Both mating types of the wheat pathogen Mycosphaerella graminicola are present in Morocco

Septoria tritici blotch caused by the heterothallic ascomycete Mycosphaerella graminicola is one of the most currently damaging diseases on wheat crops worldwide. So far, no information was reported about the status of sexual reproduction of this pathogen under Moroccan conditions. We investigated here for the first time the occurrence of the two mating types (MAT1-1 and MAT1-2) of M. graminicola in Morocco by sampling 141 single-conidial isolates from 4 important wheat producing regions (Gharb, Saïs, Chaouia and Tadla). The mating type of each isolate was determined by amplification with multiplex PCR of a partial sequence from the corresponding idiomorph. Overall, 43% out of the assessed isolates were MAT1-1 and 57 % were MAT1-2. Both mating types were identified within the 3 sampled regions Gharb, Saïs and Chaouia, but not in Tadla, where only MAT1-2 isolates were found. The presence of the two mating types highlighted here offers a suitable genetic condition for M. graminicola to occur sexual reproduction in Morocco. The potential of sexual recombination will be examined by the study of mating type frequencies using a large sample size as well as by searching and quantification of pseudothecia in the field.