Abstract

Wheat is the 2nd most important culture in the world.  Septoria leaf blotch is one of the most important wheat diseases. It is caused by Mycosphaerella graminicola (an: Zymoseptoria tritici). The aim of this study is to evaluate the presence and the importance of this disease in Algeria. A collection of 625 isolates was made through the years (2010, 2011, and 2013). Isolates were collected from the Algerian zones of cereal production. Phenotypic and genetic characterization via morphological, cultural and pathogenic analysis showed the presence of Septoria leaf blotch in 72 fields (from 122) in 20 departments (counties). In some fields the disease is highly frequent with an index of 99 according to double digit scale. Two main types of isolates were found; but the yeast-like form dominated with 94.08%. 26 isolates sampled from 25 fields were tested to evaluate isolates aggressiveness variability. Only 2 isolates from 26 inoculated were able to produce symptoms on three cereal species (triticale, durum and bread wheat).

Key words: Zymoseptoria tritici, diversity, prevalence, virulence, wheat.