ARS | Publication request: Verticillium wilt resistance in U.S. potato breeding programs

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: April 12, 2008
Publication Date: July 26, 2008
Citation: Jansky, S.H. 2008. Verticillium wilt resistance in U.S. potato breeding programs [abstract]. American Phytopathological Society. 98:S74.

Technical Abstract: Verticillium wilt is a serious disease that causes annual yield loss in most potato production regions in North America. It is most commonly caused by the soil-borne fungal pathogen Verticillium dahliae. The only consistently effective control practice is fumigation. Therefore, host plant resistance offers an attractive alternative control method. High levels of resistance are not present in most commercially significant cultivars, although ‘Ranger Russet’ is considered to be resistant. In a two year study, 11 cultivars and 14 advanced breeding clones from throughout the U.S. were evaluated for resistance to V. dahliae. They were planted into infested soil and evaluated for symptom expression (AUDPC), fresh stem colonization (colony forming units per ml plant sap) and dried stem colonization (cfu per g dry stem). Significant differences were detected for clone, year, and the clone by year interaction. Dried stem counts were higher in 2006 than in 2007, while sap counts were higher in 2007 than in 2006. The most resistant clones in both years included the cultivar ‘Megachip” and four clones from three potato breeding programs. This study indicates that good progress is being made toward the incorporation of Verticillium wilt resistance into potato breeding programs in the U.S.