Isolation and screening of plant growth promoting rhizobacteria from rhizosphere of chilli

Abstract

In the present study PGPRB were isolated from agricultural field of chilli (Capsicum annum L.) Venbavur, Perambalur and characterized for plant growth promoting characteristics. Total number of bacteria in rhizosphere and non rhizosphere soil were 54 ± 1.73 x 106 cfu/g and 27± 2.0 x 106 cfu/g and the R/S ratio was found to be 2.0± 0.17x 106. The PSI index of three isolates VPGPRB1, VPGPRB4 and VPGPRB6 were 1.83 ± 0.06, 3.0 ± 0.46 and 2.45 ± 0.19, identified and confirmed to be Enterobacter sp., Bacillus sp. and Pseudomonas sp. The results of the evaluation of plant growth promoting characterisitcs showed that all the three isolates produced IAA, ammonia and exopolysaccharide (0.76 ± 0.15 mg/ml, 1.37 ± 0.25 mg/ml and 0.43 ± 0.08 mg/ml). The amount of IAA production were (10.6 ± 1.3µg/ml, 28.3 ± 0.66µg/ml and 19.1 ± 1.65µg/ml) and phosphate solubilization were (123 ± 1.5 μg/ml, 214 ± 1.8 μg/ml and 158 ± 1.74 μg/ml ) by Enterobacter sp., Bacillus sp. and Pseudomonas sp.