Many woody plants produce large floral displays early in the spring when xylem transport can be variable and often reduced. To determine whether stem hydraulics impact floral water use, we quantified floral transpiration and tested whether it was correlated with stem xylem conductivity in five temperate woody species that flower before producing leaves. We measured inflorescence gas exchange, examined the relationship between diffusive conductance and inflorescence morphology, and estimated the amount of water supplied to an inflorescence by the phloem. We also tested for correlation between transpiration and native stem xylem conductivity for branches with leaves and branches with flowers. The flowers of our study species obtain most of their water from the xylem. Diffusive conductance was higher in small inflorescences, but water content and daily transpiration rates were greater for larger inflorescences. We found no correlation between floral transpiration per branch and stem xylem conductivity within species. The data suggest that inflorescence water loss during anthesis is not limited by the xylem in our study species. We highlight the impact of floral morphology on hydraulic traits and encourage exploration into temporal shifts in floral hydration.
Bibliographical noteFunding Information:
The authors thank Salli Dymond, Amanda Grusz, Erin O’Connell, Adam Roddy and three anonymous reviewers for feedback on the manuscript, and Kennedy Mosher and Thomas Kiecker for their help with data collection. Financial support came from the Integrated Biosciences Graduate Program (NM) at the University of Minnesota Duluth, the Corliss Knapp Engle Scholarship from the Garden Club of America (NM), the BURST Research Program at the University of Minnesota Duluth (AP), and the National Science Foundation, IOS 1656318 (JAS).
© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation
- floral size
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.