Plant growth-promoting bacteria from the Thar desert for yield augmentation in wheat (Triticum aestivum L.)

About 33% of the Earth's landmass comprises deserts, where extreme abiotic stresses like heat, drought, and salinity hinder plant and microbial life. The Thar Desert, covering 91% of Rajasthan, harbours stress-resilient plant growth-promoting bacteria (PGPB) known to enhance plant development even under harsh conditions. In this study, we examined the bacterial isolates from sand dunes of the Thar Desert of India. Soil samples from three locations in the Thar Desert were used to isolate stress-tolerant PGPB, which were screened for multiple PGP traits and environmental resilience. Selected isolates were identified by 16S rRNA sequencing and evaluated through pot experiments for their impact on wheat growth and yield. Among a total of 37 culturable isolates, 7 isolates were identified for heat, salt and pH stress resilience as well as plant growth-promoting (PGP) activities. Among these seven potential bacterial isolates, four belonged to Bacillus spp., two belonged to Pseudomonas spp., and one was identified as Aeribacillus based on amplification and sequencing of the 16S rRNA gene. Upon inoculation of these potential microbial candidates with wheat variety DBW-187, a significant increase was recorded in growth and yield compared to control plants. However, two potential strains, BS-7 and BS34 (Bacillus subtilis; NCBI accession no OQ345974 and Pseudomonas sp.; NCBI accession no OQ345978) were found most promising in terms of plant growth and yield. These bioinoculants may become wonderful alternatives to chemical fertilisers.