5 CONCLUSIONS
Our investigation revealed three well supported genetic clades in the
Hainan island endemic plant P. heterotricha , and proposed
hypotheses to construe the phylogeographic patterns detected (Figure 2
and 3). The genetic results highlight for the first time the critical
role of riverine isolation caused by the Changhua and Wanglou Rivers in
the patterns of intraspecific evolution of plant populations on Hainan
Island. However, such barrier effects for the speciation mechanism of
this island-endemic herb and other similar plants are still in need of
further illumination, especially by reproductive studies, and enhanced
mainland sampling. Both are important to construe the origins of the
speciesʼ high current genetic diversity.
Importantly, the three groups of populations detected are genetically
quite distinct, which calls for their independent management in any
conservation strategy, in order to avoid disrupting their current
genetic structure and their prospects of future evolution.