Laurence GENY*, Nathalie OLLAT** ET J. P. SOYER***
*Université de Bordeaux I, Laboratoire des Sciences de la Vigne,
Avenue des Facultés, 33405 Talence (France).
**INRA, UREFV** et Station d'Agronomie***,
B.P. 81, 33883 Villenave d'Ornon (France).
Abstract : The study was carried out in order to compare the development of berries growing on fruiting cuttings and on vines from the field, and to evaluate this experimental system for grapevine physiology studies. The results show that the main developmental characteristics of the berries are close to those of berries from the vineyard. Fruit set is good and berry growth follows a double sigmoid curve. Final size is smaller than usual, even if seed number is higher for fruiting cuttings. The evolution of organics acids, sugar and mineral content is classical. At maturity, the berries from fruiting cuttings reach the same sugar content, but are less acidic, because the components of acid equilibrium are slightly modified. At flowering polyamine content is higher in the cluster of fruiting cutting but the variations along cluster development is the same than in the vineyard. Finally the application of exogenous putrescin on fruiting cuttings at flowering time improves fruit set, as in the field. Our data allow to conclude that fruiting cuttings behave mostly as bigger vines and could be a usefull tool for grapevine physiology studies.
Key words : Fruiting cutting, Vitis vinifera, berry, cluster, polyamines, sugars, organic acids, nutrient supply.