Fazal Rahman

Document Type

Dissertation - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)

Department / School

Plant Pathology

First Advisor

James G. Ross

Second Advisor

Wayne S. Gardner


Thirty-five winter and fourteen spring wheat varieties were evaluated for their reaction to wheat streak mosaic virus during 1969-1970 and 1970-1971. Plants were mechanically inoculated and the effects of virus were measured, relative to the control plots, in regards to seed yield, protein percentage, plant height, test weight, 1000-seed weight, number of tillers per plant, number of heads per tiller, number of seeds per head, and number of plants in the 2-foot subplot. Varieties were compared visually for their susceptibility to the virus in terms of percentage infection and severity of symptoms. Seed yield, plant height, test weight, 1000-seed weight, and number of seeds per head were drastically reduced by the virus while protein percentage increased in the diseased plots. In a few cases number of tillers per plant, number of heads per tiller, and number of plants were also influenced slightly. Spring wheat varieties, Chris, Bonanza, and Fortuna and winter wheat varieties Scout, Trader, 8D6716, SD6749, SD66171, OK6955033, Lancer, NB68508, SD6753, SD6742-l, and Scout 66 were found to possess desirable degrees of tolerance to the wheat streak mosaic virus. It is concluded that the tolerance of these varieties as indicated by minimum yield reduction resulting from infection as well as basic yielding potential can make their use of considerable economic advantage in areas where the disease is pandemic and also this tolerance can be useful in a breeding program.

Library of Congress Subject Headings

Wheat -- Disease and pest resistance
Wheat streak mosaic virus



Number of Pages



South Dakota State University