Response of vetches (Vicia spp.) to specialized forms of Uromyces vicia-fabae and to Uromyces pisi

Abstract

The genus Vicia includes many species of agricultural interest, such as faba bean and the various vetches that may be infected by rust, with little understanding of the specificity of these interactions. This work contributes to the clarification of host range of Uromyces viciae-fabae and Uromyces pisi, and confirms host specialization within U. viciae-fabae. The differential response of Vicia faba, Vicia sativa and Lens culinaris checks confirms the existence of specialized isolates of U. viciae-fabae. Host range of these host specialized forms of U. viciae-fabae was not so clear cut when we test other species of Vicia. The most specialized form was U. viciae-fabae ex V. faba that was able to infect profusely only faba bean (V. faba), all other Vicia species being highly resistant. Conversely, susceptibility against U. viciae-fabae ex V. sativa was very common in Vicia spp., particularly in those belonging to the subgenus Vicia, although not in V. faba. Still, susceptibility could be identified in a number of accessions of section Cracca such as Vicia cracca, Vicia monantha, Vicia sicula or Vicia villosa. Most Vicia accessions were highly resistant to U. viciae-fabae ex L. culinaris, but a number of accessions could be severely rusted, particularly in species of the subgenus Vicilla but also in some of section Peregrinae of subgenus Vicia. Similarly, most Vicia accessions were highly resistant to U. pisi but a number of accessions could be severely rusted, particularly in species of the subgenus Vicilla and in sections Hypechusa and Peregrinae of subgenus Vicia. This work also identified sources of resistance to the various rusts that can be used in rust resistance breeding. In spite of the susceptibility against various rusts, interesting levels of resistance were identified in crops and related species being based either on hypersensitive response or on reduced severity in spite of a compatible interaction making resistance breeding feasible. © 2012 Elsevier Ltd.