The Forest Products Commission of Western Australiamanages a sandalwood (Santalum spp.) core germplasmcollection at Kununurra in the states far north. This collectionserves as a significant seed source for sandalwoodplantations in the area and remains an importantresource for ongoing research. The collection containsS. album trees sourced from Indian arboreta, along witha few trees from West Timor, Indonesia. Also presentare representatives of S. macgregorii from Papua NewGuinea and S. austrocaledonicum from Vanuatu and/orNew Caledonia. Despite the apparently diverse seed origins,the genetic background of many of the accessionsremains vague. In this study, diversity and relatednesswas assessed by nuclear and chloroplast RFLPs and aphylogeny was inferred. Nuclear RFLPs revealed verylow levels of genetic diversity for a tree species, with anobserved and expected heterozygosity (Ho and He) of0.047. Nineteen genotypes were identified within the233 S. album individuals sampled, with only one treeknown to have originated from Timor being differentiatedfrom Indian material. Other trees thought to havecome from Timor grouped with those believed to be fromIndia, indicating they were either incorrectly labelled orsourced from heavily modified populations. Despite thepoor sample size, chloroplast RFLP analysis revealed nogenetic distinction between the Timorese and IndianS. album, which supports the theory of human mediatedseed dispersal from Timor to India. The structure of thephylogeny and associated relatedness has assisted inthe establishment of seed orchards, designed to ensuremaximum diversity is maintained through limiting theproximity of highly related trees. Finally, in light ofthese and other findings, a hypothesis concerning theevolution of S. album is proposed.
|Journal||Silvae Genetica: Zeitschrift fuer Forstgenetic und Forstpflanzenzuechtung|
|Publication status||Published - 2009|