Archivio Journal of Plant Pathology

Abstract:

Mycosphaerella graminicola is a heterothallic ascomycete responsible for Septoria tritici blotch, the most frequently reported disease on wheat crops over the last decade. A set of 230 monoconidial isolates of this pathogen were obtained from six wheat-producing regions of Morocco and assayed by multiplex PCR to assess the mating type distribution and provide insight into the occurrence of sexual reproduction in this country. Both mating types were identified on bread wheat and durum wheat and found to occur at different rates throughout the country. At the whole country level, 44% of the assessed isolates were MAT1-1 and 56% were MAT1-2. Both mating types were found in each surveyed areas, with equal frequencies in Chaouia, Meknes-Tafilalet, Tadla-Azilal and Doukkala-Abda but not in Gharb and Fes-Boulmane. At the finer scale, both idiomorphs were identified together on 37% of the leaves and on 23% of the lesions from which multiple isolates were recovered. The overall co-occurrence of the two mating types suggests that sexual recombination of M. graminicola might be frequent in Morocco and most likely plays a major role in the epidemiology and the evolution of the pathogen in this country.