1a.Objectives (from AD-416):
To perform plant explorations in the Pacific Northwest of the United States to collect seeds and leaf tissues of Malus fusca. Materials collected will be analyzed for genetic diversity within and among populations and seeds will be provided to the Plant Genetic Resources Unit in Geneva, NY for the National Plant Germplasm System.
1b.Approach (from AD-416):
Collections of Oregon Crabapple (Malus fusca) wild populations will contribute novel, desirable genetic resources to the National Plant Germplasm System. Seeds and plants will be provided to the USDA-ARS Plant Genetic Resources Unit Apple collection in Geneva, NY. Genetic diversity of individuals identified during collection trips will be compared with that of other wild apple populations.
The SCA project titled "Plant Collection and Diversity Analyses of Malus Fusca" with the University of Arizona has resulted in the collection of dozens of seedlots that will be deposited in the Malus collection of the National Plant Germplasm System. Genetic diversity of the wild Pacific Crabapple (Malus fusca) was determined using leaf samples collected in California, Oregon and Washington and herbaria samples from British Columbia and Alaska. Overall, Malus fusca has less genetic diversity (based on microsatellite analyses) than wild apple species Malus orientalis and Malus sieversii from Central Asia.
Trees in the National Plant Germplasm System appear to represent the diversity of the wild populations, although a few more accessions from the northern regions of the species range might capture some northerly adapted ecotypes. This research will be published: Genetic variation and distribution of Pacific crabapple, Malus fusca, (Raf.) C.K. Schneid. Log #281972 Journal of the American Society for Horticultural Science (In press).