Randhawa, H., Puchalski, B. J., Frick, M., Goyal, A., Despins, T., Graf, R. J., Laroche, A. and Gaudet, D. A. 2012. Stripe rust resistance among western Canadian spring wheat and triticale varieties. Can. J. Plant Sci. 92: 713–722. Stripe rust (Puccinia striiformis Westend.) is an important pathogen of wheat in western Canada and worldwide. One hundred and four spring wheat and triticale varieties and cultivars were evaluated for resistance to stripe rust in nurseries at Lethbridge and Creston, BC, during 2009 and 2010. In the Canada Prairie Spring Red (CPSR) wheat class, newer varieties were more resistant compared with many of the older varieties. Among the white Canada Prairie Spring White (CPSW) wheats, Vista was moderately resistant, whereas Snowhite475 and Snowhite476 were susceptible. Little useful resistance was observed within the Canada Western Hard White Spring (CWHWS) class. Sixty percent of the Canada Western Red Spring (CWRS) wheats, including the currently popular varieties Lillian, Harvest and Kane, were resistant. Susceptible CWRS varieties that are extensively seeded in western Canada include AC Barrie, Superb and McKenzie, but also include the recently registered CDC Kernen and Vesper. The varieties were tested for the presence of the stripe rust genes Yr10, Yr17, Yr18 and Yr36 using molecular markers. Much of the stripe rust resistance, particularly in the CWRS, Canada Western Extra Strong (CWES), and CPSR wheat classes was attributed to the presence of adult plant resistance gene Yr18. Yr17 and Yr36 were also detected among CWRS and CWES varieties. However, the absence of markers for known genes in several resistant varieties indicated that uncharacterized genes for stripe rust occur among hexaploid wheats. Durum wheat and triticale varieties were universally resistant with the absence of tested markers. Therefore, there appear to be numerous sources of stripe rust resistance, both characterized and uncharacterized, among western Canadian spring wheat and triticale varieties.