Plant growth promoting Bacillus -based bio formulations improve wheat rhizosphere biological activity, nutrient uptake and growth of the plant

Rhizospheric bacteria possess the potential to colonize the root zone of plants and stimulate their growth through different mechanisms. The present study explored the competency of plant growth promoting rhizobacteria based bioformulations ( bf ) formed from Bacillus pumilus (BP- bf ), Bacillus simplex (BS- bf ) and Bacillus megaterium (BM- bf ) on the growth, yield and nutrient status of two wheat genotypes ( Raj 3765 and DBW 90 ). In vitro studies demonstrated that biopriming with bf significantly improves the vigor index and germination of seedlings whereas results varied with different bacterial bioformulations. A pot experiment for further validation of results was conducted in factorial design with these treatments: T1: control of DBW 90 ; T2: control of Raj 3765 ; T3: DBW 90 bioprimed with BP- bf ; T4: Raj 3765 bioprimed with BP- bf ; T5: DBW 90 bioprimed with BS- bf ; T6: Raj 3765 bioprimed with BS- bf ; T7: DBW 90 bioprimed with BM- bf ; T8: Raj 3765 bioprimed with BM- bf . Results demonstrated that bf applied treatments exhibited significant ( P ≤ 0.01) improved growth and yield over control. The grain yield ranged 3.48 to 6.61 g/pot in bf applied treatments and significantly ( P ≤ 0.01) increased straw weight was also obtained in these treatments. Amongst all bioformulations, BM- bf triggered the highest growth and yields in both the wheat genotypes. Results also demonstrated that these bioformulations induced the nutrient uptake in both wheat genotypes. Wheat rhizospheric biological activity was also boosted by the application of these bioformulations as significantly ( P ≤ 0.001) enhanced bacterial colonization and microbial enzymatic activities were found. The study advocates the ability of these plant growth promoting Bacillus based bioformulations to improve the growth, quality and productivity of different wheat genotypes.