Breeding Kabuli Chickpeas for Ascochyta Blight Resistance.

Ascochyta blight (AB) caused by Ascochyta rabiei is one of the devastating diseases of chickpea in different chickpea growing areas in the world. Occasionally in epidemic form it causes heavy yield losses, sometimes leading to complete crop failures. Although various chemical and cultural practices have been identified to combat the disease, their usage has been reported as uneconomical with the presently cultivated varieties having low level of resistance. Thus host resistance seems to be the only alternative. The Ascochyta rabiei pathosystem being sexual in nature seems to be very complex. Existing variability in the ascochyta pathogen has been characterized into three pathotypes, designated as I, II, and III. Pathotype I and II are reported from most of the places whereas pathotype III that is more virulent is not widely disturbed. In addition, a new virulent to all sources of resistance has been confirmed and pre-emptive breeding will be initiated. Microsatellites (SSR) profile has been developed to characterize the pathogenic variability in these pathotypes while identification of molecular markers linked to host gene(s) and their utilization in selection is in progress. The breeding program at ICARDA is achieving good success in pyramiding the genes for resistance to ascochyta blight and has resulted in improved chickpea germplasm with relatively sustainable or horizontal resistance. The newly developed elite lines developed through breeding efforts at ICARDA have been evaluated for resistance to ascochyta blight and sources of resistance identified for sharing with NARS. There is a need to explore the wild Cicer species to introgress the resistance genes to the cultigen through innovative techniques. Key words: Ascochyta blight, chickpea, breeding, pathotypes, gene pyramiding