Associate Plant Pathologist, The Connecticut Agricultural Experiment Station, New Haven 06405
Cooperative Research Centre for Legumes in Mediterranean Agriculture, The University of Western Australia, Nedlands WA 6907 Australia
Agriculture Western Australia, Locked Bag No. 4, Bentley Delivery Centre, WA 6983 Australia
Twenty-six isolates of Colletotrichum gloeosporioides were isolated from diseased ornamental lupines (Lupinus spp. ‘Russell Hybrids’) in seven different nurseries in Connecticut from 1996 to 1998. Three isolates from New Hampshire, New York, and Utah were also included. All isolates identified were pathogenic on lupine and vegetatively compatible with each other. Representative isolates were compared to lupine isolates from Quebec, Canada and France (COL-1 group), and from Australia and France (COL-2 group). Both groups are responsible for causing anthracnose of ornamental and forage Lupinus spp. in these countries. The Connecticut isolates were vegetatively compatible with the isolates in the COL-2 group and had random amplified polymorphic DNA profiles consistent with isolates in the COL-2 group. Isolates in the COL-1 group were vegetatively compatible only with each other and had random amplified polymorphic DNA profiles that differed from the COL-2 group. Isolates in both COL-1 and COL-2 were sensitive to both benomyl and thiobendazole, but the COL-1 group could be distinguished as slightly more tolerant than the COL-2 group and the Connecticut isolates. These assays provided persuasive evidence that the isolates from Connecticut belong to COL-2 group. The introduction of this homogenous pathogen population in Connecticut is likely due to the importation of infested seeds.