
TY  - JOUR
A1  - Osório, Júlio 
A1  - Osório, M. Leonor 
A1  - Chaves, M. Manuela 
A1  - Pereira, Jo&atilde;o S. 
T1  - Effects of water deficits on <emph type="7">13</emph>C discrimination and transpiration efficiency of <emph type="2">Eucalyptus globulus</emph> clones
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1998
VL  - 25
IS  - 6
SP  - 645
EP  - 653
KW  - Eucalyptus, water stress, transpiration efficiency, carbon isotope discrimination.
UR  - https://doi.org/10.1071/PP97167 
N2  - Potted cuttings of three Eucalyptus globulus Labill. clones (AR3, CN44, MP11) were grown over 6 months in a greenhouse under three watering regimes: well watered (HW), moderate soil water deficit (MS) and severe soil water deficit (SS). Transpiration efficiency (W = total dry matter/water transpired) and leaf intrinsic gas exchange efficiency (A/gs = carbon assimilation rate/stomatal conductance) increased under water stress and were positively correlated with the stable carbon isotope composition of leaf tissue (&#948;13C). The clones did not vary significantly with respect to A/gs and W. However, statistically significant differences were detected among clones in &#948;13C, A and biomass. W did not differ between the MS and SS regimes, probably due to plant acclimation to increasing soil water deficits. The increase in W with soil water deficits relative to the well watered control was primarily associated with stomatal closure, but was also influenced by differences in respiratory carbon losses (&phis;c) and variation in the leaf-to-air water vapour difference (v). Variance in &phis;c and v may explain partially why the two levels of soil water deficit were different in regard to &#948;13C but not in terms of W. 
ER  -

