Submitted to: Annual National Potato Council Seed Seminar
Publication Type: Proceedings
Publication Acceptance Date: 10/13/2000
Publication Date: 11/30/2000
Citation: BROWN, C.R. SELECTION OF PARENTS FOR VIRUS RESISTANCE IN A POTATO BREEDING PROGRAM. PROCEEDINGS OF THE 19TH NATIONAL POTATO COUNCIL SEED SEMINAR, NOV 30-DEC 2, 2000, LAS VEGAS, NV. P 21-29. 2000.
Interpretive Summary: Virus diseases of potato are currently a major cost of production. In the Pacific Northwest, $ 100 million dollars are expended annually on virus control, including the surcharges on seed potatoes, insecticides used to control aphid vectors, and fumigants used to control nematode vectors. The viruses potato leafroll virus (PLRV) and potato virus Y (PVY) are currently ythe most damaging viruses. PLRV is vectored by aphids. It is controlled somewhat effectively by insecticide applications. The most serious economic consequence is net necrosis in the Russet Burbank cultivar. PVY, also aphid vectored, is not easily controlled by insecticides. Recently, PVY has become a more serious problem because of the predominance of two cultivars that harbor PVY symptomlessly. This has meant that there wide distribution and availability of PVY inoculum, and lack of ability to remove it from seed supplies by the least expensive measures, such as roguing. Tobacco rattle virus (TRV) is transmitted by the stubby root nematode into the tuber which develops a necrotic reaction called corky ringspot disease. Corky ringspot disease has increased in severity and frequency in recent years. Corky ringspot disease is controlled by soil fumigation. The provision of healthy seed, and effective pesticidal management practices are the most immediate solution to these problems. Both wild species and cultivated potatoes have provided genetic factors for resistance. Breeding efforts on the part of the USDA/ARS in the Pacific Northwest have assembled materials that are resistant to all of these viruses. In the end, new virus resistant varieties provide the best solution to these pathogens in reducing cost of production, losses of quality, and the need for pesticides and soil fumigants.
Technical Abstract: Among the many traits that a potato breeder must select in a breeding program is resistance to virus. Resistance to virus is not always high on the priority list because virus infection is considered to be a problem that may be effectively dealt with by seed programs. Indeed it often appears that problems with viruses occur in cycles. A build-up in the incidence of a particular virus is addressed by a corresponding vigilance, elimination of infected stock, and increased investment in detection within the infrastructure of the seed program. The availability of in vitro seed stock provides the opportunity to start over with virus free material.