USE OF CARBON-DIOXIDE ENRICHMENT TO OBTAIN ADULT MORPHOLOGY OF GRAPEVINE INVITRO

A procedure has been developed for in vitro propagation of Vitis vinifera 'Pinot noir' from lateral-bud cuttings under high CO2 concentration (1200 mumol mol-1). Because of inhibition of rooting by CO2, this procedure requires a rooting pre-culture of explants on medium with sucrose before the CO2-enriched culture on sucrose-free medium. Shoot growth was enhanced by CO2 enrichment as a result of both a higher rate of leaf production and greater internode elongation. Leaf expansion and tendril growth were promoted and better rooting was obtained. The more significant effect of CO2 enrichment was to promote adult morphology with, in particular, the tendril pattern. Thus, for the first time, grapevine plants have been produced in vitro without typical juvenile characteristics. CO2 enrichment appears to be an interesting process to improve the in vitro propagation of grapevines.