In Memoriam: Dr. Theodor Otto Diener In Memoriam: Douglass W. Svendson

Dr. Theodor Otto Diener, a Swiss-American plant pathologist who was a U.S. Department of Agriculture Research Service Science Hall of Fame inductee as the discoverer of ‘viroids,’ 80 times smaller than the smallest known viruses, died last week at the age of 102 at his home in Maryland. Dr. Diener published two books, 120 peer-reviewed articles, 53 book chapters and lectured on viroids worldwide.

Diener was the father of prominent Falls Church businessman Michael Diener.

In 1971, Diener discovered that the causative agent of the potato spindle tuber disease is not a virus, but a novel agent, which consists solely of a short strand of single-stranded RNA without a protein capsid, 80 times smaller than the smallest viruses that he called “viroids.”

Dr. Diener was born in Zurich, Switzerland, on February 28, 1921 and graduated from the Swiss Federal Institute of Technology in 1946. He emigrated to the United States in 1949 and in 1959 he joined the U.S.D.A. Agricultural Research Service Center in Beltsville, Maryland, where he made his “viroids” discovery.

He was the recipient of the National Medal of Science (1987), the Campbell Award of the American Institute Biological Sciences (1968), the American Phytopathological Society fellow award (1973), the Wolf Prize in Agriculture (State of Israel, 1987) and the E.C. Stakman Award (University of Minnesota, 1987).

He was elected as a member of the U.S. National Academy of Sciences (1977), a fellow of the American Academy of Arts and Sciences (1978), the Andrew D. White Professor at Large (Cornell University, 1979), and member of the Leopoldina (German Academy of Sciences, 1980). In 1989, he was inducted into the Science Hall of Fame, Agricultural Research Service, U.S. Department of Agriculture, and was named Distinguished Professor at the University of Maryland, and in 1994 was named Distinguished Professor Emeritus there.

After receiving his doctorate from the Swiss Federal Institute of Technology, he worked as a research assistant at the Swiss Federal Experiment Station for Viticulture and Horticulture at Wadenswil, where he discovered rust fungus on the leaves of a cherry tree, the first such detected occurrence seen north of the Alps in over 100 years. Working first as Assistant Plant Pathologist at Washington State University’s Irrigation Experiment Station in Prosser, Washington, he showed that an unusual amino acid, pipecolic acid, accumulates only in peach leaves bearing symptoms of Western-X-Disease and that injection of the amino acid into healthy peach seedlings resulted in abnormalities resembling disease symptoms, thus indicating that pipecolic acid is intimately associated with the disease’s molecular pathogenesis.

At the U.S.D.A. Research Service, he discovered the causative agent of potato spindle tuber disease, for which he proposed the term, “viroid.” The discovery was subsequently officially designated by the International Committee for Virus Taxonomy as a novel order of subviral agents encompassing 2 families, 8 genera and 32 species.

In 1989, Diener hypothesized that the unique properties of viroids make them more plausible candidates as “living relics” of a hypothetical, pre-cellular RNA world than are others then considered as such. His hypothesis remains valid.

Douglass W. Svendson, Jr. passed away peacefully on Sunday, March 26, 2023, surrounded by many family members at the Baton Rouge General Hospital. Doug was a native of Baton Rouge, born in 1939.

Doug was a graduate of Notre Dame and earned his J.D. degree from LSU Law School.

In 1974, Doug relocated to the Washington, D.C. area. There he met his second wife, Dorothy “Dot” Turnipseed. He became a legislative assistant to then Senator Russell Long, and served on the staff of the Senate Commerce Committee. Doug served as an independent legislative consultant for major tank barge operators, and several motor freight associations. In 1995, Doug was named executive director of the Gulf Intracoastal Canal Association, and received the Commander’s Award for Civilian Service from the Army, and the Distinguished Public Service Award from the U.S. Coast Guard.

Doug enjoyed his big family of ten siblings, his sons, Douglass and David, and his granddaughter Maya Svendson, and grandson Matthias Junod Svendson. He loved traveling with his wife, Dot, on painting excursions. His love of hunting brought him regularly to the Eastern Shore of Chesapeake Bay, and down to South Texas for trips with close friends. He relished family gatherings at the Svendson Rice Farm in Louisiana where he could sit and partake in family traditions of cooking, and sharing stories. Doug loved to laugh, and to cook.

He is preceded in death by his parents, Douglass W. Svendson, Sr., and Jeanne Martin Svendson; his sister, Jeannette Svendson, brother Lee Svendson, his son, Douglass, and most recently by his loving wife, Dot.

Doug is survived by his first wife, Emily A. Svendson, and their sons Douglass and David Svendson, David’s wife, Sarah, their daughter, Maya; and by Douglass’ son, Matthias Junod Svendson. His surviving siblings are: Alice Svendson, Marie Svendson Pribble, Teen Svendson Siener, Kris Svendson Chadwick, Jeffery Svendson, Toni Svendson DeBosier, Martin Svendson, and Lawrence Svendson; and many nieces, nephews, great nieces and great nephews.

A small family service will be held for Doug at a later date.

Honorary pallbearers will be: David Svendson, Jeffery Svendson, Toni Svendson DeBosier, Martin Svendson, Lawrence Svendson, Matthias Junod Svendson.

In lieu of flowers, donations can be made to the American Diabetes Association, PO Box 7023, Merrifield, VA, 22116-22116-7023, or the American Heart Association, PO Box 840692, Dallas, TX 75284-0692.