Clonal Propagation of Woody Species

Tissue-culture technology is widely used for the vegetative propagation of selected plants in agriculture and horticulture and, to a lesser extent, in forestry. The objective is to produce large numbers of plants with uniform quality. Historically, commercial applications of this technology were restricted to herbaceous plants. However, for the last two decades, considerable success has been obtained with woody plants (1 ,2 ). These include both gymnosperms and angiosperms, i.e., softwoods and hardwoods, and both trees and shrubs. Economically, these trees are extremely important for wood products, including lumber, pulp and paper, forestry plantations, and reforestation. Large-scale clonal systems can be an asset for selected high-performance trees, and reliable protocols are necessary for further genetic manipulation. However, a major problem in the propagation of woody plants is that most success is achieved with juvenile tissue and not from proven mature trees (3 ,4 ).