Plant growth-promoting bacteria effect in withstanding drought in wheat cultivars

Abstract

This work evaluated wheat genotypes under water deficit inoculated with Azospirillum brasilense and Herbaspirillum seropedicae, with and without nitrogen fertilization. Samples of the plants were collected to evaluate its relative water content (RWC) and membrane stability index (MSI) at the 1st and 8th day of total water restriction at the booting stage. The plant biomass, total nitrogen (TN) and grain yield were determined at harvesting. The genotypes showed different performances. According to the results of RWC and MSI, inoculation with A. brasilense and H. seropedicae can make the cultivar CD-120 more tolerant to drought. Grain index was improved with H. seropedicae in all conditions and water regimes. H. seropedicae with nitrogen fertilization increased grain yield under water deficit. A. brasilense with nitrogen fertilization improved the 1000-grain weight of plants under water deficit. The cultivar Frontana maintained its cellular integrity and RWC with nitrogen fertilization combined with H. seropedicae and with both bacteria, however the shoot and root fresh and dry weights, TN and yield of this cultivar showed no differences. These results show the inoculation with H. seropedicae as promising to cereals, and the cultivar CD-120 as a good plant model to study plant-bacteria interaction.