EFFECT OF ETHYLENE ON IN-VITRO DEVELOPMEN T OF VITIS-VINIFERA CV UGNIBLANC

2-chloroethylphosphonic acid (ACEP) causes an inhibition of developmen t of grapevine microcuttings (Vitis vinifera L. cv. Ugni blanc), and a n increase in ethylene concentration into atmosphere of culture vessel s; when it reaches 4.1 nmoles.l(-1), growth in totally blocked. The in hibition of development is proportional to ethylene concentration. On the other hand, inhibition of ethylene action by silver ion allows in restore the development of microcuttings treated by inhibitory concent rations of ACEP. Furthermore, it has been demonstrated that microcutti ngs present a great sensitivity to ethylene only during the first days of culture.