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Measurement of vulnerability to water stress‐induced cavitation in grapevine: a comparison of four techniques applied to a long‐vesseled species
Author(s) -
CHOAT BRENDAN,
DRAYTON WILLIAM M.,
BRODERSEN CRAIG,
MATTHEWS MARK A.,
SHACKEL KEN A.,
WADA HIROSHI,
MCELRONE ANDREW J.
Publication year - 2010
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2010.02160.x
Subject(s) - xylem , dehydration , cavitation , water stress , hydraulic conductivity , centrifuge , air embolism , embolism , stress (linguistics) , materials science , chemistry , horticulture , nuclear magnetic resonance , environmental science , biology , soil science , medicine , surgery , physics , acoustics , biochemistry , linguistics , philosophy , soil water , nuclear physics , complication
Among woody plants, grapevines are often described as highly vulnerable to water‐stress induced cavitation with emboli forming at slight tensions. However, we found native embolism never exceeded 30% despite low xylem water potentials ( Ψ x ) for stems of field grown vines. The discrepancy between native embolism measurements and those of previous reports led us to assess vulnerability curve generation using four separate methods and alterations (i.e. segment length and with/without flushing to remove embolism prior to measurement) of each. Centrifuge, dehydration and air‐injection methods, which rely on measurement of percentage loss of hydraulic conductivity (PLC) in detached stems, were compared against non‐invasive monitoring of xylem cavitation with nuclear magnetic resonance (NMR) imaging. Short segment air‐injection and flushed centrifuge stems reached >90 PLC at Ψ x of‐0.5 and −1.5 MPa, respectively, whereas dehydration and long‐segment air‐injection measurements indicated no significant embolism at Ψ x > −2.0 MPa. Observations from NMR agreed with the dehydration and long segment air‐injection methods, showing the majority of vessels were still water‐filled at Ψ x > −1.5 MPa. Our findings show V . vinifera stems are far less vulnerable to water stress‐induced cavitation than previously reported, and dehydration and long segment air‐injection techniques are more appropriate for long‐vesseled species and organs.