Key lessons from resistant tree breeding programmes in the Northern Hemisphere

Table 1 Tree-pest/pathogen systems from which case studies were selected. Not intended to be comprehensive (see http://www.fao.org/forestry/26460/en/ for further examples). Also note that several programmes may not yet have reached deployment stage

Tree species	Pest or pathogen	Programmes
American chestnut (Castanea dentata)	Chestnut blight (Cryphonectria parasitica)	The American Chestnut Foundation¹ The American Chestnut Co-operators Foundation² Connecticut Agricultural Experimentation Station³ American Chestnut Research and Restoration Project⁴
Sitka spruce (Picea sitchensis)	White pine weevil (Pissodes strobi)	British Columbia (B.C.) Ministry of Forests, Pacific Forestry Centre and B.C. universities^5,6
Several susceptible Ulmus spp.	Dutch elm disease (Ophiostoma ulmi; Ophiostoma novo-ulmi)	Willie Commelin Scholten Phytopathological Laboratorium⁷ Italian Institute of Plant Protection^7,8 US Forest Service^7,9 University of Minnesota ^7,10 Morton Arboretum ^7,11 The Great British Elm Search¹²
Several susceptible Pinus spp.	Blister rust (Cronartium ribicola)	US Forest Service^13–15 B.C. Ministry of Forests¹⁶
American beech (Fagus grandifolia)	Beech bark disease (Nectria coccinea)	USDA^{17, 18}
Butternut (Juglans cinerea)	Butternut canker disease (Sirococcus clavigignenti-juglandacearum)	USDA^19–22
Several susceptible Pinus spp.	Dothistroma needle blight (Dothistroma spp.)	CEH, Forestry Commission, Forest Research²³ CSIRO²⁴
Several susceptible Fraxinus spp.	Emerald ash borer (Agrilus planipennis)	USDA²⁵
N. American hemlock species (Tsuga spp.)	Hemlock woolly adelgid (Adelges tsugae)	USDA^26–28

Further information available at:
¹The American Chestnut Foundation (http://www.acf.org). ²The American Chestnut Co-operators Foundation (http://www.accf-online.org). ³Connecticut Agricultural Experimentation Station (www.ct.gov/caes). ⁴College of Environmental Science and Forestry (http://www.esf.edu/chestnut). ⁵King et al. (2004). ⁶Alfaro et al. (2013). ⁷Mittempergher and Santini (2004). ⁸Santini et al. (2012). ⁹Townsend et al. (2005). ¹⁰University of Minnesota (https://www.legacy.mn.gov/projects/finding-disease-resistant-elm-trees-minnesota). ¹¹Morton Arboretum (http://www.mortonarb.org/trees-plants/tree-plant-descriptions/elm-cultivars). ¹²The Conservation Foundation (https://www.conservationfoundation.co.uk/elms). ¹³Fins et al. (2001). ¹⁴McDonald et al. (2004). ¹⁵Sniezko et al. (2008). ¹⁶British Columbia Ministry of Forests (http://www2.gov.bc.ca/gov/content/industry/forestry/managing-our-forest-resources/tree-seed/forest-genetics/tree-breeding-improvement/western-white-pine). ¹⁷Koch (2010). ¹⁸Koch et al. (2012a). ¹⁹Michler et al. (2005). ²⁰Woeste et al. (2009). ²¹McKenna et al. (2011). ²²Boraks and Broders (2014). ²³Perry et al. (2016). ²⁴Ivkovic et al. (2011). ²⁵Koch et al. (2012b). ²⁶Bentz et al. (2008). ²⁷Montgomery et al. (2009). ²⁸Oten et al. (2014)

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