Jean-Louis Hilbert, A. Yahyaoui, M. Hassine, Anne Legrève, Maxime Duvivier, T. Cadalen, W. Hamada, P. Halama, Pierre Hellin, A Siah, M. Baraket, Université de Tunis Carthage, Institut Charles Viollette (ICV) - EA 7394 (ICV), Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de la Recherche Agronomique (INRA)-Université d'Artois (UA)-Institut Supérieur d'Agriculture, Université Catholique de Louvain = Catholic University of Louvain (UCL), Centre Wallon de Recherches Agronomiques (CRA-W), National Water Research Institute, International Maize and Wheat Improvement Center (CIMMYT), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Laboratory of Genetics and Cereal Breeding at the National Agronomic Institute of Tunisia (INAT), Regional Field Crops Research Center - Tunisia, Tunisia Septoria Phenotyping Platform of CIMMYT - Tunisia, Walloon Agricultural Research Center - Belgium, Earth and Life Institute of the Catholic University of Louvain - Belgium, European UnionEuropean Union (EU), French Regional Council Hauts-de-France, Institut Charles Viollette of Lille - France, UCL - SST/ELI/ELIM - Applied Microbiology, and Université d'Artois (UA)-Institut National de la Recherche Agronomique (INRA)-Université du Littoral Côte d'Opale (ULCO)-Institut Supérieur d'Agriculture-Université de Lille
International audience; Septoria tritici blotch (STB) caused by the heterothallic ascomycete Zymoseptoria tritici is currently one of the most devastating diseases of wheat worldwide. The extent of sexual reproduction of this pathogen is well documented on bread wheat, but not on durum wheat. The objective of the present study was to quantify the occurrence of Z. tritici sexual reproduction on durum wheat in the Tunisian environment. The assessment was undertaken using a triple approach combining fruiting body assessment, ascospore trapping and population genetic analyses. The results highlighted the formation of pseudothecia on leaves and stubble from the autumn until the end of the growing season. Likewise, qPCR monitoring highlighted a constant release of Z. tritici airborne inoculum during the wheat-growing season, with a peak of production at the end of the season. Genetic investigations using microsatellites revealed high levels of gene and genotypic diversities, an equal distribution of mating types, and a lack of genetic clustering within and between growing seasons. Taken together, these findings indicate that Z. tritici undergoes sexual reproduction on durum wheat in Tunisia at least to the same extent than on bread wheat in Western Europe, and that the dry and warm climate does not affect the mating process of the fungus. Frequent occurrence of sexual reproduction is a valuable knowledge to take into account in STB control strategies on durum wheat. (C) 2019 British Mycological Society. Published by Elsevier Ltd. All rights reserved.