Whole-plant transpiration efficiency of Sultana grapevine grown under saline conditions is increased through the use of a Cl^–-excluding rootstock

Mark R. Gibberd, Rob R. Walker and Anthony G. Condon

Abstract

The aim of this study was to test the influence of salinity (1, 20, 40 and 80 mol m^–3) on the transpiration efficiency (W = biomass / water transpired), lamina gas exchange and carbon isotope discrimination (Δ) of grapevine (Vitis vinifera L. cv. Sultana) grown on own roots or grafted to a Cl^–-excluding rootstock (Ramsey; Vitis champini L.). Growth of own-rooted and Ramsey-rooted vines irrigated with a salinity of 40 mol m^–3 was reduced by 55 and 12%, respectively, compared with vines irrigated with 1 mol m^–3. At 1 mol m^–3 W of Ramsey-rooted vines was 1.3-fold higher than own-rooted vines (3.9 and 3.0 g L^–1, respectively). Salinity resulted in a decrease in W of own-rooted vines (31% reduction at both 40 and 80 mol m^–3). In contrast, W of Ramsey-rooted vines increased by up to 1.25-fold under saline conditions. Consequently, at 80 mol m^–3 W of Ramsey-rooted vines was 2-fold higher than own-rooted vines. To our knowledge this is the first demonstration of the potential of a rootstock to increase W of a crop species under saline conditions. The rootstock-dependent differences in grapevine W under saline conditions were not determined by differences in lamina gas exchange. Differences in W associated with rootstock may be attributed to differences in ion uptake and the energy requirements associated with ion partitioning and the formation of compatible solutes.

Keywords: grapevine, photosynthesis, rootstock, salinity, transpiration efficiency, Vitis.

Functional Plant Biology 30(6) 643 - 652 (2003) doi:10.1071/FP02191