بررسی حضور ژن تولید کننده‌ی نکروز (ToxA) در جدایه‌های عامل بیماری لکه‌خرمایی گندم در استانهای مازندران و گلستان

The tan spot disease is caused by the fungal wheat pathogen Pyrenophora tritici-repentis. The successful use of resistant cultivars depends on sufficient information about the pathogen genetic structure particularly the presence/absence of virulence factors within the fungal populations. The present study were carried out to determine the distribution and frequency of the ToxA producing gene in tan spot fungal populations. To this aim, after sampling of the wheat infected leaves, fungal isolation, purification and propagation, DNAs from P. tritici-repentis were isolated. The DNA samples were screened using specific primers for detection of ToxA gene. The results showed that about 85% of the isolates possess ToxA gene. Based on these results, most of the tan spot isolates collected from Mazandaran and Golestan provinces. This study showed that necrosis induced by this pathogen can be attributed to the high frequency of this gene in the fungal populations.