Selection of alkalotolerant and symbiotically efficient chickpea nodulating rhizobia from North-West Indo Gangetic Plains

In an effort to obtain reliable, alkali-tolerant, and symbiotically efficient rhizobial strains, 54 indigenous rhizobial isolates were obtained from root nodules of chickpea grown in alkaline soil of 5 different agricultural locations in North-West Indo Gangetic Plains (NW-IGP). Of these, 16 most symbiotically effective isolates were selected for polyphasic analysis (pH stress, salt tolerance, and genetic characterization). All the selected isolates were able to tolerate the high alkaline pH. Among them, CPN1, CPN8, and CPN32 grew well at pH 11.0. High pH-induced proteins were explored by SDS-PAGE assay. Identification and genetic characterization of isolates was done by 16S rRNA gene sequencing, RNA polymerase subunit-B (rpoB) and symbiotic genes (nodC and nifH). The study revealed diverse symbiotically efficient alkalotolerant chickpea nodulating rhizobial strains from NW-IGP. This study has thus contributed a valuable genetic pool of isolates that can potentially be used to increase chickpea production in these soil types.