IN-VIVO GRAFTING AND IN-VITRO MICROGRAFTING OF ACACIA-MANGIUM - IMPACT OF ORTET AGE

The possibilities of vegetatively propagating juvenile - 6-month-old - and mature - 3 to 5 year-old - Acacia mangium ortets by grafting were investigated using in vivo and in vitro techniques. The average succe ss rates obtained for in vivo top-cleft grafting were 49% for scions c oming from juvenile plant material and 0% when collected from mature o rtets. In vitro micrografted apices gave rise to 52% and 46% of succes sfully established micrografts for the juvenile and the mature plant m aterial respectively. No significant difference between juvenile and m ature origins in terms of grafting success was observed for in vitro m icrografting of shoot apices. However, the ones coming from the juveni le ortets elongated more readily than those from the mature origin whi ch were more prone to rest. Overall, the in vitro micrografting techni que used appeared to be an helpful tool for vegetative non-destructive propagation of mature selected Acacia mangium ortets, apparently reca lcitrant to more conventional in vivo grafting techniques. These resul ts are discussed in terms of scion size and the related potential for grafting in relation to the age of the ortet.