To clarify phylogenetic relationships among New Caledonian species of Diospyros, sequences of four plastid
markers (atpB, rbcL, trnKmatK and trnStrnG) and two low-copy nuclear markers (ncpGS and PHYA) were
analysed. New Caledonian Diospyros species fall into three clades, two of which have only a few members
(1 or 5 species); the third has 21 closely related species for which relationships among species have been
mostly unresolved in a previous study. Although species of the third group (NC clade III) are morphologically
distinct and largely occupy different habitats, they exhibit little molecular variability. Diospyros vieillardii
is sister to the rest of the NC clade III, followed by D. umbrosa and D. flavocarpa, which are sister to the
rest of this clade. Species from coastal habitats of western Grande Terre (D. cherrieri and D. veillonii) and
some found on coralline substrates (D. calciphila and D. inexplorata) form two well-supported subgroups.
The species of NC clade III have significantly larger genomes than found in diploid species of Diospyros from
other parts of the world, but they all appear to be diploids. By applying a molecular clock, we infer that the
ancestor of the NC clade III arrived in New Caledonia around 9 million years ago. The oldest species are
around 7 million years old and the youngest ones probably much less than 1 million years.
