Preliminary essay on the aggressiveness of Pyrenophora tritici-repentis towards five Tunisian varieties of durum wheat (Triticum durum). Tissaoui, S., Kamel, S., Mougou-Hamdane, A., Chérif, M., and Nasraoui, B. (Tunisia)

This preliminary study aimed to evaluate reaction of fiveTunisian commercial varieties of durum wheat against six populations of Pyrenophora tritici-repentis (Ptr), the causal agent of tan spot, collected from different Tunisian northern regions. Seedlings were sown in growth chamber and inoculated by foliar spray of Ptr suspension. The reactions of durum wheat varieties were evaluated 10 days postinoculation based on necrosis and/or chlorosis severity on leaves. This assessment revealed symptoms of variable intensity on wheat seedlings, with populationsP1 and P6 three times more aggressive than population P5. The variety behavior was quite similar, however Salim followed by Maali were found be the most susceptible ones and Nasr was the most relatively resistant.