|ELLIS, DAVID - International Potato Center|
|WIDRLECHNER, MARK - Iowa State University|
Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/31/2019
Publication Date: N/A
Technical Abstract: Beyond landscape applications, willow (Salix spp.) is an emerging lignocellulosic crop producing biomass as a source of energy and fibers. Intense research on willow improvement and development of mechanical cultivation and harvest techniques is underway in several countries (e.g., United Kingdom, Australia, Ireland and the U.S.). Salix trees and shrubs may be grown on marginal land as a short-rotation coppice and are easily propagated by rooted cuttings in new field stands. Mass cultivation of any crop often makes a crop vulnerable to diseases and pests; hence, preservation is critical in maintaining genetic resources for future use. The USDA-ARS, National Plant Germplasm System maintains 62 accessions (33 taxa) at its Ames, Iowa location. For three years, the Agricultural Genetic Resources Preservation Research Unit in Fort Collins, CO, tested eight of these accessions for cryopreservation of dormant buds (DB) by using a modified DB technology developed for apples. The modification included longer DB twig segments (10 and 6 cm vs. 3.5 cm in the apple protocol), no desiccation of DB segments and viability testing in a sterile soil substrate (instead of grafting) after exposure to liquid nitrogen vapor (LNV; -182 to -196oC). Post-cryopreservation viability evaluated as the ability to develop leaves and/or shoot(s) ranged from 43.9 to 82.2% for 6 and 10 cm DB segments respectively, varied between years and species, and was positively correlated with shoot and root development ability in the initial (not LNV exposed) DB segments and with the twig diameter. The results suggest the possibility of cryopreserving willow genetic resources by using our modified DB method; and, in this way, 42 accessions have already been successfully cryopreserved. We suspect that the same procedure could be applicable for long-term preservation of other industrial woody crops (e.g., aspen, eucalyptus, maple, birch).