Genetic diversity of endangered sandalwood (Osyrislanceolata) populations in Kenya using ISSR molecularmarkers

Abstract

Osyris lanceolatais an evergreen, drought tolerant tropical Africantree species belonging to the family Santalaceae. It is endangered,owing to overexploitation for its essential oil used in cosmetics andpharmaceutical industries. The study aimed at determining: (1) thegenetic diversity; and (2) the population genetic differentiation inseven keyO. lanceolatapopulations, representing its naturaldistribution in Kenya. Genotype data for ISSR neutral molecularmarkers were generated for seven populations ofO. lanceolata.Thepercentage of polymorphic loci (P),ranged from 51% (Wundanyi)to 82% (Gwasii), with a mean of 65%. The mean number ofeffective alleles (Ne) was 1.430, whereas the Shannon InformationIndex (I) mean was 0.263. Gwasii population was the mostgenetically diverse followed by Mt Elgon and least was Wundanyi.The coefficient of differentiationGstwas 0.343. Results of analysisof molecular variance (AMOVA) showed that most of the geneticvariation (62%) inO. lanceolataresided within populations. Principalcoordinate analysis (PCoA) analysis showed that Baringo populationlocated in the Rift Valley was genetically distinct from the rest ofthe populations. In conclusion, Gwasii, Mt Elgon and Baringopopulations should be delineated forin situconservation, whereasselection forex situconservation should target good trees from allthe populations