Reaction of genotypes from several species of grain and forage legumes to infection with a French pea isolate of the oomycete Aphanomyces euteiches
Résumé
The susceptibility/resistance to Aphanomyces euteiches of various genotypes (cultivars and breeding lines) of several grain legume species was assessed in controlled conditions. A total of 279 genotypes from the major grain legumes grown in temperate climates (faba bean, chickpea, lentil, lupin and common vetch) and three other legumes frequently cultivated in France (French bean, clover and alfalfa) were screened with one pea-infecting isolate from France. Four different categories of susceptibility/resistance were identified among the legume species/cultivars tested with the pea A. euteiches isolate: (1) susceptible legume species (lentil, alfalfa, French bean) among which low levels of partial resistance was observed; (2) legume species including susceptible genotypes and genotypes with high levels of resistance (common vetch, faba bean and clover), (3) species with a very high level of resistance (chickpea) and (4) species displaying no symptoms (lupin). It is therefore important to consider pathogen-species and pathogen-genotype interactions when defining the host specificity of A. euteiches and considering the possible role of different legume species in increasing or decreasing the soil inoculum potential.