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 Printable version |
Three simple genetic breeding and conservation methods for agroforestry and forestry in arid lands |
Science et changements planétaires / Sécheresse. Volume 19, Number 4, 269-75, octobre-novembre-décembre 2008, Article de recherche
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 Résumé
Article gratuit
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Author(s) : Alphonse Nanson |
Summary : Desertification is expending rapidly due to global warming and to increasing human pressure. Many agroforest- and forest species are threatened and need to be protected through conservation practices. A part of them should also rapidly be improved to offer a better service to local human populations but resources are lacking. Due to the large number of species involved, classical and expensive breeding programmes are inadequate. Simple and cheap but still effective programmes have to be found. Present classical methods of Tree Breeding include Provenance testing, Seed Stand selection and Individual selection. The proposed strategy is composed of three simple methods, the first two of which merge the three classical methods. The first consists in thoroughly mixing the seeds of many supposedly good provenances or varieties to constitute a stand in a given Breeding Region. This stand is then submitted to successive selective thinnings that improve its genetic value and its adaptation. Seed for afforestation is collected from this stand. The second method is the Provenance Seedling Seed Orchard. It follows the same procedure, except that the identity of every plant is maintained, permitting diverse scientific analyses and opening the way to a further refined Individual selection. The third is that of the recurrent Seed Stands with options combined with the first method. In either case, heterotic breeding populations already adapted to the considered Breeding region and endowed with very large genetic biodiversity are built up. In subsequent generations, the adaptation of these populations continues to improve. As well as Agroforest- and Forest Tree Breeding, Gene conservation can thus be achieved rapidly, simply and at low cost for many species. These methods provide robust populations much better adapted to extreme and changing environments. It is a new tool to combat desertification. |
Keywords : agroforestry, breeding, conservation, desertification, forestry |
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