
%0 Journal Article
%A Osório, Júlio 
%A Osório, M. Leonor 
%A Chaves, M. Manuela 
%A Pereira, Jo&atilde;o S. 
%T Effects of water deficits on <emph type="7">13</emph>C discrimination and transpiration efficiency of <emph type="2">Eucalyptus globulus</emph> clones
%J Functional Plant Biology
%D 1998/10/26
%V 25
%N 6
%P 645-653
%K Eucalyptus, water stress, transpiration efficiency, carbon isotope discrimination.
%R https://doi.org/10.1071/PP97167
%U https://www.publish.csiro.au/paper/PP97167 
%X 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. 
