A technique for measuring xylem hydraulic conductance under high negative pressures |
| |
Authors: | H Cochard |
| |
Institution: | UMR PIAF, INRA-UniversitéBlaise Pascal, site de Crouelle, 63039 Clermont-Ferrand, France |
| |
Abstract: | A technique for measuring hydraulic conductances of excised xylem segments exposed to high negative pressures is described. A centrifugal force is used to generate negative pressures (P) in the sample and to create a positive hydrostatic pressure difference (ΔP) between its two ends. ΔP forces water through the sample at a flow rate (F) determined optically during centrifugation. The sample hydraulic conductance k is derived from F and ΔP. The sample vulnerability curve is given by the dependence of k on P. Results for Cedrus atlantica Manetti and Laurus nobilis L. shoots are given. The technique is appropriate for the analysis of xylem refilling under negative pressure. |
| |
Keywords: | Laurus nobilis L cavitation centrifugation embolism water relations |
|
|