1a.Objectives (from AD-416)
Acquire new germplasm for breeding trees suitable for utility-line applications. Test crossability between new germplasm to determine breeding potentials and advance breeding goals.
1b.Approach (from AD-416)
New germplasm will be acquired from various botanical institutes and commercial nurseries. Wild-collections will be coordinated with the Woody Landscape Plant Crop Germplasm Repository. Material will be planted out for long-term evaluations and for conducting crosses. Controlled pollinations will be combined with molecular tools to verify hybrids and analyze diversity.
Breeding lines developed in previous research cycles, including Aesculus, Catalpa, Chitalpa, Chionanthus, Halesia, Pterostyrax, Pistacia and Nyssa, have been planted out in long-term evaluation plots at the U.S. National Arboretum. Additional advanced hybrids of Nyssa have been planted, and screening of older material continues, evaluating for leaf spot resistance, growth habit, and fall color. A Celtis provenance trial has been planted from germplasm collected in collaboration with arboretum taxonomists. Germplasm collection efforts continue, with extensive out planting of native Crataegus made at the woody landscape plant repository. These long-term evaluation plots will facilitate the screening and selection of diverse smaller, urban adapted trees for planting in height restricted planting areas in cities. Progress was monitored throughout this project via phone calls, emails, and meetings between research partners.