Putrescine and hydrogen peroxide improve the rooting of 'GF-677' rootstock in woody cuttings and tissue culture shoots

'GF-677', a rootstock hybrid of peach X almond, has an economic and horticultural importance in the plantation and especially in replantation of peach and other stone fruits. The rootstock cuttings are difficult-to-propagate, which constitutes a problem in supplying the rootstock demand. Putrescine and hydrogen peroxide were found to be involved in the rooting process. Therefore, their effects on rooting of 'GF-677' of in vivo and in vitro systems are being addressed. Putrescine and hydrogen peroxide doubled the percentage of the rooted 'GF-677' cuttings, relatively to IBA alone. Nevertheless, the maximal rooting percent did not exceed 27%. In the tissue culture system, in the absence of IBA in the medium, putrescine (1 mM) and hydrogen peroxide (dipping 1 M solution for 2 s) raised the explants rooting percentage from 0 to 42% and 35%, respectively. In the presence of IBA, both tested substances increased, not significantly, the rooting percentage, which was anyhow 70%. However, hydrogen peroxide increased the weight (190%), number (150%) and length (64%) of roots per explant. Putrescine increased significantly the weight (110%) and the number (106%) of roots per explant. It appears that the rooting of 'GF-677' rootstock could be significantly improved by the addition of putrescine and hydrogen peroxide to the rooting medium under in vivo and in vitro systems.