Study on mating types and sensitivity to strobilurin fungicide in fungal wheat pathogen Mycosphaerella graminicola

Mycosphaerella graminicola, the causal agent of septoria tritici blotch (STB), is a widespread and significant pathogen of wheat. To determine mating types, ۸۹ isolates were collected randomly from wheat fields of Khuzestan, East Azerbaijan, Ardebil, Kermanshah and Golestan provinces of Iran, during ۲۰۰۶-۷. DNA was extracted based on standard protocols. Multiplex PCR was conducted using two pairs of mating type-specific primers for MAT۱-۱ and MAT۱-۲. Sensitivity to strobilurin fungicide was determined using strobSNPrc۷ and strobSNPrc۱ primers. The results showed that in ۳۵ isolates, a fragment of ۳۴۰ bp amplified with MAT۱-۱ idiomorph specific primers and in ۵۴ isolates a fragment of ۶۶۰ bp was amplified with MAT۱-۲ idiomorph specific primers. While the mating type frequencies were highly unequal, the MAT۱-۱ was predominant. All isolates were sensitive to strobilurin and amplified a fragment of ۶۳۹ bp. It is concluded that both mating types are present in Iran, although with different frequencies, which may affect genetic variation through sexual cycle. Meanwhile the studied isolates were not resistant to strobilurin fungicides which may be due to growing wheat cultivars resistant to STB rather than using strobilurin fungicides as a dominant control method.

کلیدواژه ها:

resistance ، Mat۱-۱ ، Strobilurin ، Zymoseptoria tritici