First report on Rahnella sp. strain EU-A3SNfb, a plant growth promoting endophytic bacterium from wild wheat relative Aegilops kotschyi

Endophytic biology is an emerging field due to their wide range of application in various sectors including agriculture, pharmaceutical, medical, and industries. The endophytic phytomicrobiomes residing inside the tissue of the plant have gained the momentum for plant growth promotion (PGP), crop production and protection along with sustaining the environmental health. Considering the importance of sustainability, the present study aimed to characterize and evaluate the plant growth promoting endophytic microbes with nitrogen fixing ability. A total of 52 putative endophytic bacteria were isolated from wild wheat relative Aegilops kotschyi growing in the Himalayan regions. All the isolates were screened for nitrogen-fixing attributes, and the selected nitrogen fixing bacteria were screened for other PGP attributes including solubilizing of phosphorus, potassium and zinc; production of siderophores, ammonia and hydrogen cyanide. Efficient microbe having capability to fix nitrogen was identified as Rahnella sp. strain EU-A3SNfb using 16S rRNA gene sequencing and BLASTn analysis. The selected bacterial strain was evaluated for growth of Aegilops kotschyi, and results showed the significant improvement in the physiological parameters, chlorophyll, total soluble sugar, phenolics and flavonoid content as compared to recommended dose of chemical fertilizer and untreated control. This efficient bacterial strain EU-A3SNfb could be used as bioinoculants for cereal crops growing in hilly region for agricultural sustainability.