Circumscription of the anthracnose pathogens Colletotrichum lindemuthianum and C. nigrum

The anthracnose pathogen of common bean (Phaseolus vulgaris) is usually identified as Colletotrichum lindemuthianum, while anthracnose of potato (Solanum tuberosum), peppers (Capsicum annuum), tomato (S. lycopersicum) and several other crop plants is often attributed to C. coccodes. In order to study the phylogenetic relationships of these important pathogens, we conducted a multigene analysis (ITS, ACT, TUB2, CHS-1, GAPDH) of strains previously identified as C. lindemuthianum, C. coccodes and other related species, as well as representative species of the major Colletotrichum species complexes. Strains of C. lindemuthianum belonged to a single clade; we selected an authentic specimen as lectotype, and an appropriate specimen and culture from the CBS collection to serve as epitype. Two clades were resolved within C. coccodes s. lat. One clade included the ex-neotype strain of C. coccodes on Solanum, while an epitype was selected for C. nigrum, which represents the oldest name of the second clade, which occurs on Capsicum, Solanum, as well as several other host plants. Furthermore, we recognized C. lycopersici as a synonym of C. nigrum, and C. biologicum as a synonym of C. coccodes.