Changes in foliar host reaction to ascochyta rabiei with plant maturity

Ascochyta rabiei is the most significant foliar disease of chickpea (Cicer arietinum) worldwide, and can cause both yield loss and reduced seed quality. Significant mean disease score differences were observed from the reactions among a collection of Ascochyta rabiei isolates and chickpea hosts at both seedling and maturity growth stages (P<0.000). Although isolates ranked similarly within their range of pathogenicity at either growth stage, the ranking of host disease reaction was different. This suggests that genotype-specific expression of resistance genes to A. rabiei may be related to growth stage. Hence, durable selection methods for resistance will require screening of isolates representative of the pathogenicity within the population on target genotypes at growth stages representative of the type of resistance being sought, for example seedling resistance or pod resistance.