International Symposium on Cereal Leaf Blights 2019 | University College Dublin, Ireland | 22-24 May 2019

Airborne inoculum, fruiting body and genetic structure monitoring provides evidencefor active sexual reproduction of Zymoseptoria tritici on durum wheat


Marwa Hassine*
Laboratory of Genetics and Cereal Breeding, National Agronomic Institute of Tunisia, Avenue Charles Nicolle 43, 1082 Tunis, Tunisia

Ali Siah
EA 7394, USC INRA 1411, Institut Charles Viollette, Agro-food and Biotechnology Research Institute, Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d’Opale, 59000 Lille, France

Pierre Hellin
Plant Protection and Ecotoxicology Unit, Walloon Agricultural Research Center, Rue du Bordia 11, 5030 Gembloux, Belgium

Thierry Cadalen
EA 7394, USC INRA 1411, Institut Charles Viollette, Agro-food and Biotechnology Research Institute, Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d’Opale, 59000 Lille, France

Patrice Halama
EA 7394, USC INRA 1411, Institut Charles Viollette, Agro-food and Biotechnology Research Institute, Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d’Opale, 59000 Lille, France

Jean-Louis Hilbert
EA 7394, USC INRA 1411, Institut Charles Viollette, Agro-food and Biotechnology Research Institute, Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d’Opale, 59000 Lille, France

Walid Hamada
Laboratory of Genetics and Cereal Breeding, National Agronomic Institute of Tunisia, Avenue Charles Nicolle 43, 1082 Tunis, Tunisia

Mokhtar Baraket
National Research Institute of Rural Engineering, Water and Forestry, Rue Hédi EL Karray El Menzah IV, 1004 Tunis, BP10 Ariana, 2080, Tunisia

Amor Yahyaoui
International Maize and Wheat Improvement Center, Carretera México-Veracruz Km. 45, El Batán, C.P. 56237 Texcoco, México.

Anne Legrève
Applied microbiology, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 2 box L7.05.03, 1348 Louvain-la-Neuve, Belgium

Maxime Duvivier
Plant Protection and Ecotoxicology Unit, Walloon Agricultural Research Center, Rue du Bordia 11, 5030 Gembloux, Belgium


Oral Presentation
Cultural Management, Fungicide Resistance and Epidemiology

Moore Auditorium, UCD O'Brien centre for Science
22 May 2019, 15:40

View this abstract online by visting isclb2019.com/see/ABS33482

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 potential 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 genic and genotypic diversities, an equal distribution of mating types and a lack of genetic clustering within and between growing seasons. Taken together, these findings agree in suggesting strong potential for sexual reproduction on durum wheat in Tunisia for Z. tritici. Interestingly, the frequencies of detection and the quantities of trapped spores in Tunisia under low STB pressure on durum wheat are comparable to those previously found under severe STB pressure on bread wheat in Western Europe. This suggests that Z. tritici sexual reproduction in the Tunisian environment should occur to the same extent than Western Europe or could even be more important in epidemics. Such findings could explain the recurrence of strong STB epidemics in Tunisia and could be a valuable factor to take into consideration in STB management programmes on durum wheat.