claudia.breitkreuz@julius-kuehn.de ; tim.kloppe@julius-kuehn.de ; kerstin.flath@julius-kuehn.de; philipp.schulz@julius-kuehn.de ; reif@ipk-gatersleben.de ; contreras@ipk-gatersleben.de ; andreas.stahl@julius-kuehn.de ; albrecht.serfling@julius-kuehn.de

With their broad host spectrum, rusts (Pucciniales) play a decisive role as obligate biotrophic fungi in agriculture. In wheat production in particular, yellow rust (Puccinia striiformis), leaf rust (Puccinia triticina) and, in future, stem rust (Puccinia graminis) due to climate change, cause considerable yield losses.

To reduce the infection level and at the same time avoid extensive use of fungicides, breeders invest massive effort in the development of wheat varieties with respective resistances. Despite, vertical resistance break downs occur regularly as a consequence of adaption of the pathogen, but also as a lack of knowledge in temporal and spatial occurrences of rust races with distinct virulence/avirulence pattern.

In the project RustHealth, we aim to address specifically this lack of knowledge by investigating plant-pathogen-interactions at 13 different locations across Germany in three consecutive years. In the first year, infection by stripe and leaf rust is documented for in total 200 wheat varieties selected from German elite cultivars and genebank accessions. These field trials are complemented with infection incidences of different rust races, e.g. Warrior(-) for stripe rust and 77 WxR for leaf rust, measured by the Macrobot platform under controlled conditions.

The comparison of controlled and field conditions at the 13 different locations will indicate environment dependent effects on infection patterns. In parallel, leaves from infected plants are collected to investigate spatial patterns of rust race occurrences. Overall, these datasets will be compiled to model genotype rust x genotype wheat x environment relationships.

In contrast to stripe and leaf rust, stem rust is artificially inoculated to check for unknown resistance loci in plant genetic resources. Overall, this project contributes to a better understanding of plant-pathogen-interactions strengthening breeding efforts by the development of markers, breeding material and knowledge about the biochemical background of resistances against rusts in wheat.