Selection of resistant lines is the major approach followed for its control at the International Center for Agricultural Research in the Dry Areas (Icarda), however there are races believed to bu multiple races of the pathogen (Vir and Grewal,1974). This study reports on existing pathogenic variability in A. rabiei in Syria and Labanon.

Fifty Chickpea samples affected by blight were collected from Sryia and the Beqa'a Valley of Lebanon during the 1981-82 season from winter and spring sown crops. Sampling sites included farmers' fields, experiment stations and Icarda's off-station and on farm trials sites.

Pieces of diseased stems, leaves, pods, and seeds surface sterilized in 0.1% mercuric chloride for 2 minutes were plated on chickpea seed meal-dextrose agar (CSMDA). Single spore isolations of the cultures were obtained and maintained on slants of CSMDA. Cultural and morphological characters of the isolates were studied on CSMDA plates incubated at 20o C under continuous light. To measure growth rate, 5 mm discs from the peripheries of 10 day old cultures were transferred to CSMDA plates and colony dia meter measured at weekly intervals for three weeks. One hundred pycnidia and pycnidiospores were measured for each isolated. Total spores in 0.1 mm3 suspension were counted and the number multiplied by 10,000 to obtain number of spores/ml. Each count w as an average of two samples.

Each set of cultivars was grown in an iron tray of 40x30x7 cm filled with unsterilized field soil-sand mixture (3:1). Seeds were treated with Calixin M (11% tridemorth + 36% maneb) at 3g/kg of seeds. Fifteen day old seedlings were inoculated by spraying until run-off with spore suspension from 10-day old cultures propagated on CSMDA. After inoculation, seedlings were kept in a plastic house at 15-20o C and covered with polythene cages 40x30x30 cm for 5 days.

Blight severity was recorded 30 days after inoculation. Lines with stem lesions up to 6 mm long, with or without girdling, with no or a few pycnidia, and up to 15% breakage of branches were classified as resistant. Those with more than 40% breakage of b ranches, to complete killing with a large number of pycnidia were classified as susceptible. Lines with intermediate reaction were considered tolerant.

Based on there character, the fifty isolates were divided into 24 groups. Groups 1,2, and 23 were isolates from the blight-screening nursery at Tel Hadya, ICARDA, and groups 3, 21, and 24 were isolates from resistant cultivar ILC 482 in on-farm trials. Groups 4 to 15 came from experimental stations and Icarda's off station sites, and 16 to 20 from local cultivars grown in farmers' fields. Group 18 was the slowest growing and least sporulating. Group 15 had the largest pycnidial size (252.6x219.0 um) a nd group 20 the smallest (146.1x139.2 um). Croup 24 showed strandy growth in culture.

All except group 4 were pathogenic and showed large variation in virulence. Based on disease reaction of six differentials, the 24 groups were classified into six races.