Isolation and Characterization of Plant Growth Promoting Rhizobacteria (PGPR) and Their Effects on Improving Growth of Wheat

Abstract

Plant Growth Promoting Rhizobacteria (PGPR) is commonly used as an inoculants for improving the growth and yield of agricultural crops. So, screening for the selection of effective PGPR strains is very critical. In this study, 180 bacteria were isolated from the rhizosphere of different wild plants collected from the vicinity of Erzurum and Kırsehir, Turkey. These isolates were tested for their nitrogen fixing (NF) and Phosphate Solubilizing (PS) capacity. Sixteen isolates were found to have both NF and PS potential at different levels and designated as AS1, AS2, AS3…AS16). These 16 isolates were also analysed in their auxin (IAA) and ACC deaminase production potentials. To investigate the effects of PGPR isolates on the growth of spring wheat (Triticum aestivum L.) a pot and a field experiment was conducted. According to the results of pot experiments only the most effective six isolates were tested at field trials and after harvest, some growth and yield parameters were analysed. Results showed that 6 isolates (AS1, AS3, AS4, AS6, AS8 and AS15) have significant (P<0.05) positive effect on plant height, dry matter and protein content. On the basis of some cultural, cytological characteristics and fatty acid profiles, these effective isolates were identified as Cellulomonas turbata (AS1), Pseudomonas putida (AS3), Bacillus cereus (AS4), Enterobacter cloacae (AS6), Bacillus megaterium (AS8) and Bacillus megaterium (AS15). As a result, it can be said that inoculation of wheat with this strains may lead both the increases in yields and substitute costly nitrogen-phosphate fertilizer in wheat production.