© 2007 Heron Publishing—Victoria, Canada
Xylem vulnerability to cavitation varies among poplar and willow clones and correlates with yield
Hervé Cochard (1, 2), Eric Casella (3) and Maurizio Mencuccini (4)
1. UMR547 PIAF, INRA,University Blaise Pascal, F-63100 Clermont-Ferrand, France / 2. Corresponding author (cochard@clermont.inra.fr) / 3. Forest Research, Biometrics Division, Farnham, GU10 4LH, U.K. / 4. School of GeoSciences, University of Edinburgh, EH9 3JN, U.K. / Received January 11, 2007; accepted April 19, 2007; published online September 4, 2007
Summary
Xylem vulnerability to cavitation is a promising criterion for identifying trees with high drought tolerance, but traditional
techniques for measuring cavitation resistance are unsuitable for screening large numbers of genotypes. We tested the potential
of the new Cavitron technique for high throughput screening of cavitation resistance in five poplar (Populus spp.) and four willow (Salix spp.) clones. The Cavitron technique enabled the screening of three to four clones per day with sufficient accuracy to reveal
significant differences between clones. Because intraspecific screening may be better carried out through the identification
of correlated and more easily measured traits, we attempted to identify accessible parameters that correlate to cavitation
resistance. Variability in vulnerability to cavitation across clones was poorly correlated with anatomical traits such as
vessel diameter, vessel wall strength, wood density and fiber wall thickness; however, a striking correlation was established
between cavitation resistance and aboveground biomass production, indicating a possible trade-off between xylem safety and
growth potential.
Keywords:
drought resistance, embolism, genotypic variability, xylem physiology.
