The present work aimed to evaluate the water deficiency effect and two graftings on the gas exchange of vine cuttings under greenhouse conditions. 'Niágara Rosada' (Vitis labrusca) was used as scion, and 101-14 (V. riparia x V. rupestris) and 1103 Paulsen (V. rupestris x V. berlandieri) were used as rootstocks. Twelve days after watering suspension, the leaf water potential of the combination 'Niágara Rosada'/101-14 showed lower (-2.80 MPa) in relation to 'Niágara Rosada'/1103 Paulsen (-2.10 MPa) in the non-irrigated plants, while relative water content altered only among watering levels. With the progress of water stress, there was a marked reduction in the gas exchange of the cultivar 'Niágara Rosada', which presented values close to zero, due to stomatal closure, without differences among the rootstocks. Only after twelve days without water the rootstocks influenced water use efficiency and photochemical efficiency of photosystem II, where the combination 'Niágara Rosada'/101-14, presented lowest values to 1103 Paulsen. However, during water removal, the rootstock did not influence gas exchange of the 'Niágara Rosada', showing the same behavior in water deficiency.
Vitis labrusca; water deprivation; photosynthesis; fluorescence
