Tree breeding

Tree breeding is the application of genetic principles to the genetic improvement and management of forest trees. In contrast to the selective breeding of livestock, arable crops, and horticultural flowers over the last few centuries, the breeding of trees, with the exception of fruit trees, is a relatively recent occurrence.

A typical forest tree breeding program starts with selection of superior phenotypes (plus trees) in a natural or planted forest. This improves the genotypes somewhat. Offspring is obtained from selected trees and grown in test plantations. Based on such tests the best genotypes among the parents can be selected. Selected trees are typically multiplied by grafting and seed orchards are established when the preferred output is improved seed. Alternatively, the best genotypes can be directly propagated by cuttings or in-vitro methods and used directly in clonal plantations. The first system is frequently used in pines and other conifers, while the second is typical in broadleaves (poplars, eucalypts and others). The objectives of a breeding tree program range from yield improvement and adaptation to particular conditions, to pest-resistance, wood characters etc. Currently, tree breeding is gaining new interest under the threat of Global Warming, and it is taking advantage of the fast development in plant genetics and genomics.

Selected bibliography

• 2007 Gösta Eriksson, Inger Ekberg and David Clapham. An Introduction to Forest Genetics. ISBN 91-576-7190-7 [1]
• 1984. Applied Forest Tree Improvement. Bruce Zobel, John Talbert, North Carolina State University, John Wiley and Sons, Inc, ISBN 0-471-09682-2