Effect of Rhizobacteria on Plant Growth of Different Vegetables

The objective of this study was to evaluate possible effects of different strains of plant growth promoting rhizobacteria -PGPR- on growth of cucumber, pepper and tomato. Six bacterial strains from the collection of the Department of Plant Protection, Agricultural Faculty of Ege University (18/1K: Pseudomonas putida, 21/1K: Enterobacter cloacae, 62: Serratia marcescens, 70: Pseudomonas fluorescens, 66/3: Bacillus spp., 180: Pseudomonas putida) were compared with two commercial products (Bacillus amyloliquefaciens FZB24, Bacillus amyloliquefaciens FZ1342) and control (without bacteria inoculation). Native PGPR strains were assayed for their ability to produce IAA and phosphate solubilization in vitro. IAA production varied between 0.700 and 0.065 pg ml(-1). Native isolates excluding Bacillus spp. strain 66/3 had phosphate solubilization ability. Rhizobacteria were tested in vivo to determine their effects on seedling growth. The results indicated significant increases in growth of cucumber, tomato and pepper in response to inoculation with PGPR. According to the results of in vitro and in vivo tests, 18/1K, 62, 70 and 66/3 were selected as promising strains among the isolates of Ege University for future studies.