Science et changements planétaires / Sécheresse


Développement d’un programme intégré d’amélioration génétique du Racosperma spp. pour le reboisement de terres marginales zaïroises Volume 6, issue 3, Septembre 1995

Centre de recherche en biologie forestière, Faculté de foresterie et de géomatique, Université Laval, Sainte-Foy, Québec G1K 7P4, Canada
  • Page(s) : 281-8
  • Published in: 1995

The implications and perspectives of an integrated gene improvement program in Zaire for Racosperma auriculiforme and R. mangium, are discussed. The two leguminous tree species are fast-growing and are used for a variety of purposes. Indigenous to Australia, Papua New Guinea and Indonesia, they were introduced into several sub-Saharan African countries including Zaire for fuelwood plantations and agroforestry systems. Allozyme markers revealed that R. mangium was genetically poorer compared to R. auriculiforme, the latter showing a geographical pattern of population differentiation. The genetic distance between the two species was low, suggesting weak reproductive isolation. For quantitative traits, genecological tests indicated that R. auriculiforme was more plastic than R. mangium, although both showing a geographical pattern of population differentiation. For both taxa, variations in rooting ability according to geographical origin were maximised under hormone treatment. A reciprocal recurrent selection scheme with controlled pollination and propagation by cuttings should make it possible to set up a hybrid breeding programme yielding new varieties for increased productivity of plantations and agroforestry systems.