Free Access
| Issue |
Ann. For. Sci.
Volume 57, Number 4, May 2000
|
|
|---|---|---|
| Page(s) | 305 - 312 | |
| DOI | https://doi.org/10.1051/forest:2000121 | |
DOI: 10.1051/forest:2000121
Ann. For. Sci. 57 (2000) 305-312
Influence of the ectomycorrhizas formed by Tuber melanosporum Vitt. on hydraulic conductance and water relations of Quercus ilex L. seedlings
Andrea Nardinia - Sebastiano Salleoa - Melvin T. Tyreeb - Moreno Vertoveca
aDipartimento di Biologia, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italia
bUSDA Forest Service, Northeastern Experiment Station, 705 Spear Street, Burlington, VT 05402-0968, USA
(
Abstract:
The physiological impact of ectomycorrhizal infection was investigated in the association
between Tuber melanosporum Vitt. and Quercus ilex L. A number of physiological parameters
were investigated on 2-year-old seedlings inoculated for 22 months (I-seedlings) compared to
non-inoculated plants (NI-seedlings). I-seedlings had a 100% infection rate in root tips
compared to a 25% infection rate in root tips of NI-seedlings. I-seedlings had higher values
of net assimilation and stomatal conductance than NI-seedlings. Root hydraulic conductance
per unit root surface area of I-seedlings was much reduced to 0.44
that of NI-seedlings but
had 2.5
more fine root surface area than NI-seedlings. When root conductance was scaled by
leaf area, the I-seedlings had 1.27
the root conductance per unit leaf area compared to
NI-seedlings. I-seedlings also had significantly higher hydraulic conductances of shoots
with leaves, of shoots without leaves and lower leaf blade hydraulic resistances.
that of NI-seedlings but
had 2.5
more fine root surface area than NI-seedlings. When root conductance was scaled by
leaf area, the I-seedlings had 1.27
the root conductance per unit leaf area compared to
NI-seedlings. I-seedlings also had significantly higher hydraulic conductances of shoots
with leaves, of shoots without leaves and lower leaf blade hydraulic resistances.
Keywords:
hydraulic conductance / water relations / ectomycorrhiza / Quercus ilex
L. / HPFM
Résumé:
Influence sur la conductance hydraulique et les relations hydriques des semis de
Quercus ilex L. des ectomycorrhizes formées par Tuber melanosporum Vitt. L'impact
physiologique dû à l'infection d'ectomycorrhizes a été étudié dans l'association
Tuber melanosporum Vitt. et Quercus ilex L. Un certain nombre de paramètres physiologiques ont
été mesurés sur des semis de 2 ans inoculés pendant 22 mois (semis-i) en comparaison avec des
cultures saines (semis-i). Les semis-i présentent 100% de taux d'infection des racines,
tandis que les semis-i atteignent un taux de 25%. Les semis-i ont des niveaux
d'assimilation nette plus élevés par rapport aux semis-i. La conductance hydraulique des
racines par unité de surface des racines pour les semis-i est réduite de plus de 0,44 fois
par rapport aux semis-i, mais comporte une surface de racines 2,5 fois inférieure à celle
des semis-i. En rapportant la conductance des racines à la surface des feuilles, la
conductance des racines par unité de surface des feuilles des semis-i est 1,27 fois plus
élevée que celle des semis-i. Les semis-i présentent également une conductance hydraulique
des rameaux avec feuilles et sans feuilles bien plus élevée, ainsi qu'une moindre résistance
hydraulique des feuilles.
Mots clé :
conductance hydraulique / relations hydriques / ectomycorrhize /
Quercus ilex L. / HPFM
Correspondence and reprints: Andrea Nardinia
Tel. +39-040-6763875; Fax. +39-040-568855; nardini@univ.trieste.it
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