|Novy, Richard - Rich|
Submitted to: American Journal of Potato Research
Publication Type: Proceedings
Publication Acceptance Date: 2/2/2009
Publication Date: 2/1/2010
Citation: Haynes, K.G., Wanner, L.A., Thill, C.A., Bradeen, J.M., Miller, J., Novy, R.G., Whitworth, J.L. 2010. Results of the 2007 National Common Scab Trials of potato varieties and advanced selections. American Journal of Potato Research. 87:126.
Technical Abstract: Incidence and severity of potato common scab (CS), caused by Streptomyces spp., vary by year and location, necessitating multiple evaluations of resistance in germplasm. In 2007, CS resistance was evaluated on 23 clones [6 varieties, 17 numbered selections] in ID, ME and MN. Clones were planted in a randomized complete block design with three replications per location. After harvest, tubers were scored for percent surface area covered with lesions and type of lesion, and scores converted to an area index (MI) and a lesion index (LI), respectively. Differences among clones were found for LI but not MI. LI for 15 clones was similar to that of Russet Burbank (moderately resistant); LI in the remaining clones was significantly more severe. Clone x location interactions were significant for both MI and LI: slightly less than half the clones were unstable before and after removal of location heterogeneity. Clones as resistant as Russet Burbank were more than twice as likely to be stable before and after removal of location heterogeneity, whereas clones more susceptible than Russet Burbank were about equally likely to be stable or unstable. These results indicate that the majority of clones evaluated expressed resistance to CS, however, none exceeded the resistance observed in the moderately resistant control, Russet Burbank. Significant clone x location interactions make germplasm evaluation in multiple locations necessary to accurately characterize response to CS and identify germplasm with stable resistance (poster, plant breeding, and genetics, PAA Membership 137.)