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United States Department of Agriculture

Agricultural Research Service

Title: Genetics and Breeding of Virus Reseistance: Traditional Methods

Authors
item Brown, Charles
item Corsini, Dennis

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: February 15, 2001
Publication Date: September 22, 2001
Citation: BROWN, C.R., CORSINI, D.L. GENETICS AND BREEDING OF VIRUS RESEISTANCE: TRADITIONAL METHODS. IN:VIRUSES AND VIRUS-LIKE DISEASE OF POTATO. KLUWER PRESS, EDS. LOEBENSTEIN, LAWSON, BERGER. CH 13.1:323-340. 2001.

Interpretive Summary: Viruses of potato are a major production constraint. Generally seed programs are designed to produce virus-free seed stock and certified seed of potato harbors a very low incidence of virus. In the Northwest 100 million dollars are spent annually to control virus. Extensive breeding in Europe has lead to the release of numerous varieties with resistances to PVX, PVY, PVA. However, none of these varieties has had commercial success or widespread acceptance. It is more difficult to achieve high levels of resistance to Potato leafroll virus (PLRV). The most common form of resistance to PLRV is partial field resistance. Genotypes with this type of resistance can either present a low incidence of infection, maintain virus at a very low concentration in the plant, or retard movement of virus from the foliage to the tubers. Combinations of these mechanisms are also possible. There is only a modest level of PLRV available in certain cultivars, but none of the top varieties are even moderately resistant. Another virus of importance is the tobacco rattle virus which is transmitted to the potato by the stubby root nematode, producing the tuber necrosis called corky ringspot. Very high levels of resistance have been identified and are being incorporated into new varieties. Virus resistance has often been considered of secondary importance in breeding programs. It is important to give it high priority as a means of reducing pesticide use in potato production and reducing the contamination of the environment from agricultural sources.

Technical Abstract: Viruses of potato are a major production constraint. Generally seed programs are designed to produce virus-free seed stock and certified seed of potato harbors a very low incidence of virus. In the Northwest 100 million dollars are spent annually to control virus. However, wild species and primitive cultivars provide sources of high levels of resistance. Resistance to potato viruses Y, A, X, M, and S derived from various germplasm sources are available as single dominant genes. Single gene resistances for PVY and PVA were extracted from Solanum stoloniferum and Solanum tuberosum ssp andigena. Single gene resistance to PVX was extracted from Solanum acaule, and Solanum tuberosum ssp andigena. Single gene resistance to PVS expressed as hypersensitivity was extracted from S. tuberosum ssp andigena. Immunity to PLRV has been detected in Solanum chacoense. Although there is single gene source of hypersensitivity to PLRV, it has not been widely used. The plants with thi type of resistance die when infected, making the risk of total crop failure a possibility. The most common form of resistance to PLRV is partial field resistance. The genetic control is polygenic in nature producing small percentages of highly resistant breeding clones. Tobacco rattle virus is transmitted to the potato by the stubby root nematode, producing the tuber necrosis called corky ringspot. Very high levels of resistance have been identified and are being incorporated into new varieties. Virus resistance has often been considered of secondary importance in breeding programs. New trends in virus epidemiology and the desire to reduce the use of insecticides and fumigants to control them have elevated virus resistance to a high priority status.

Last Modified: 11/20/2014
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