Strategies to protect cereals from climate-induced increases in fungal diseases

Global climate change will also pose new challenges to German cereal production in terms of resistance to biotic stress. It is expected that some pathogens will be favoured by milder winters and warmer summers, e.g. yellow rust, Fusarium head blight, while other pathogens may become newly epidemic, e.g. stem rust. In addition to rusts, some mycotoxin-producing pathogens of Fusarium head blight are also favoured by warming. The complex structure of stem rust and the rapid change of yellow rust strains, as well as alarming reports of stem rust outbreaks in Sicily in 2016 and Sweden in 2017, show that monitoring these wind-borne pathogen populations is important (WP1). In WP2, new sources of resistance will be identified by association mapping on a pre-selected wheat panel (280 genotypes) and an unselected triticale panel (1000 genotypes), and five identified carriers of stem and yellow rust resistance in wheat, each with 92-140 progeny, will be analysed by QTL mapping. Effective qualitative and quantitative resistance mechanisms will be tested by artificial infection at the adult plant stage using multiple phenotyping. Genomic regions will be identified for direct use by breeders. The efficiency of marker-assisted selection will be compared with that of genomic selection. As breeding is a lengthy process, fungicide strategies to control stem rust need to be investigated to secure yields in the short term. In WP3, the efficacy of fungicides will be tested in greenhouse and field trials as a function of temperature, cultivar and time of application to identify potent agents to control stem rust.