Theodor Diener, scientist who found the tiny viroid, dies at 102

His son Michael Diener confirmed his loss of life however didn’t cite a trigger.

Dr. Diener immigrated to the US in 1949 and spent three a long time as a plant pathologist on the Agricultural Analysis Service, the chief inner analysis company of the U.S. Division of Agriculture.

President Ronald Reagan awarded him a Nationwide Medal of Science for his identification in 1971 of the viroid, an achievement that has been in contrast in its significance to the invention of micro organism within the late 1600s and of viruses shortly earlier than the flip of the twentieth century.

Since roughly the Nineteen Twenties, farmers had recognized of a confounding illness that threatened their potatoes, leaving them shrunken and malformed and lowering the dimensions of a crop by 50 % or extra. Within the Sixties and Seventies, according to a report in Forbes magazine, as many as half of the potato crops in some areas of China and Ukraine have been sickened.

The situation had a reputation — potato spindle tuber illness — however its trigger proved vexingly elusive.

Working for years with colleagues at ARS, Dr. Diener was credited with figuring out the infectious agent on the proverbial root of the issue. Utilizing analysis strategies together with centrifugation, he decided that the trigger was not a virus, as different scientists had speculated, however reasonably a brand new, far smaller pathogen — the viroid.

A viroid features in a fashion much like that of a virus, invading a cell and making it reproduce the viroid’s RNA. Not like a virus, a viroid has no protein coat. According to the ARSthe long-standing consensus amongst scientists was that such “bare” pathogens have been unable to copy, even with the help of an contaminated cell.

Most scientists additionally believed {that a} pathogen as minuscule because the one Dr. Diener found was incapable of invading an organism. However Dr. Diener’s analysis proved {that a} viroid — so small that it’s barely seen even with an electron microscope — can certainly mount an efficient assault.

After figuring out the viroid, Dr. Diener helped develop a check to detect the one which causes potato spindle tuber illness. Viroids have been later discovered to trigger situations together with tomato chlorotic dwarf, apple scar pores and skin, avocado sunblotch and chrysanthemum stunt. There are greater than 30 recognized species of viroids in plant pathology.

Dr. Diener’s National Medal of Scienceawarded in 1987, credited his discovery with creating “new avenues of molecular analysis into among the most critical illnesses afflicting crops, animals, and people.”

Theodor Otto Diener was born in Zurich, within the German-speaking a part of Switzerland, on Feb. 28, 1921. His father was a postal worker, and his mom was an accountant. Even in his youth, the long run scientist was drawn to crops and animals.

“As a boy, I at all times saved animals at house: turtles, salamanders, frogs, white mice, hamsters,” he as soon as advised an interviewer. “Whereas my dad and mom exhibited a big dose of tolerance to this, neighbors typically didn’t.”

His curiosity led him to ever tinier creatures, he stated, after he saved sufficient cash to purchase a secondhand Leitz microscope.

Dr. Diener studied biology on the Swiss Federal Institute of Expertise, receiving a doctoral diploma in 1948.

After immigrating to the US, the place he turned a naturalized U.S. citizen, he labored as a plant pathologist at Washington State College earlier than becoming a member of ARS in Beltsville in 1959. He collaborated on ARS analysis lengthy after his official retirement in 1988.

He additionally carried out analysis and taught on the College of Maryland, the place he was a professor emeritus.

Along with the Nationwide Medal of Science, Dr. Diener’s honors included election to the Nationwide Academy of Sciences in 1977 and the American Academy of Arts and Sciences in 1978. In 1987, he obtained the Wolf Prize in agriculture, a $100,000 award given by the Wolf Basis in Israel.

Along with his prolific scientific papers, he wrote two books, “Viroids and Viroid Illnesses” (1979) and a memoir, “Of People, Humanoids and Viroids” (2014).

Dr. Diener’s marriage to Shirley Baumann resulted in divorce. His spouse of 44 years, the previous Sybil Fox, died in 2012.

Survivors embrace three sons from his first marriage, Theodore Diener of Los Angeles, Robert Diener of Urbana, Ailing., and Michael Diener of Vienna, Va.; 5 grandchildren; and three great-grandchildren.

Like many scientific advances, Dr. Diener’s discovery of the viroid was the profitable results of many earlier unsuccessful tries. Reflecting on his efforts to decode potato spindle tuber illness, he wryly told the New York Times“we went up the backyard path many occasions.”