Submitted to: Plant Genetic Resources Newsletter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 2005
Publication Date: September 20, 2006
Citation: Smith, J., Oliphant, J.M., Hummer, K.E. 2006. Plant exploration for native hop in the southwestern united states. Plant Genetic Resources Newsletter. 147:29-37. Interpretive Summary: Two plant exploration trips occurring from September 9 to 20, 2002, and from September 8 to 19, 2003, collected seeds and plants of wild hops from Colorado, Arizona and New Mexico. Wild hop plants are not common in these states. The hop plants tend to grow with large distances between them on the “mountain islands” of the southwest. Hop breeders are interested in new sources of plants that are resistant to pests and diseases. These wild hops from the western United States may have these qualities, and were not previously available for use in breeding programs. These trips produced 58 representative live hop samples from Colorado, 12 from Arizona, and 15 from New Mexico. They were deposited at the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, and are available to researchers upon request.
Technical Abstract: Hop, Humulus lupulus L., distribution in the western United States is scattered and uncommon. Two plant collecting expeditions, on 9 to 20 September 2002 and 8 to 19 September 2003, obtained genetic resources of wild American hop (Humulus lupulus var. neomexicanus Nelson and Cockerell) germplasm from Colorado, Arizona, and New Mexico. While herbarium locality data provided a starting point to search for population sites, predictors based on associated species, topography, or proximity to water source were inconsistent as locators, particularly in Arizona and New Mexico. In Colorado, populations of this hop variety were more fragmented on the eastern compared to the western slope of the Rocky Mountains. The expeditions sampled 48 populations of H. l. var. neomexicanus from 18 major drainage basins, resulting in 58 accessions from Colorado, 12 from Arizona, and 15 from New Mexico. Herbarium specimens collected from 9 new localities were distributed to major regional herbaria. The living accessions were deposited in the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Clonal Germplasm Repository (NCGR), in Corvallis, Oregon, and are available to researchers upon request.