In pigeonpea due to the prevailing high temperature, poor nodulation have usually been observed as a limiting factor in its productivity. Plant growth promoting traits of 5 pigeonpea rhizobacterial isolates out of 32, selected on the basis of maximum growth at 30, 40 and 50Â°C, were evaluated for their potential application in enhancing symbiosis and plant growth of pigeonpea. The level of IAA at 30, 40 and 50Â°C varied from 0.95-20.96 Î¼g/ml, 1.21- 34.82 Î¼g/ml and 0.16-17.34 Î¼g/ml in the presence of tryptophan respectively. Maximum flavonoid production and siderophore production was recorded bacterial isolates with S12p6 (6.68 Î¼g/ml) at 30Â°C and S1p1 (4.2 cm) at 40Â°C respectively. Isolates S1p1 and S12p6 showed relatively superior production of growth hormone, flavonoid-like compounds and siderophores can further be tested as co-inoculant with recommended Rhizobium for studying their efficacy under field conditions for symbiotic parameters and growth of pigeonpea.
Pigeonpea, PGPRs, Rhizobacteria, Rhizobium
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