The role of gene flow in rapid adaptation of fungal plant pathogen

Alice Feurtey, Postdoc in HO 4435/1-1

Pyrenophora teres is a necrotrophic fungal pathogen of plants and can infect important crops including barley. This pathogen is considered an emerging disease in countries such as Germany which is the first producer of barley in Europe (Eurostat). On barley, P. teres can cause severe damages resulting in 10 to 40% of yield loss. Two forms of P. teres are responsible for net blotch: P. teres f. teres and P. teres f. maculata. These two forms are morphologically indistinguishable but cause different lesions on leaves: lattice-like symptoms for the teres form and ovoid lesions for the maculata form. These two forms are also genetically distinct to the point that some authors propose to consider them as two species. However, hybridization between them has been detected in natural environment and hybridization can be induced under artificial conditions. Part of the hybrid progeny from P. teres crosses was even found to be virulent on barley lines resistant to both parents. Based on these previous studies, we hypothesize that hybridization could play a role in rapid adaptation of P. teres and we propose to test this hypothesis using genomic data.