Trees II : Springer : 9783540191582 : 3540191585 : 24 Jan 1989 : 'frees contribute a major part of fuel, fodder and fruit, and are an im­ of bioenergy. They are now needed in large numbers more portant source than ever before for afforestation and social forestry, so that fast-grow­ ing and multipurpose trees assume great importance. After extensive in­ discriminate deforestation and rapid depletion of genetic stocks, efforts are now being made to evolve methods for clonal mass propagation of improved and elite trees. Production of short-duration trees with a rapid turnover of biomass, and induction of genetic variability through in vitro manipulation for the production of novel fruit and forest trees, which are high-yielding and resistant to pests and diseases, and trees which display increased photosynthetic efficiency are in demand. These objectives are well within the realm of horticultural and forest biotech­ nology. Some of the recent advances, such as the regeneration of com­ pl