BIOTECHNOLOGY IN "REJUVENATION": HOPE FOR THE MICROPROPAGATION OF DIFFICULT WOODY PLANTS
The main reason is our inability to manipulate the phase changes which caracterise the development of woody plants. For fruit and broadleave trees, usual operating process of micropropagation is inducing what could be considered as an excess of rejuvenation whose negative effects are "vitrification" in vitro and retarded fructification outdoor.
On the contrary for trees without coppicing aptitude, it is the lack of rejuvenating effect which limits the part of micropropagation in the reproduction of the selected forest trees.
The first manipulations of developmental phases were initiated around 1950 exsitu, with horticultural methods.
It is around 1980 that the new biotechnologies begin to improve our methods of rejuvenation thank to set of better markers of juvenility or maturation.
To date, molecular genetics, immunomethods, enzymology, mineral and biochemical analysis of microsamples of tissues or cells are promising of a very fast improvement in our efficiency to micropropagate adult and difficult trees.