Journal Article

Nutrition, xylem cavitation and drought resistance in hybrid poplar

H. P. Harvey and R. van den Driessche

in Tree Physiology

Volume 17, issue 10, pages 647-654
Published in print October 1997 | ISSN: 0829-318X
Published online October 1997 | e-ISSN: 1758-4469 | DOI: http://dx.doi.org/10.1093/treephys/17.10.647
Nutrition, xylem cavitation and drought resistance in hybrid poplar

Show Summary Details

Preview

Effects of mineral nutrition on susceptibility to cavitation were examined in four hybrid poplar clones. Two drought-sensitive and two drought-resistant hybrid clones of black cottonwood (Populus trichocarpa Torr. & Gray) and eastern cottonwood (P. deltoides Bartr.) were grown at three concentrations of nitrogen (N) applied factorially with two concentrations of phosphorus (P) in a greenhouse, and subjected to varying degrees of drought stress before measurement of cavitation and of anatomical features that might affect cavitation. Mean vessel pit pore diameters were 0.132 μm at low P, and 0.074 μm at high P, but no other significant effects of mineral nutrition on vessel dimensions were observed. Vessel diameter and specific conductivity were greater in the drought-resistant clones than in the drought-susceptible clones. Drought-resistant clones did not reach such low water potentials as drought-sensitive clones during the cavitation induction experiments, suggesting better stomatal and cuticular control of water loss. Scanning electron microscope observations showed less damage to pit membranes, also suggesting greater membrane strength in drought-resistant clones than in drought-sensitive clones. High concentrations of N increased cavitation, whereas high concentrations of P decreased cavitation as measured by both hydraulic flow apparatus and dye perfusion techniques. For one test, cavitation was 48% at high N and low P, but only 28% at high N and high P. We consider that N fertilization may make poplars more susceptible to cavitation on dry sites, but P fertilization may reduce this effect.

Keywords: cottonwood; embolism; hydraulic conductivity; nitrogen; phosphorus; Populus

Journal Article.  0 words. 

Subjects: Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.