In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

293Infusions of fresh genetic material into the breeding population mayalso be needed to meet potential demands for special breeding programmessuch as to improve resistance to pests and diseases or to increase wood density.Larger provenance resource stands that would serve as a genetic pool forfuture use must therefore be established to handle such demands. Theseprovenance resource stands can be block plantings of each provenance thatcontain as much genetic variation as possible, and only very light thinnings arerequired for these stands. Broad sampling or random seed collections withineach provenance will also be conducted to provide for the next generation ofconservation stands.Currently, MHP keeps the SPAs as well as the SSOs established fromthe former Subanjeriji material, and the total area for this material is around 40hectares. When we are very sure that we have secured the best geneticmaterials both for seed production and gene conservation, and the total area ofimproved seed sources is adequate to support our annual planting programme,we will eliminate the Subanjeriji material. The provenance trial stands thatcontain 20 provenances will also be kept as provenance conservation standsfor future studies.Closing RemarksMHP realises that prior selection practices that were conducted in the seedsources may have caused some traits to be eliminated from the breedingpopulation. This will lead to a narrower genetic base for the population.Therefore, as mentioned before, as a long term strategy we need to establishmore provenance resource stands of A. mangium to serve as future sources offresh genetic material that will be included in the breeding population. Materialexchange with research institutions as well as other private companies thathave strong tree improvement program must be greatly enhanced to enableeach party to continue improving the quality of A. mangium in the future.AcknowledgementWe would like to extend our gratitude to the committee of this conference forinviting us to share our experiences. We also thank the management of PT.Musi Hutan Persada for allowing the author to attend the conference and presentthis paper. Thanks also to Dr. Eko B. Hardiyanto for his review and usefulcomments on this manuscript.