Noble Hardwoods. EUFORGEN Genetic Conservation Network

Abstract

The EUFORGEN network on noble hardwoods was established in 1996 and formulated at its first meeting the objective as follows: Identification of minimum gene conservation activities in the long term from a European perspective. A more specific formulation of the objective is: To safeguard the evolutionary potential of a species. Another objective valid for wild relatives of domesticated fruit tree species is to preserve their present genetic constitution. Since the genetic knowledge is scanty for most noble hardwoods the gene conservation methods have to a large extent be based on educated guesses about genetic differentiation among populations as well as the dynamics of the populations. For most commonly occurring species the in situ version of the Multiple Population Breeding System (MPBS) is suggested. MPBS means that the gene resource population is split into 20-30 subpopulations, each with an effective population size of at least 50 trees. Species with wide pollen dispersal will have the lower number of populations whereas species with limited pollen dispersal require more populations. Gene conservation in low hedges of elms is a method that prevents the attacks of the vector of the serious Dutch elm disease. For rarely occurring species establishment of clone archives to increase the effective population size is suggested. In most cases there will be no funding for such an expensive gene conservation. For these cases delivery of seedlings free of charge is an alternative. Many of the rarely occurring species are secondary species in an ecosystem and as such suffer from competition from climax species. Alleviation of this competition by thinning of the competing species is useful. The recommendations by the network should be regarded as a minimum from a European perspective and each country can complement with more gene resource populations.