Free polyamine variations in rooting of Vitis rootstock 140 Ruggeri

The rooting of Vitis (rootstock 140 Ruggeri) woody cuttings, collected in field from mother plants over a five-month period (October 1999-February 2000), was recorded from 0 to 60 days of basal heating. The material was collected directly in field and/or submitted to different treatments: A) cold treatment of the shoots at 2°C in cold chamber from October; b) dipping in water at the bottom end of the cuttings. Both treatments were able to modify rooting time and amount. During basal heating, at 0, 20, 40 and 60 days, rooting percentage was recorded; concomitantly, from the basal end of cuttings, free-polyamines were extracted to evaluate their endogenous levels. Results show that positive variations in rooting, induced by the treatments, are related to increases in free-polyamine levels, suggesting that an increase in the endogenous putrescine could be correlated with pri-mordia formation time. The pattern of spermine variations appears to be similar to that of putrescine, while spermidine does not appear to be correlated to the rooting process. Both spermine and spermidine amounts are present at far lower levels than putrescine.