PATHOGENIC DIVERSITY IN Ascochyta rabiei IN CHICKPEA (Cicer arietinum L.) IN THE WESTERN OF ALGERIA

Ascochyta rabiei is a fungus agent responsible for the anthracnose of the chickpea (Cicer arietinum L.) causing serious disease in Algeria and all over the world. Ten isolates of A. rabiei were harvested in five regions in western Algeria. Isolates used in this study are characterised pathogenically after their inoculations on thirteen chickpea lines including seven introduced lines, and six local lines. The artificial inoculations were carried out by spraying an inoculum (5.105 spores /ml) on fifteen (15) days aged seedlings. The results obtained show the existence of a pathogenic variability of this agent. Regarding the evaluation of the aggressiveness of the studied isolates, it seems that the isolate MSC2 is particularly aggressive with respect to all inoculated lines, followed by SB2 and REL1, five isolates are moderately aggressive (MSC1, SB1, SB3, MOS2 and REL2), two are non -aggressive isolates (AT1 and MOS1). The aggressivity study revealed three levels of aggressiveness: highly aggressive isolates, moderately aggressive isolates and non-aggressive isolates. For the evaluation of the reaction of tested chickpea lines, the results obtained allowed us to classify the tested lines in three categories. Through this study, we believe that pathogenic variability is necessary for an approach to molecular characterisation.