Polyamine content and metabolism as markers of in vitro organogenesis in cotyledon explants of Solanum melongena

In the present work changes in free and conjugated polyamine titres were determined in in vitro cultured cotyledon explants of S. melongena L. growing either a) in the presence of auxin (NAA), b) in the presence of NAA plus a cytochinin (zeatin riboside, ZR), c) in the absence of exogenous hormones (control). In these explants, NAA induces the formation of adventitous roots, and NAA + ZR the formation of vegetative buds; on hormon-free medium there is no organ differentiation. The appearence of roots and buds was monitored during time in culture and a histological study was performed in order to determine the site and developmental sequence of organ initiation and development.