| Abstract Detail
Plant Protection Aqeel, Abdullah [1], Pasche, Julie S. [1], Gudmestad, Neil C. [2]. Pathogenicity of North American Colletotrichum coccodes isolates on potato. BLACK dot, caused by Colletotrichum coccodes, is increasing in importance due to reduced tuber yield and quality. The objective of studies reported here was to determine the relationship between vegetative compatibility group (VCG) and pathogenicity of C. coccodes as well as compare foliar and root inoculation methods. Four trials were conducted under greenhouse conditions. In each trial, two plants each of three potato cultivars, Russet Burbank, Umatilla Russet, and Russet Norkotah, were inoculated with isolates classified into each of the 6 identified VCGs. Percent infection was recorded weekly beginning two weeks after inoculation, tuber weight and number were recorded 60 days after planting. A differential response was observed between foliar and root inoculation methods, as well as among all potato cultivars and VCGs in both root and foliar inoculated plants. A significant interaction existed between cultivar and VCG among foliar inoculated plants in tuber weight, but not tuber number. There was no significant interaction between cultivar and VCG among root inoculated plants, but there was a significant difference in tuber weight among the main effects of cultivar and VCG. The possible reason for this observation is that root and stolons were infected much more rapidly. A relationship existed between foliar disease severity and tuber weight reduction among all VCGs in foliar inoculated plants. Results of foliar inoculations demonstrated that VCG 1 and 6 were more aggressive than all other VCGs. However, VCG 4 and 6 were more aggressive in root inoculated plants. These results suggest there are differences among VCGs in aggressiveness to above and below potato plant organs. Potato cultivars also differed in levels of susceptibility in both above and below ground tissue.
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1 - North Dakota State University, Plant Pathology, 306 Walster Hall, P.O. Box 5012, Fargo, ND, 58105-5012, USA
2 - North Dakota State University, Plant Pathology, 310 Walster Hall, P.O. Box 5012, Fargo, ND, 58105-5012, USA
Keywords:
vegetative compatibility group
VCG
Pathogenicity.
Session: Poster-13
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:274 |
