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ARS Home » Research » Publications at this Location » Publication #120289
Title: LATE BLIGHT IN THE UNITED STATES AND CANADA

Author
item Deahl, Kenneth
item Jones, Richard

Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Late blight, caused by Phytophthora infestans, continues to be a serious problem throughout potato production areas of the U.S. and Canada. In order to develop more effective control strategies for late blight disease management, many scientists have attempted to characterize genetic and phenotypic variation in various populations of the fungus. Although mating type changes provided the first suggestion of major modification in P. infestans populations, variations in metalaxyl sensitivity also indicated dramatic changes. The results based on morphology, pathogenicity, ribosomal internal transcribed region 2 (ITS2) sequence, isoenzyme markers, DNA fingerprints obtained using multilocus probe RG-57 and genetic markers based on analysis of mitochondrial DNA (mtDNA) have permitted further resolution of genetic diversity in populations from different locations in the U.S. and Canada. Knowledge of this diversity helped identify potential new strategies for disease management and assisted in determining where future monitoring of the pathogen is necessary. For example, an important factor for selecting effective fungicides necessary for controlling late blight is understanding the sensitivity distribution of pathogen populations to available fungicides.