Study on virulence variability in Ascochyta rabiei isolates in Iran

Ascochyta blight caused by Ascochyta rabiei (Pass.) Lab. is the most damaging disease of chickpea worldwide. A sever epidemic of disease can totally destroy the crop. Finding resistant or tolerant cultivars is the best way of controlling this disease. In the present study, pathogenic diversity in A. rabiei was determined using 30 isolates collected from chickpea fields in East-Azarbayjan, Ilam, Kermanshah, Lorestan and Kohgiluyeh-Boyerahmad Provinces of Iran. The interactions between isolates of the fungus with seven differential chickpea lines (ILC-202, ILC-1929, ILC-194, ILC- 5928, ILC-72, ICC-3996 and PCH-15) were studied to evaluate their virulence. A 9 point disease rating scale was used for greenhouse observations. In this study, virulence of 30 isolates of A. rabiei was determined and the isolates fell into 16 distinct groups when they were subjected to virulence assessment. The results indicated that a high level of virulence variability exists among A. rabiei isolates in Iran that should be taken into account for future breeding programs. In this regard, the line (ILC-72) was moderately resistant. This genotype is additional sources of resistance to be used in hybridization program to develop chickpea resistant cultivars. It would be desirable to use cultivars carrying non-race specific resistance gene to A. rabiei.