Management and development of agroforestry germplasm in the tropics: an orientation

Abstract

Whereas in the agronomic and horticultural sectors the importance of the germplasm used is widely appreciated, the same is not true in agroforestry. In the present article, the importance of adequate management of genetic variation is explained and some common approaches to development and choice of agroforestry germplasm sources are described. First, some examples of genetic variation in agroforestry trees are presented (geographic variation, within-population variation, variation between alternative sources of exotic species, superiority of local races), together with examples of some problems that may ensue when genetic variation is deficient (inbreeding depression, genetic vulnerability). Subsequently, the main types of improved germplasm source used in agroforestry (clonal multiplication gardens, seed orchards, seed stands) are briefly described. In the third section, three tools (in the form of dichotomous keys), aimed at facilitating the choice and development of germplasm sources, are presented. Finally, some implications of climate change far the selection and development of agrofarestry germplasm sources are considered.