Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2005
Publication Date: 1/20/2006
Citation: Haynes, K.G., Wanner, L.A., Thill, C.A., Novy, R.G., Whitworth, J.L. 2006. Common scab trials of potato varieties and advanced selections in 2003. [abstract]. Amer. J. Potato Res. 83:113. Interpretive Summary:
Technical Abstract: Common scab, caused by Streptomyces spp., is a soil-borne disease of potato tubers that seriously affects marketability of the crop. Many factors can influence the severity of scab expression: the genotype of the host, variability of Streptomyces pathogenicity, density of bacteria within the soil profile, and environmental conditions among others. The purpose of this study was to evaluate the stability of common scab expression in advanced germplasm from public potato breeding programs in different regions of the United States. Nineteen clones, consisting of four standard check varieties (Atlantic, Superior, Russet Burbank, Ranger Russet), four recently released varieties (Alturas, Bannock Russet, Harley Blackwell, Liberator), and 11 numbered selections were evaluated in ID, ME and MN. After harvest, each tuber was scored for the percent of surface area covered with lesions and the type of lesion. These scores were converted to an area index (AI) and a lesion index (LI). There were no differences among the environments for either AI or LI. There were significant differences among clones for AI and LI. There were significant clone x location interactions for AI but not LI. Liberator and ND2470-27 were unstable for AI before removal of environmental heterogeneity; ND2470-27 and NDTX4271-1R were unstable after removal of environmental heterogeneity. Broad-sense heritability for AI and LI were estimated as 0.76 and 0.90, respectively. These results indicate that the responses of some clones vary considerably over environments and evaluation at multiple environments is important for classifying disease phenotype.