Characterization of multifaceted Bacillus sp. RM-2 for its use as plant growth promoting bioinoculant for crops grown in semi arid deserts

The rhizobacterial isolate RM-2 was characterized on the basis of sequencing of a partial 1270-bp fragment of 16S rDNA amplicon and validated as Bacillus sp. In view of using this strain as bioinoculant for sustainable agriculture in semi arid deserts, the plant growth promoting attributes were tested both in laboratory and field conditions. The isolate was found to have many beneficial attributes such as P solubilization, ACC deaminase activity, antifungal activity and ammonia and indole acetic acid production. The isolate positively influenced the growth and nutrient uptake of cowpea plants. Seeds coated with RM-2 showed a significant (P < 0.05) increase in seed germination, shoot and root length, fresh weight and dry weight, and leaf area. It was also able to colonize the rhizosphere of plants. Yield parameters such as number of pods and seeds and grain yield plant−1 were also enhanced significantly (P < 0.05) in comparison to control in pot and field trials in natural semi arid conditions. RM-2 strain can be considered as a good addition to consortium of beneficial microbes for growth promotion of cowpea plants.

► RM-2 was characterized as Bacillus sp. on the basis of sequencing of 16S rDNA.
► The isolate was found to have many beneficial growth promoting attributes in vitro.
► Seed bacterization showed significant increase in growth and yield of cowpea plants.
► Yield parameters such as number of pods and seeds and grain yield plant−1 were also enhanced significantly (P < 0.05) in comparison to control in pot and field trials in natural semi arid conditions.
► RM-2 has P solubilization, ACC deaminase activity and ammonia and IAA production.