edda.lamyae@gmail.com

Bread wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is critical for food security, especially in Central and South Asia, North Africa, and Sub-Saharan Africa. Drought is having an increasing detrimental impact on bread wheat output as a result of climate change. In Morocco, a country primarily reliant on wheat production, drought has resulted in significant output losses over the last five years.

Over a century, researchers have investigated the use of plant growth-promoting rhizobacteria as an alternate technique for improving plant drought tolerance. Despite this understanding, the interaction of rhizobia with non-legumes was generally overlooked as a research topic until the last few decades.

Here we show that the application of Rhizobium as plant growth promoter under abiotic stress can have a positive effect on wheat yield components. Two elite wheat genotypes, one capable of withstanding drought and the other vulnerable to it, were primed with Three Rhizobium leguminosarum strains, and cultivated in plastic tunnels in the main growing season in Morocco under drought and well-watered conditions.

The strains were evaluated for their ability of phosphate solubilization (PSA) and phytohormones production under drought conditions. The application of the Rhizobium strains B1 and B2 had a positive effect on either wheat genotype. Under drought conditions, priming with these two Rhizobium strains led to an increase in seed number and number of tillers by 38% and 32%, respectively, compared to the uninoculated retrospective genotype. Interestingly, wheat genotypes act differently with the strains used for the inoculation.

The third Rhizobium strain (B3) had no effect on plant performance in the majority of the conditions, and multi-strain inoculation resulted in lower yield than when these micro-organisms were used alone allowing us to explore the genetic factors that control Rhizobium interactions with wheat in the future.