Résumé:
The ascochyta blight fungus Ascochyta rabiei (Pass.) Lab. is considered the most damaging
pathogen of chickpea (Cicer arietinum L.). Sixteen isolates of the pathogen were collected from six regions in
north-western Algeria and were studied for cultural diversity, morphology, pathogenicity and mating type.
These isolates showed variation in colony colour as mouse gray, light green, olive green, brown and dark
brown, when grown on chickpea seed meal dextrose agar. The produced Conidia had a length ranging from 5.2
to 17.2 μm and a width between 2.4 and 6.7μm. Their number varied from 0.13 x 107/ml to 2.52 x 107/ml. The
aggressiveness of isolates was evaluated on 11 chickpea lines. Disease rating on a 1-9 scale indicated a large
variability among them and revealed occurrence of the highly aggressive pathotype III in two regions. Both
mating types 1-1 and 1-2 were detected. Results from this study show that local strains may overcome
resistance in commonly used chickpea cultivars. Some of the described isolates will be useful for breeding
Ascochyta blight-resistant chickpea cultivars adapted to geographical regions and for developing necessary
control measures.
