Disease Note

Colletotrichum gloeosporioides: A New Anthracnose Pathogen of Soybean in Spain. J. García -Jiménez, Universidad Politécnica de Valencia, Valencia 46020, Spain. A. Alfaro, Universidad Politécnica de Valencia, Valencia 46020, Spain. Plant Dis. 69:1007. Accepted for publication 19 July 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-1007a.

Colletotrichum gloeosporioides (Penz.) Penz. Sacc. was observed on soybean (Glycine max (L.) Merr.) approaching maturity in Spain, where soybean is a recently introduced crop. Anthracnose caused by C. dematium (Pers. ex Fr.) Grove var. truncata (Schw.) Arx is common, but this is the first report of C. gloeosporioides on soybean in Spain. The disease has not been severe, but seed transmission has been observed. Koch’s postulates were completed with the fungus, which affected the lower stem and produced acervuli with orange cirri. Conidia were hyaline, single-celled, and bacilliform with truncated base and averaged 13.1 × 3.9 μm. Acervuli were 60–180 μm long and had few or only rudimentary setae. The host range and electrophoretic patterns were similar to those of C. gloeosporioides strains obtained from citrus groves where the fungus commonly occurs. Disease incidence was highest in the vicinity of orange groves.