The coupling effects of plant growth promoting rhizobacteria and salicylic acid on physiological modifications, yield traits, and productivity of wheat under water deficient conditions

Abstract

Water deficit and soil infertility negatively influence the growth, nutrient uptake, and productivity of wheat. Plant growth promoting rhizobacteria (PGPR) and salicylic acid (SA) were evaluated as possible solutions to mitigate the impacts of water deficit on growth, physiology, productivity, and nutrient uptake of wheat (Triticum aestivum L. cv. Sakha 95). Over two growing seasons (2016/2017 and 2017/2018) field experiments were conducted to examine eight combinations of two water treatments (water deficit and well-watered) with four soil and foliar treatments (control, PGPR, SA, and combination of PGPR + SA). The application of PGPR increased soil microbial activity resulting in increased field capacity and available soil water. Likewise, the application of the combined treatment of PGPR and SA significantly increased chlorophyll content, relative water content, stomatal conductance, soil microbial population, and showed inhibitory impacts on proline content, thus improving yield-related traits, productivity, and nutrient uptake (N, P, K) under water deficit compared to the control treatment. The results show that the integrative use of PGPR in association with SA may achieve an efficacious strategy to attenuate the harmful effects of water deficit as well as the amelioration of productivity and nutrient uptake of wheat under water-deficient conditions.