Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2005
Publication Date: January 20, 2006
Citation: Haynes, K.G., Christ, B.J., Zink, R.T., Davidson, R.D., Miller, J.S. 2006. Powdery scab trials of potato varieties and advanced selections in 2003. [abstract]. Amer. J. Potato Res. 83:113.
Powdery scab, caused by 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. Nineteen potato clones were evaluated in replicated field plots in Pennsylvania, Colorado, and Idaho in 2003. At harvest, the proportion of powdery scab infected tubers was recorded. The square root of percent scabby tubers 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 ID (9%), and similar in CO (39%) and PA (32%). There were significant differences among clones at each location. There were significant differences among clones and the clone x environment interaction was significant for data combined from PA and ID. The CO data could not be added to the data set and meet the assumptions of normality. The genetic, genotype x environment and environmental variance components accounted for 71.2%, 22.3% and 6.5%, respectively, of the total phenotypic variance when data were combined over two locations (PA and ID). A93157-6LS, B0766-3, MSG227-2, Ranger Russet, Russet Burbank, and W1836-1rus had the lowest incidence of powdery scab; AF1921-4, B0766-3, ND2470-27, and W1201 had the highest incidence. 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.