Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Plant Pathology


Stem rust, Puccina graminis tritici Eriks. And Henn., and leaf rust, Puccinia recondite Rob. Ex Desm., have been major diseases of wheat in the northern great plains for many years. As a result of several severe wheat rust epidemics within the past 50 years, much effort has been directed toward control of these diseases. Resistant varieties have been introduced over the years, but wheat rusts remain serious problems, causing losses to farmers in spite of breeding efforts. Since the discovery that both stem and leaf rust exist in several biological forms called races (18, 25), wheat breeding has been develop resistance toward the prevalent races in a given area. Because new races develop from natural sources, and non-prevalent races may become prevalent, breeding for resistance to specific races is a continuous struggle. As long as this situation exists, there will be no end to the breeding for resistant varieties. If resistance could be found that would be uniform in its effect on all races of rust, this might provide an answer to the problem. Several investigators have suggested that a uniform type of resistance exists. J.E. Van der Plank has proposed the name “horizontal resistance” for this and is the leading proponent of its existence. If Van der Plank is correct, and this form of resistance does exist in wheat, its use could revolutionize wheat breeding. This study has been conducted to determine if horizontal resistance to leaf rust can be detected in spring wheat.

Library of Congress Subject Headings

Leaf rust of wheat.
Plant diseases.



Number of Pages



South Dakota State University