Assessing phosphate solubilization ability of sesbania grandiflora rhizobia isolated from root nodules using diverse agroecological zones of Indian soils for biofertilizer production

Abstract

A total of 20 rhizobia were isolated from Sesbania grandiflora root nodules by using trap plant method from diverse agroecological zones of Indian soils. These rhizobial isolates produced round, whitish, smooth surfaces on YEMA medium plates and were short rod in shape, motile in nature and gram negative in reaction. On Pikovskaya’s medium plates around 80% of rhizobial isolates were found to be phosphate solubilizers. P-solubilisation index (P-SI) of these isolates ranged from 1.96 to 4.85. In the present investigation, isolates SGBh from Bhadra (Rajasthan) and SGKr(ii), SGKr(iv), SGKr(v) from CSSRI, Karnal (Haryana) were found to have excellent P-solubilization ability and can be exploited as biofertilizers for better yield of Sesbania grandiflora.