Heirloom potato:
an underutilized source of genetic diversity
Mollov, D.1,
J. Davis2, J. Jenkins1, E. Radcliffe2, and J.
Bradeen1
1Department
of Plant Pathology
2Department
of Entomology
University of Minnesota, St. Paul, MN 55108
Heirloom
potato varieties (defined as not currently commercially prominent in the US)
are important sources of genetic diversity. Our objective is to systematically
characterize heirloom potato cultivars based on disease resistance, molecular
fingerprints, and morphology. Initiated in 2004, a number of heirloom cultivars
are planted yearly in replicated disease nurseries for screening for resistance
to foliar late blight (LB) (Phytophthora infestans), potato virus Y (PVY) and potato leafroll virus
(PLRV) at Rosemount, MN, and common scab (CS) (Streptomyces scabies) at Becker, MN. Natural or intentional inoculation provides uniform disease
pressures. To date, we have characterized 51 cultivars, each for a minimum of
two years, for resistance to LB, PVY, PLRV, and CS. An additional 32 varieties
are current targets of screening efforts. We have identified 15 cultivars as
moderately resistant to LB, one resistant to PVY, three resistant to PLRV, and
six resistant and 18 moderately resistant to CS. To understand the mechanism of
virus resistance, resistant cultivars will be screened using markers for known
PVY R genes and a QTL for PLRV
resistance. Because heirloom cultivars of the same name from different sources
may vary in genetic composition, we are generating simple sequence repeat (SSR)
marker data for all characterized cultivars. All varieties are also documented with photographs of tubers
and flowers. Our ongoing work will
provide up to date information for the selection of disease resistant materials
by researchers, farmers and home gardeners. A web-based heirloom database of
our effort can be found at http://ppg.cfans.umn.edu/. We invite other researchers with an
interest in these materials to consider collaboration on this effort.