EST-SSR genotyping data from: Ecotype variation in the endemic tree Callicarpa subpubescens on small oceanic islands: Genetic, phenotypic, and environmental insights

Callicarpa subpubescens, endemic to the Ogasawara Islands, is suggested to
have multiple ecotypes in the Hahajima Islands, specifically in the
central part of the Ogasawara Islands. In this study, associations between
genetic groups and spatial distribution, habitat, leaf morphology, size
structure, and flowering time of each genetic group were investigated on
Hahajima and the satellite Imoutojima Islands. Genetic groups were
identified using EST-SSR markers, revealing four ecotypes named based on
morphological features: Dwarf (D), Glabrescent (G), Tall (T), and Middle
(M), with M being a result of the hybridization of G and T. Ecotype D,
adapted to dry environments, is characterized by small tree size, dense
thick leaves with abundant hairs, and is distributed in dry scrub. Ecotype
G, adapted to understory of mesic forests, lacks leaf hairs. Ecotype T,
adapted to the canopy of mesic forests, has hairy leaves and is tall in
tree height. Ecotype M, adapted to the canopy of mesic scrub or edges of
mesic forests, has hairy leaves but with a shorter tree height than
ecotype T. Flowering peaks differed among all ecotype pairs except G and
M, but the flowering times more or less overlapped among all ecotypes,
suggesting that pre-mating isolation among ecotypes is not perfect.
Post-mating isolation is considered absent, as there were no differences
in the results, germination, and survival rates of one-year seedlings
among inter- and intra-ecotype crossings. The existence of such ecotypes
provides valuable insights into the ongoing speciation processes adapting
to the oceanic island environments.