活性。在基于肉汤的双重培养测定中，14 种细菌分离株显示出对 F. oxysporium f 菌丝体生长的显着抑制。 sp。莴苣科。所有拮抗分离株在体外条件下进一步表征拮抗特征。根据生化特征对分离株进行鉴定，并通过 16S rRNA 基因测序分析在物种水平上进行确认。通过生化表征和16S rRNA基因测序分析，鉴定出食磺节杆菌、暹罗芽孢杆菌、解淀粉芽孢杆菌、解蛋白假单胞菌、四种类芽孢杆菌和枯草芽孢杆菌。与受感染的对照和温室条件下的其他细菌处理相比，分离株 EN21 和 EN23 的生菜疾病严重程度显着降低。对两种细菌分离株 EN4 和 EN21 进行了评估，以评估它们在田间条件下对生菜的疾病减少和促进生长。 EN4 和 EN21 的联合体通过抑制F引起的疾病，显着增强生菜的生长。尖孢菌F. sp。分别是莴苣。这项研究清楚地表明有前途的分离株 EN4 ( P. proteolytica）和EN21（暹罗芽孢杆菌）可以商业化并用作可持续作物生产的生物肥料和/或生物农药。