W. Ralph Singleton, 82, a professor emeritus of the University of Virginia who was an authority on genetics and plant breeding with the use of radiation, died of arteriosclerosis July 28 in a nursing home in Charlottesville, Va. He lived in Charlottesville.

Dr. Singleton went to the University of Virginia in 1955 as director of the old Blandy Experimental Farm, which was jointly run by the university and the old Atomic Energy Commission, in Boyce, Va. Experiments on the farm centered on the breeding of sweet corn through the use of radioactive cobalt. Dr. Singleton retired as the farm's director in 1965 but continued to teach at the university until retiring in 1970.

His work in genetics involved research on the development of a blight-resistant chestnut tree.

He was a past president of the American Genetic Association and had been vice president and secretary-treasurer of the Genetic Society of America. He also had been an adviser on radiation genetics to the governments of the Philippines and Thailand.

He was named "Father of Sweet Corn Breeding" in 1976 by the National Sweet Corn Breeders Association.

Dr. Singleton was a native of Jacksonville, Mo. He earned bachelor's and master's degrees at Washington State University and another master's degree and a doctorate in botany at Harvard University.

He worked at the state agricultural station in New Haven, Conn., from 1927 to 1948. Before moving to Virginia, he was senior geneticist at Brookhaven National Laboratories on Long Island where he directed experiments on the growth patterns of flowers and vegetables through radioactive cobalt.

Survivors include his wife, Dorothy A., of Charlottesville; two sons, Thomas A., of Simsbury, Conn., and Willard R. Jr., of Charlottesville; two daughters, Mary Tabor of Columbus, Ohio, and Margaret Donarek of Washington; a brother, Harry, and a sister, Fern Whyte, both of Longview, Wash., and nine grandchildren.