Response of Vicia species to ascochyta fabae and Uromyces viciae-fabae

Abstract

A collection of 267 accessions belonging to 61 Vicia species other than V. fab a was screened under growth chamber conditions for response to Ascochyta fabae and Uromyces viciae-fabae, causal agents of ascochyta blight and faba bean rust, respectively. High resistance to both diseases was very frequently detected in Vicia spp. in contrast to the high susceptibility previously reported in most V. f a b a accessions. Most of the Vicia spp. accessions studied here were very resistant or even immune to A. fabae with only one per cent of the accessions allowing development of small lesions bearing pycnidia. High resistance or immunity to U. viciae-fabae was also frequently found in the collection, with only ten per cent of the accessions showing compatible interaction although with reduced disease severity. These findings reinforce the specificity of A. fabae and U. viciae-fabae and clarify the potential role of cultivated and wild Vicia spp. in the epidemiology of these faba bean diseases.