Woody Landscape Plant Breeding in Minnesota (45° N): It's not all about Cold Hardiness

The Woody Landscape Plant Breeding project at the University of Minnesota has been in existence since 1954. The project was initiated largely to develop an extended palette of cold-hardy woody landscape plants for northern landscapes. Since its inception, it has been responsible for the release of 49 woody plant cultivars including large stature shade trees, small stature flowering trees, shrubs, roses, and deciduous azaleas. Given the project's success at building a cold-hardy germplasm pool for a number of woody taxa, recent breeding efforts have been directed towards other traits such as disease resistance in several plant taxa. Projects include an examination of the nature of resistance to powdery mildew disease (Microspharae spp.) in deciduous azalea (Rhododendron subg. Pentanthera (G. Don) Pojark) species and cultivars in both field and growth chamber studies; a physiological race and an Amplified Fragment Length Polymorphism (AFLP) molecular characterization of the rose black spot pathogen (Diplocarpon rosae Wolf) and identification of resistance genes to the disease in cultivated rose (Rosa xhybrida). Recently, a high-throughput screening protocol to facilitate the identification of resistance to golden canker disease incited by the fungal pathogen (Cryptodiaporthe corni (Wehm.) Petrak) in a tree native to the upper midwestern U. S., Pagoda dogwood (Cornus alternifolia L.) has been initiated.