Bacillus- aided boron nutrition improves productivity of bread wheat (Triticum aestivum L.)

Abstract

Boron (B) deficiency can significantly impact wheat (Triticum aestivum L.) grain yield. Although B is present in soil upto 200 ppm but only 5% of it is available for the plants while the rest is in non-available form. However, some plant growth promoting rhizobacteria (PGPR), termed as B solubilizing bacteria, has the potential to augment B availability in the rhizosphere. Therefore, the present study was designed to investigate the effect of B application, with and without the use of B solubilizing bacteria (Bacillus MN54), on B availability, wheat performance and grain B concentration in two wheat cultivars (Faisalabad-2008 and Lasani-2008). Boron was applied to wheat through seed priming (0.01 M B), seed coating (250 mg kg^-1 seed), soil application (1.00 kg ha^-1) and foliar spray (0.01 M B), with hydropriming as control treatment. The results revealed that plants treated with Bacillus MN54 showed higher concentrations of organic acids in their root exudates, leading to improved wheat yield and grain B concentration. Furthermore, the combined application of B and Bacillus MN54 by various methods further improved the efficacy of the inoculant. Specifically, B and Bacillus MN54 application as seed priming resulted in the highest levels of organic acids in root exudates and grain yield (27%) followed by soil B + Bacillus MN54 application (25%) compared to control. Notably, the application of B and Bacillus MN54 as soil (21%) and foliar (23%) treatments yielded the highest grain B concentration. In conclusion, seed priming with B in combination with Bacillus MN54 has the potential to simultaneously improve wheat grain yield and grain B concentration.