摘要：The U.S. Department of Agriculture, Forest Service, Dorena Genetic Resource Center (DGRC) has been producing whitebark pine (Pinus albicaulis Engelm.) seedlings for outplanting and for testing for resistance to white pine blister rust (caused by the exotic pathogenic fungus Cronartium ribicola) since 2000. During the past 15 years, DGRC has designed and implemented numerous studies to improve seed use efficiency and germination percentages. In 2015, three new stratification protocols were tested against operational protocols on eight seedlots from three national forests to examine differences in speed of germination and total germination. The stratification treatments included (1) 140-day stratification in sand, (2) presoak in 1,000 parts per million gibberellic acid and 140-day stratification, (3) 140-day stratification in peat moss, and (4) control (operational method). No significant difference in speed of germination among treatments was observed, but the seeds stratified for 140 days in sand had significantly higher total germination than all other treatments. This paper was presented at the annual meeting of the Western Forest and Conservation Nursery Association (Eugene, OR, October 26–27, 2015).
