Preliminary insights into the molecular barcoding data of Turraea socotrana (Meliaceae) from Socotra (Yemen)

Abstract

The relationship of two geographically and ecologically separated populations of Turraea socotrana Styles and F. White (Meliaceae), a vulnerable and scattered shrub from the island of Socotra (Yemen), was explored using preliminary molecular data. The nuclear ribosomal ITS region was used to screen the level of genetic divergence of T. socotrana from ecologically distant localities in comparison to a few other species of Turraea and closely related genera. The individuals from the inland (Diksam) differed from the western coastal ones (Ma’alah) by vegetative characters and by the rbcL gene. This may be due to the fact that the population from Ma’alah grows on lithosoil slopes directly exposed to moist winds coming from the sea, whereas the population of Diksam occurs on arid cliffs overlooking the inland of the island. The ITS sequences grouped the studied populations from Socotra together and separated them from other species of Turraea that are morphologically similar and occurring in East Africa. Considering the differences recorded in the rbcL gene, we suggest that the populations of T. socotrana investigated here on only a few specimens from two different areas on the island, deserve more research. Our preliminary study potentially indicates that there may be independent evolutionary significant units in this species, however, more research including a wider sampling and comparison to other taxa is needed.