Eggplant (Solanum melongena L.) associated endophytic bacteria promote plant growth and counter soil-borne plant pathogenic fungi

Abstract: The current study was aimed to isolate, identify and evaluate the potential endophytic bacterial strains inhabiting Solanum melongena L. for plant growth promotion (PGP) and biocontrol against important soil-borne plant pathogenic fungi. A total of 36 endophytic bacteria isolated from Solanum melongena L. (Eggplant) were characterized for qualitative PGP traits. Most promising strains SS_BS01, SS_BL08, SS_BL12 were identified using biochemical characteristics and 16S rDNA sequencing as Serratia marcescens (SS_BS01), Bacillus amyloliquefaciens (SS_BL08) and Pseudomonas sp. (SS_BL12) respectively. In addition, quantitative assays and antagonistic activities proved Bacillus amyloliquefaciens strain SS_BL08 efficient at all respects with maximum 145.8 ± 4.5µg mL-1(after 192 h) phosphate solubilization, 25.0 ± 1.6µg (5mg mL-1 L-tryptophan) IAA production and more than 60 % inhibition against selected phytopathogens. Furthermore, germination percentage, vigour index and seedling growth (root and shoot length) were also significantly increased. Selected endophytic bacterial strains of eggplant demonstrated promising results and Bacillus amyloliquefaciens strain SS_BL08, effective in promoting plant development and biocontrol, could be employed as bio-fertilizer and biocontrol agent for solanaceous crops in organic agriculture practice.