Photosynthetica

, 44:387

Different ability of three Mediterranean oak species to tolerate progressive water stress

  • F. Manes
  • M. Vitale
  • E. Donato
  • M. Giannini
  • G. Puppi
Original Papers

DOI: 10.1007/s11099-006-0040-7

Cite this article as:
Manes, F., Vitale, M., Donato, E. et al. Photosynthetica (2006) 44: 387. doi:10.1007/s11099-006-0040-7

Abstract

Inter-comparisons in the gas exchange patterns and root characteristics under both well-watered and drought conditions were done in three-years-old seedlings of three oak species (Quercus cerris L., Q. frainetto Ten., and Q. ilex L.) growing in controlled environment. Well-watered Q. cerris had greater physiological performances than other oaks, but under drought it was not able to face the water stress showing also structural modifications such as reduction of root length and average diameter. On the other hand, Q. ilex maintained root growth both in drought or well-watered soils. Moreover, it was able to keep open stomata also under water stress, although stomatal conductance (gs) was low. Q. frainetto had an intermediate position in regard to its physiological and root structural characteristics between Q. cerris and Q. ilex under drought stress. For all oaks the relationship between gs and the ratio of sub-stomatal and ambient CO2 concentration (Ci/Ca) highlighted the dynamic adaptation of gs to the increase of hydraulic resistances of leaf, stem, and roots portions, more evident during the air humidity change and progressive soil dehydration. This suggests a well-triggered above-and under-ground mechanism to endure the drought stress.

Additional key words

gas exchangeQuercusnet photosynthetic rateroot morphologyseedlingsspecies differencesstomatal conductance to water vapourtranspirationxylem

Abbreviations

Ca

ambient CO2 concentration

Ci

sub-stomatal CO2 concentration

E

leaf transpiration rate

gs

stomatal conductance to water vapour

PN

net photosynthetic rate

PPFD

photosynthetic photon flux density

RH

relative humidity

VPD

vapour pressure difference

Ψ

leaf water potential

Copyright information

© Institute of Experimental Botany, ASCR 2006

Authors and Affiliations

  • F. Manes
    • 1
  • M. Vitale
    • 1
  • E. Donato
    • 1
  • M. Giannini
    • 1
  • G. Puppi
    • 1
  1. 1.Department of Plant BiologyUniversity of Rome “La Sapienza”RomeItaly