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United States Department of Agriculture

Agricultural Research Service


item Haynes, Kathleen
item Christ, Barbara
item Zink, Richard
item Davidson, Robert
item Miller, Jeff

Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2004
Publication Date: 1/20/2005
Citation: Haynes, K.G., Christ, B.J., Zink, R.T., Davidson, R.D., Miller, J.S. 2005. National powdery scab trial of potato varieties and advanced selections in 2002. Amer. J. Potato Res. 87:73 (Abstract).

Interpretive Summary:

Technical Abstract: Spongospora subterranea f sp. subterranea, is a significant disease of potato in the United States. Little is known about the reaction of U.S. potato varieties to this organism. The purpose of this study was to determine if there is any genetic resistance to powdery scab among U.S. potato germplasm. Seventeen potato clones were evaluated in replicated field plots in Pennsylvania, Colorado, and Idaho in 2002. At harvest, the proportion of powdery scab infected tubers was recorded. The arcsin transformation of the square root of proportion of scabby potatoes was analyzed to stabilize the variance. This variance stabilization was successful for PA and ID, but not for CO. The incidence of powdery scab was lowest in CO (2%), greatest in ID (45%), and intermediate in PA (9%). Under severe conditions (ID) there were no significant differences among clones. There were significant differences among clones under less severe conditions (PA and CO). There were no significant differences among clones when data were combined over the two locations with moderate to severe disease pressure or over all three locations. The genetic, genotype x environment and environmental variance components accounted for 53%, 17% and 31%, respectively, of the total phenotypic variance when data were combined over three locations, and 51%, 10%, and 39%, respectively, of the total phenotypic variance when data were combined over two locations (PA and ID). The results of this preliminary study suggest that the evaluation of germplasm for resistance will need to be conducted for more than one year to obtain reliable information. (poster, plant protection, PAA Membership 137)

Last Modified: 07/25/2017
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