Abstract

Plant growth promoting rhizobacteria (PGPR) inhabit the rhizosphere region of plant and often found to be beneficial for the development and growth of plants. In this study, 17 pure isolates of bacteria from the rhizosphere of brinjal (Solanum melongena L.) and chilli (Capsicum annuum L.) were screened for their potential in growth promotion and antagonistic effect towards fungal pathogens of tomato plant (Solanum lycopersicum L.). Among the isolates, two bacterial strains (JB and JC) showed prominent activity and were further investigated. The selected bacterial isolates were identified as Pseudomonas aeruginosa and designated as P. aeruginosa JB and JC. Both the bacterial isolates enhanced the production of plant growth promoting compounds, such as phytohormones and salicylic acid. Seed inoculation with P. aeruginosa JB and JC also significantly improved the germination and growth of S. lycopersicum L. The bacterial strains were found to exhibit significant antagonistic effect towards the tested pathogens, Fusarium oxysporum and Alternaria solani. In the pot experiment, both the bacterial isolates P. aeruginosa JB and JC showed significant efficacy in decreasing the disease severity of test phytopathogens. These results suggested that both the rhizobacterial species could be further exploited as potential bio-inoculants for the improvement of plant growth, productivity and defence against phytopathogens.

摘要

植物生长促进根际细菌（PGPR）栖息在植物的根际区域，经常被发现对植物的发育和生长有益。本研究从茄子 ( Solanum melongena L.) 和辣椒 ( Capsicum annuum L.)的根际分离出 17 株纯细菌，以筛选出它们对番茄植物 ( Solanum lycopersicum L. ) 真菌病原体的促进生长和拮抗作用的潜力。 ）。在分离物中，两种细菌菌株（JB 和 JC）表现出显着的活性并被进一步研究。选定的细菌分离物被鉴定为铜绿假单胞菌并命名为铜绿假单胞菌JB和JC。这两种细菌分离物都增强了植物生长促进化合物的产生，例如植物激素和水杨酸。P.aeruginosa JB和JC的种子接种也显着改善了番茄的萌发和生长。发现该菌株对受试病原体尖孢镰刀菌和茄链格孢菌表现出显着的拮抗作用。在盆栽实验中，两种细菌都分离出铜绿假单胞菌JB 和 JC 在降低测试植物病原体的疾病严重程度方面显示出显着的功效。这些结果表明，这两种根际细菌都可以进一步用作潜在的生物接种剂，以改善植物的生长、生产力和抵御植物病原体。