Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/16/2013
Publication Date: 8/11/2013
Citation: Jenderek, M.M., Ambruzs, B.D., Tanner, J.D., Holman, G.E., Ledbetter, C.A., Ellis, D., Leslie, C., Coggeshall, M. 2013. Progress in cryopreservation of dormant winter buds of selected tree species. Meeting Abstract. 2nd International Symposium on Plant Cryopreservation, Fort Collins, CO, August 11-16, 2013. pp. 37. Interpretive Summary:
Technical Abstract: In cryopreservation of germplasm, using dormant winter buds (DB) as source plant materials is economically favorable over tissue culture options (TC). Processing DB does not require aseptic conditions and involved cryopreservation procedures. Although, the DB cryopreservation method has been known for many years, the approach is feasible only for cryopreserving a select number of temperate tree species. The original method developed for Malus (apple) DB, requires material desiccation (to 25-30 % moisture content), slow cooling (to ca. -30oC), storage in liquid nitrogen (LN) and viability testing after cryostorage. Viability testing is done by grafting onto rootstock or by rooting the cryopreserved DB (applicable only to a few species). We investigated the possibility of using this method for cryopreservation of DB of selected species of Juglans, Prunus and Salix germplasm (2, 2 and 14 species respectively) with some modifications. In J. nigra (black walnut) and J. regia (English walnut), cold-hardening (2oC, 4 days) under two different light regimes and DB pretreatment with ABA or sucrose solutions has not increased post cryo viability. The viability after LN exposure of P. armeniaca (apricot) and P. dulcis (almond) DB, was very low but heavily dependent on the budwood harvest time. Cryopreserved Salix DB on 10 cm branch segments developed shoots in a higher percentage than DB on 7 cm long segments (68.5-100 and 50-100 % respectively); this indicates that the longer segments may be better suited for cryopreservation of the Salix germplasm. For the two Juglans species, the post cryo viability was evaluated by forced bud breaking under mist conditions. LN exposed DB of black walnut were viable 60-100 %, English walnut 10-60 % whereas the viability of the controls (DB stored at -5oC) was 62.5-100 and 80-100% respectively. Evaluation of viability by forced bud breaking may not be applicable for revival of cryopreserved material into functional plants but is an informative indication of cryogenic survival. Studies on a correlation between viability tested by grafting and under mist are in progress.