R. Rodeva1*, S. Nedyalkova2, Z. Stoyanova1

1Department of Applied Genetics and Plant Biotechnology, Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, 21 Acad. G. Bonchev, 1113 Sofia, Bulgaria
2Field Crop Institute, 6200 Chirpan, Bulgaria

Abstract. Three fungal pathogens: Mycosphaerella graminicola (anamorph Zymoseptoria tritici), Phaeosphaeria nodorum (anamorph Stagonospora nodorum) and Phaeosphaeria avenaria f. sp. triticea (anamorph Stagonospora avenae f. sp. triticea) cause diseases on wheat (Triticum aestivum and Triticum durum) worldwide, known under the common name Septoria/Stagonospora diseases. In bread wheat (T. aestivum) studies have been carried out and information has been obtained on the state of the problem in Bulgaria. The purpose of the present investigation was to establish distribution and relative impact of Septoria/Stagonospora diseases and their causal agents on durum wheat (Triticum durum). The study showed that S. avenaria f. sp. triticea was the most common pathogen of this group during the studied period (2010 – 2014). Anamorph was primarily recorded. Teleomorph occurred with increasing frequency from the beginning of ripening. Z. tritici was not found in the first three years of the study. In 2013 six samples only were associated with Z. tritici infection. However, a large-scale occurrence of this fungus was established under extremely favorable weather conditions in 2014. S. nodorum was not recorded so far on the durum wheat cultivars included in the study. A comparative description of the symptoms caused by S. avenae f. sp. triticea and Z. tritici on the leaves of durum and bread wheat was made.