Determination of mating type idiomorphs of Pyrenophora graminea isolates, the causal agent of barley leaf stripe in northwest of Iran

Barley leaf stripe caused by the fungus Pyrenophora graminea, is one of the most important and devastating barley diseases in Iran. A total of 121 P. graminea isolates was recovered from cultivated barley in West Azerbaijan (Miyandoab region), East Azerbaijan (Miyaneh region), Ardebil (Ardebil region) and Zanjan (Khorramdareh region) provinces in 2016. After morphological and molecular identification, mating type primers were designed based on a conserved DNA binding (alpha domain) in MAT-1 and the high mobility group (HMG) domain in MAT-2. Frequency of mating type idiomorphs of P. graminea isolates were done by Multiplex PCR. Among 121 isolates, 56 isolates amplified by MAT-1 primer and 65 isolates by MAT-2 primer. Frequencies of two mating types in Khorramdareh (1) and Miyandoab populations had an excess of the MAT-1 and MAT-2 alleles, respectively. According to the results of the Chi-square test (X2), Miyaneh, Ardebil (1 and 2) and Khoramdareh (2) populations had not significant difference in compared with Khorramdareh (1) and Miyandoab populations. Therefore, these four populations have the highest potential for sexual reproduction than the two populations of Miyandoab and Khorramdareh (1). In addition, isolates from all of the populations were studied to evaluate the sexual fertility through directed crossing with opposite mating types. After six months, pseudothecia formed in media without mature asci and ascospores.