Isolation and characterization of endophytic plant growth-promoting bacteria (PGPB) associated to the sodicity tolerant polyembryonic mango (Mangifera indica L.) root stock and growth vigour in rice under saline sodic environment.
Kannan R., Damodaran T., Pandey B. K., Umamaheswari S., Rai R. B., Jha S. K., Mishra V. K., Sharma D. K., Sah V.
Author Affiliation: Central Soil Salinity Research Institute, Regional Research Station, Lucknow - 226 005, India.
African Journal of Microbiology Research 8 : 628-636
Abstract : In the recent times, there has been a reversed interest in the search of plant growth promoting endophytes (PGPE) for sustainable crop production. Mango is an economically important fruit crop, which is highly sensitive to saline environment. In the present study the importance of PGPR in growth promotion and their ability to elicit 'induced systemic tolerance' against abiotic (sodicity) stresses has been documented. Sixteen (16) putative of endophytic bacteria were isolated from sodicity tolerant polyembryonic mango root stock of GPL-3 and ML-4 from Shivari experimental farm, Central Soil Salinity Research Institute, Regional Research station, Lucknow, Uttar Pradesh, India. These endophytic bacteria were characterized using morphological and biochemical parameters and assessed for their plant growth promoting rhizobacteria (PGPR) traits like indole acetic acid (IAA) production, hydrogen cyanide (HCN) production, phosphate solubilization and siderophore production with 2.5 M NaCl concentration. The results based on specific biochemical characters revealed that the endophytic bacteria belonged to 14 different species and two uncultured organisms comprising five genera. Based on multifunctional properties under saline environment, four isolates were further selected to determine the PGP as vigor index of rice seedlings in pot culture experiments under saline sodic soils of pH 9.35 and EC 4.2. Of the bacteria tested, the isolate CSR-M-16 showed increased root and shoot length of rice followed by CSR-M-8, CSR-M-9 and CSR-M-6. The outcome of this research proves plausible practical applicability of these PGPB for crop production in saline sodic environment.