In the present study, a total of 68 endophytic bacteria were isolated from different tissues of walnut trees. About 55% and 22% of the strains had the ability to produce indole acetic acid and gibberellic acid, respectively. The capability of isolates to solubilize phosphate, growth on N-free medium, siderophore, protease and lipase production was varied. Based on phenotypic grouping and plant growth promotion properties, twelve isolates were selected and 16S rRNA gene-based phylogenetic analysis revealed that strains showed 99-100% similarity to Pseudomonas, Bacillus, Arthrobacter, Roseomonas and Streptomyces genus. Amongst the selected strains, PS12, KS54, JS66 and KS74 showed root and shoot growth enhancement of poplar cutting. NS70, KS54 and PL36 strains showed antagonistic activity against Pseudomonas syringae pv. syringae, RR47,KS74 and NR69 strains had inhibition effects against Brenneria nigrifluens, and JS66 and RR26 strains had antagonistic activity against both phytopathogens. This is the first reported study to elucidate the endophytic bacterial diversity associated with walnut trees with beneficial attributes.
