Abstract
Abstract The role of scion water relations was studied using Colorado blue spruce (Picea pungens Engelmann ‘Hoopsi’) scions on Norway spruce [Picea abies (L.) Karst.] rootstocks grown either in a greenhouse or in a covered, unheated lath house. In greenhouse-grown grafts, total water potential (ψT) and relative water content (RWC) of the scions declined rapidly the first 2 weeks. Thereafter, both ψT and RWC were maintained or gradually increased in successful grafts. With scion budbreak, ψT rapidly increased to −1.0 MPa. This increase occurred 1 to 2 weeks after tracheid connections matured, based on dye movement through the graft union. At the same time, the ψT and RWC of unsuccessful grafts declined rapidly. Osmotic potentials (ψw) increased 3 weeks prior to budbreak in successful grafts. However, ψπ declined in unsuccessful grafts more rapidly than ψT, resulting in increased calculated turgor pressures with graft failure. Lath house-grown grafts had higher scion ψT and higher graft success than those in the greenhouse, but required more time for union development. Based on this data and previous work, an hypothesis relating changes in ψT, maturation of connecting tracheids, and scion budbreak to graft success or failure is presented.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the American Society for Horticultural Science
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
