EXOGENOUS POLYAMINES IMPROVE ROOTING OF HAZEL MICROSHOOTS

A strong positive effect of polyamines on rooting of microshoots of ad ult hazel (Corylus avellana L., cv. Gironell) is described. The effect of polyamines, both in the root induction solution and in the actual rooting medium, was assessed in order to study the effect on the succe ssive rooting phases. Polyamines improved rooting of indole-3-butyric acid-treated microshoots in a synergistic fashion, perhaps by favourin g a better induction of roots, with an acceleration of the response (o nly half the time required for rooting compared to the control). When applied without indole-3-butyric acid, polyamines had only a limited p ositive effect on rooting, although longer exposure times and/or highe r concentrations could increase their effect. Possible rapid uptake an d translocation of polyamines in the xylem in our system is discussed. The results offer a new approach to enhance rooting ability of specie s that are normally difficult to root.