Contacts: Sepideh.jafarian@helmholtz-munich.de

Wheat farming, dating back millennia, prioritizes yield and disease resilience. Climate change now endangers winter wheat stability, emphasizing “drought resistance”. This trait varies among wheat varieties and populations, depending on intrinsic and extrinsic factors. Identifying key genes and molecular factors is crucial for marker availability and breeding resilience.

The Dry-Wheat project utilizes the Bavarian Magic Wheat population (BMW) to study drought stress resistance diversity and pinpoint associated genes and markers in modern bread wheat (Triticum aestivum) varieties. The project employs δ13C/12C isotope composition as a physiological measure of intrinsic water use efficiency (iWUE) to identify wheat lines that are more resistant to drought stress. This project systematically investigates the variability in drought resistance of the relevant elite breeding material.

In this experiment, ten extreme genotypes selected from nearly four hundred lines based on their δ13C/12C, divided into high and low groups. Extensive phenotyping trials, consisting of 20 replications per genotype and two conditions of drought stress and control, were carried out at the Helmholtz Center. Relevant parameters such as dry biomass, plant height, leaf area etc. were systematically determined both automatically (using Phenospex system) and manually, and then compared. In the anthesis stage, flag leaves were collected for RNA sequencing. Statistically significant differences for desired traits were observed between the two conditions both for different genotypes as well as for the δ13C groups.

We performed a differential gene expression analysis (DEG) to identify candidate genes in our two experimental conditions. We observed pronounced differences between the two δ13C groups under drought conditions, where the number of up and down regulated genes were found significantly higher in the group of low δ13C s.

In a next step, these expression data will be analyzed in correlation with the results from the phenotyping experiments and the isotope discrimination measurements.

This project is financed by the Bavarian State Ministry of the Environment and Consumer Protection in the frame of the project network BayKlimaFit 2.