This study was conducted with barley in greenhouse conditions in order to investigate seed inoculation with 5 different N2-fixing (Bacillus licheniformis RC02, Rhodobacter capsulatus RC04, Paenibacillus polymyxa RC05, Pseudomonas putida RC06, and Bacillus OSU-142) and 2 different phosphate-solubilising (Bacillus megaterium RC01 and Bacillus M-13). | Turk J Agric For 31 (2007) 189-199 © TÜB‹TAK The Effect of Plant Growth Promoting Rhizobacteria on Barley Seedling Growth, Nutrient Uptake, Some Soil Properties, and Bacterial Counts Ramazan ÇAKMAKÇI1,2,*, Mesude Figen DÖNMEZ3, Ümmügülsüm ERDO⁄AN2 1 Atatürk University, Biotechnology Application and Research Centre, 25240 Erzurum - TURKEY 2 Atatürk University Technical Vocational School, ‹spir, 25900 Erzurum - TURKEY 3 Atatürk University Faculty of Agriculture, Department of Plant Protection, 25240 Erzurum - TURKEY Received: Abstract: This study was conducted with barley in greenhouse conditions in order to investigate seed inoculation with 5 different N2-fixing (Bacillus licheniformis RC02, Rhodobacter capsulatus RC04, Paenibacillus polymyxa RC05, Pseudomonas putida RC06, and Bacillus OSU-142) and 2 different phosphate-solubilising (Bacillus megaterium RC01 and Bacillus M-13) bacteria in comparison to control and mineral fertiliser (N and P) application. Among the strains used in the present study, 6 plant growth promoting rhizobacteria (PGPR) stimulated indole acetic acid (IAA) production and 3 of them stimulated phosphate solubilisation; all bacterial strains fixed N2 and significantly increased the growth of barley. Available phosphate in soil was significantly increased by seed inoculation with Bacillus M-13 and B. megaterium RC01. Maximum NO3-N was found in soil after inoculation with N2-fixing Bacillus OSU-142, followed by P. polymyxa RC05 and R. capsulatus RC04. Total culturable bacteria count increased in all treatments with time, whereas N2-fixing bacteria decreased with time, except with B. megaterium RC01 inoculation. The data suggest that seed inoculation of barley with plant PGPR increased root weight by as compared to the control, and increased shoot weight by , depending on the species. N2-fixing bacterial inoculation significantly increased uptake of N, Fe, Mn, and Zn by barley. The production of hormones is
