Visiting Scientist Seminar – Professor Andreas Stahl

Abstract

This seminar will be presented in two parts, as described below.

Part 1) Improving resistance to fungal pathogens in order to reduce the use of fungicides

In addition to abiotic stress, phytopathogenic fungi remain major constraints of wheat production in Europe with substantial impact on grain yield. Among them stripe and leaf rust, powdery mildew and various Fusariumspecies are the most relevant pathogens of wheat in Europe, but also worldwide. To assess breeding progress over the past five decades, within the BRIWECS project the resistance level of 191 wheat cultivars, which were economically important in the period following their cultivar release, and, hence, represent the breeding history of winter wheat in Western Europe, were assessed in detail in field trials for three consecutive years.

In order to continue the genetic gain in resistances into the future conditions it will be necessary to exploit resistances from genetic resources such as land races and crop-wild relatives to be introgressed and pyramidized in elite lines together with already introduced long-term durable quantitative resistances. For this purpose, at JKI and partner institutions we regularly assess the resistance status of large diversity panels against leaf and stripe rust isolates in order to identify potential resistance donors. By bringing together high-throughput phenotyping technologies, the availability of full genome sequence information and the use of the latest statistical methods, there is reason to assume that the resistance level of the varieties can be further increased.

Part 2) Identification of genotypic variation for diurnal and developmental stage-specific transpiration patterns under drought stress conditions in wheat

When breeding for drought stress tolerance, context is key: depending on timing, length and intensity of a drought period different traits may contribute to an enhanced drought tolerance, and the crop’s drought stress response may differ among developmental stages.

In this study, developmental stage-specific transpiration efficiency and transpiration response to increasing VPD in a set of 79 elite winter wheat lines was evaluated using the custom-built “DroughtSpotter XXL” facility.

The resulting high-resolution data enabled the identification of significant developmental stage-specific variation for genotype rankings in transpiration efficiency. In addition, a breakpoint in transpiration in response to increasing VPD was identified in all examined genotypes, with breakpoints ranging between 2.7 and 4.1 kPa

Continuous monitoring of transpiration efficiency and diurnal transpiration patterns along with the impact of these traits on yield performance under drought stress conditions enabled us to identify hidden genotypic variation for potentially beneficial transpiration traits.

About the speaker