POTATO GENETICS, CYTOGENETICS, DISEASE RESISTANCE, AND PRE-BREEDING UTILIZING WILD AND CULTIVATED SPECIES
Location: Vegetable Crops Research Unit
Title: The potential for early generation selection to identify potato clones with resistance to Verticillium wilt.
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 26, 2008
Publication Date: April 4, 2008
Citation: Bae, J., Jansky, S.H., Rouse, D.I. 2008. The potential for early generation selection to identify potato clones with resistance to Verticillium wilt.. Euphytica. 164(2):385-393.
Interpretive Summary: Verticillium wilt is a serious disease of potatoes. Breeders are interested in developing clones with resistance to Verticillium wilt. Effective selection early in a breeding program would allow breeders to more rapidly develop resistant cultivars. This study showed that selection against the most susceptible clones, based on low yield in infested fields, is the best strategy to improve Verticillium wilt resistance in potato breeding populations.
Verticillium wilt (VW) of potato, caused primarily by the fungus Verticillium dahliae, results in yield loss and is therefore an important soil-borne disease. Resistance to VW exists in potato germplasm and is used by breeders during cultivar development. Breeders could make more rapid progress toward the development of VW resistant clones if they had an effective early generation selection strategy. The purpose of this study was to determine whether selection for VW resistance could be carried out in the first tuber generation on single hills. One hundred and fifty two clones from 19 families were planted as single hills on a V. dahliae-infested field. Each plant was scored for vine maturity, VW symptom expression, yield, stem colonization (colony forming units, cfu, in dried basal stem segments) and incidence (percent infected stems). Clones were tentatively classified as resistant, intermediate, and susceptible based on stem colonization scores and incidence in the second clonal generation, which consisted of replicated four-hill plots. The efficiency and reliability of the single-hill selection strategy, based on symptoms and yield, was then determined by comparison to the four-hill results. We determined that the best single-hill selection strategy was negative selection (discard clones with the lowest performance) with low stringency, based on yield.