EFFECT OF IBA AND NAA TREATMENTS ON THE ENDOGENOUS HORMONES IN GRAPEVINE ROOTSTOCK HARDWOOD CUTTINGS
Hardwood cuttings of grapevine rootstocks "Kober 5BB" (easy to root) and "140 Ruggeri" (hard to root), treated at their bases with 4000 ppm IBA and 2000 ppm NAA, were bio-assayed for some of their hormones. Both treatments induced drastic modifications in the hormonal patterns at different stages of the root formation in "140 Ruggeri" and, to a lesser extent, in "Kober 5BB". Auxins doubled IAA content and induced two peaks of such hormon at the cellular multiplication at the cutting base and immediately before root emission. In general IBA and NAA promoted a GA-degradation so that, after callusing, GA-activity was no more than half of the controls. The rootstocks responded slightly different to auxins with respect to ABA. NAA induced its strong depletion in "Kober 5BB" while "140 Ruggeri" had an alternate effect. In any case both treatments prevented a rise of ABA content before root development.
Kracke, H. and Cristoferi, G. (1983). EFFECT OF IBA AND NAA TREATMENTS ON THE ENDOGENOUS HORMONES IN GRAPEVINE ROOTSTOCK HARDWOOD CUTTINGS. Acta Hortic. 137, 95-102