This overview of various aspects of plant molecular biology that are relevant to the improvement of woody plants, is divided into two volumes. In Volume 1, background information on genetic engineering and molecular marker techniques is emphasized, whereas Volume 2 contains specific examples of species in which sufficient progress has been made. The first few chapters in Section 1 of Volume 1 focus on the current status of transgenic expression in plants and molecular aspects of development in woody plants, while the latter half of this section includes chapters on molecular biology of cell wall biosynthesis and nitrogen metabolism. Section 2 of Volume 1 covers tissue culture of woody plants and its relevance to molecular biology research, and the role of molecular markers in evolution, genome mapping, and aiding in breeding programmes for the selection of desired genotypes. Volume 2 covers general aspects of the technology of gene transfer in woody plants and several examples of the applications of the techniques of molecular biology to woody species.