Submitted to: Stem Rust of Wheat from Ancient Enemy to Modern Foe
Publication Type: Book / Chapter
Publication Acceptance Date: 4/1/2001
Publication Date: 4/1/2001
Citation: KOLMER, J.A. EARLY RESEARCH ON THE GENETICS OF PUCCINIA AND STEM RUST RESISTANCE IN WHEAT IN GRAMINIS CANADA AND THE UNITED STATES. STEM RUST OF WHEAT FROM ANCIENT ENEMY TO MODERN FOE. 2001. Peterson, P. editor. St. Paul, MN:APS Press. 2001. p. 51-82.
Technical Abstract: Stem rust of wheat, caused by Puccinia graminis, was responsible for massive epidemics on wheat in the early 20th century in Canada and the United States. Scientists working in Canada and in the United States, determined that wheat stem rust was composed of many different physiologic races that differed in ability to attack wheat cultivars that had different tgenes for stem rust resistance. Rust researchers showed that wheat stem rust races in the southern plains of the United States were carried on the southerly winds to the northern plains of the U.S. and the Canadian prairie provinces; this became known as the "Puccinia pathway." Scientists working in Canada showed that P. graminis is heterothallic and that the pcynial stage of the fungus on barberry plants is where sexual recombination occurs. The inheritance of virulence in P. graminis to various wheat cultivars was also determined by scientists in Winnipeg. Stem rust resistance transferred to Marquis wheat from Kota proved to be resistant until 1935 when stem rust races with virulence to the Kota resistance became common. The cultivar Thatcher was derived by transferring stem rust resistance from Iumillo durum wheat into Marquis wheat. The Thatcher stem rust resistance was highly effective until 1950 when race15B of stem rust increased in prevalence and caused highly destructive epidemics from 1950- 1954. Stem rust resistance gene Sr6, provided resistance to race 15B, and was used in Canada to develop the stem rust resistant wheat Selkirk. Many stem rust resistant wheat cultivars have since been released in both countries and there has not been a significant stem rust epidemic on spring wheat since 1954.