Development of rejuvenation methods for in vitro establishment, multiplication and rooting of mature trees.

The utility of the micropropagation of forest trees is limited by the efficiency with which selected trees can be reproduced vegetatively. As is well known, there are several woodland species for which satisfactorily successfull establishment in vitro has still not been achieved, at least for adult trees. Juvenile trees are in general readily cloned by conventional techniques, but the ease of propagation of many trees tends to diminish as they approach a size sufficient to allow reliable evaluation of their crop potential (Bonga, 1987).