Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 19, 2010
Publication Date: August 15, 2010
Citation: Halterman, D.A., Jansky, S.H., Meier, A. 2010. Verticillium Wilt in Potato: Host-Pathogen Interactions and Breeding for Resistance [abstract]. Potato Association of America Proceedings. Paper No. 92. Technical Abstract: Verticillium wilt (VW) is a widespread disease that causes consistent yield losses in many potato growing regions worldwide. In the U.S., it is mainly caused by the soil-borne fungal pathogen Verticillium dahliae. Microsclerotia can survive in the soil for many years. When they germinate and infect potato roots, they cause vascular wilting. Host plant resistance is being pursued as an alternative to fumigation, which is currently the only effective control method. Screening for VW resistance is expensive and time-consuming, requiring replicated field trials across years and locations. Resistance evaluations are typically based on a combination of symptom expression and stem colonization scores. Quantitative PCR is being developed as an alternative method to quantify fungal biomass, rather than propagule levels, in infected stems. In addition, a molecular marker has been created based on a homolog of the tomato Ve gene. This aids in the identification of resistant clones in populations containing some wild relatives of potato, but requires further refinement for broader applicability. Finally, a seedling inoculation method is being tested for its ability to identify resistant clones in early stages of a breeding program. Seedlings exposed to the filtrate of a fungal culture show VW symptoms, indicating that a fungal toxin may be involved in disease expression. This talk will cover different methods used to differentiate resistant and susceptible individuals in the field and discus the pros and cons of each method.