Chickpea varieties with resistance to ascochyta blight Screening for new genetic resource of resistance to AB Phenotyping AB resistance

Abstract

A mixture of fungal cultures of A. rabiei pathotypes (pathotypes I, II, and III) obtained from the Legume Pathology Laboratory at ICARDA was used to screen the chickpea subset. The experiment was laid out in Alpha Lattice design with two replications. A spore suspension of 105 spores mL-1 A. rabiei was prepared in sterile distilled water using a 14-day old culture grown on chickpea dextrose agar and sprayed onto plants until runoff. The disease was scored when symptoms on the susceptible check (ILC-263) was observed. Scoring was based on plants using a nine-point rating scale (Singh and Reddy 1993); where 1 = immune, no symptoms of the disease; 2 = few, very small lesions (< 2 mm) on leaves and stems (1 to 2% of the plant area infected); 3 = many small lesions (6 to 10% of the plant area infected); 4 = many small and large lesions (26 to 50% of the plant area infected); 5 = many small lesions on the stem; 6 = many large lesions, lesions coalescing, stem girdled (76 to 90% of the plant area infected); 7 = many small and large lesions, lesions coalescing, girdling stem breakage (> 90% of the plant area infected), 8 = almost dead plants; and 9 = dead plants.