Resistance in Vicia faba Germ Plasm to Blight Caused by Ascochyta fabae. S. B. Hanounik, Plant Pathologist, Food Legume Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), P.O. Box 5466, Aleppo, Syria. L. D. Robertson, Plant Breeder, Food Legume Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), P.O. Box 5466, Aleppo, Syria. Plant Dis. 73:202-205. Accepted for publication 24 August 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0202.

Of the 672 germ plasm lines evaluated in 1980 and 1981 for resistance to Ascochyta fabae in Syria, 19 were resistant and 653 were susceptible. Resistant lines were tested again in Syria, England, Canada, Poland, France, and Tunisia in 1983, 1984, and 1985. Lines BPL 471, 460, 646, 74, and 2485 were resistant at all locations, whereas lines BPL 472, 818, and ILB 1814 were resistant at some, but not all, locations. BPL 471 and 2485 revealed no differential host-pathogen interactions, whereas BPL 818 and ILB 1814 consistently showed significant differential interactions when inoculated with eight isolates of the pathogen from Syria. Therefore, BPL 471 and 2485 seemed to carry genes for a broad-based general resistance compared with those for a narrow-based specific resistance of BPL 818 and ILB 1814. Based on their interactions on BPL 818 and ILB 1814, the eight isolates of A. fabae were classified into four groups representing races 1, 2, 3, and 4.