Tropical forest genetics at the Oxford Forestry Institute : Exploration, evaluation, utilization and conservation of genetic resources

Abstract

Research and development of tropical tree genetic resources began at the Oxford Forestry Institute (OFI) in 1963 with Pinus caribaea. The sequence started with exploration of the natural distribution, a study of variation through classical taxonomic procedures backed up by chemotaxonomy and isozyme analysis, and observations on general morphology. Seed was collected to cover the range of variation, then processed, tested and stored in England, and distributed for trial at representative sites and in recommended designs. Standardized assessment techniques were developed and evaluation of the field trials was conducted by OFI staff for a selection of sites and by national staff in the other locations. Following analysis, interpretation and publication of the data, second-stage seed collections were made from the most promising natural populations and scions were collected from selected phenotypes in the provenance trials themselves; these scions were shipped to Oxford and bulked through grafting, and will eventually be transferred to field sites as packaged seed-orchards and breeding populations through scions and micropropagules. The second sampling was structured to gain a better understanding of variation in the promising provenances. Appropriate breeding strategies were evolved and practically implemented through direct advice to participating countries, and a philosophy was developed for the conservation of genetic diversity, both in situ and ex situ. This work with P. caribaea created the capability in terms of specialist staff and facilities for the full genetic development and conservation of a species. As current needs have been indicated by world forestry forums, more species have been brought into the programme including other tropical pines (for example P. oocarpa, P. tecunumanii), various tropical and sub-tropical timber hardwoods (e.g. Cedrela and Cordia species) and dry-zone species for multipurpose use in agroforestry and silvo-pastoral systems (including Gliricidia, Leucaena and Parkinsonia species from central America and Acacia species from eastern Africa). During the past 25 years, the OFI has distributed over 22 000 separate seedlots of 108 species to 122 countries. Many overseas graduate students have used material from these trials for their research degrees. All records of origin, distribution, assessment and literature for each seedlot are maintained in a computerized database. Expansion of the OFI's gel-electrophoresis and tissue-culture laboratories are seen as important steps to increase the efficacy and speed with which tree species can be conserved and bred in the future.