Persistence of major gene resistance in western white pine (Pinus monticola) in British Columbia

Abstract

White pine blister rust, a devastating disease caused by the rust pathogen Cronartium ribicola, has been attacking and killing western white pines (Pinus monticola) for more than 100 years since its introduction to the Canadian province of British Columbia (BC) (Hunt 2009). There is a single dominant (major) gene for resistance (MGR) that produces a hypersensitive infection spot similar to that observed in resistant reactions in other plants attacked by rust pathogens. It was first found in a limited geographic area of southern Oregon, USA, known as the Champion Mines (Kinloch et al. 1999). Resistant Champion Mines clones were established at Dorena, Oregon, in the mid-1960s; since then, however, the pathogen has circumvented this resistance at Dorena and other areas in southern Oregon (Kinloch et al. 2004). This MGR resistance was imported to BC in seed collected from Dorena. Resistance came from seedlots from two geographic areas: (1) open-pollinated (OP) Champion Mines clones, and (2) OP Washington State, USA clones. Seedlings were planted into nine root disease sites in 1986 and 1987 throughout BC. Details of the plantation design using these 2 pine sources and 12 other provenances can be found in Hunt (1987) and Meagher and Hunt (1998). The first seedlot was also planted into three coastal and three interior provenance trials in 1988 (see Meagher and Hunt 1998) and the second seedlot into three demonstration plantations in 1994. These trees have been examined for growth and blister rust periodically over the years. At the previous IUFRO rust meeting held in OR in 2001, we (Hunt et al. 2004) reported that this resistance appeared to be persistent. In this report we provide a 2014 update.

Parent Publication

• Proceedings of the IUFRO joint conference: Genetics of five-needle pines, rusts of forest trees, and Strobusphere; 2014 June 15–20; Fort Collins, CO

Citation

Hunt, Richard S.; Murray, Michael; Reich, Richard; Rusch, David; Woods, Alex; Zeglen, Stefan. 2018. Persistence of major gene resistance in western white pine (Pinus monticola) in British Columbia. In: Schoettle, Anna W.; Sniezko, Richard A.; Kliejunas, John T., eds. Proceedings of the IUFRO joint conference: Genetics of five-needle pines, rusts of forest trees, and Strobusphere; 2014 June 15-20; Fort Collins, CO. Proc. RMRS-P-76. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 149-150.