Effect of forest tree domestication on gene pools.

Abstract The little available information on the domestication of forest tree species is mainly devoted to the genetic consequences of domestication rather than the process itself. Domestication of forest tree species is fragmented and follows the classical horizontal organization of management systems, thus making evaluation difficult. However, systematic monitoring of the various steps of the domestication process (selection-breeding methods and strategies, and seed and seedling production) has identified cases of unintentional directional selection where genetic diversity could be affected. Phenotypic selection has been proven effective in capturing most of the genetic variation existing in natural populations. The progress from breeding population to production populations did not substantially reduce genetic variability; however, the chance for rare, endemic allelic loss increased with a reduction in number of parental trees in seed orchards. Use of a breeding strategy that provides for sampling over several geographical locations and selection for various goals, as well as adaptation to different environments (i.e. Multiple Population Breeding System) was demonstrated to be effective. Generally, understanding the species biology and the role of biology on genetic diversity is of great importance. The need for change and/or the implementation of management practices is effective in maintaining the genetic variability.