4th Annual WML Academic Symposium

Nototrichium (Amaranthaceae) is a genus containing three species of shrubs to small trees that are endemic to the main Hawaiian Islands. We conducted a phylogenetic study of the genus to elucidate its origins and interisland biogeography. DNA from all species of Nototrichium, including N. sandwicense from each island, was extracted from field and herbarium specimens. DNA was also extracted from several Pacific representatives of the closely related genus Achyranthes. Extracted materials were sequenced and aligned for the Internal Transcribed Spacer (ITS) region. Additionally we investigated four other gene regions including petL-psbE, rps16-trnK, rpl32-trnL and G3PDH for inclusion in the phylogeny. Our analyses using Maximum Parsimony Analysis showed that Nototrichium is monophyletic, however, N. sandwicense is paraphyletic. There appears to be a geographic correlation to the distribution of two clades within the genus. A more specious clade is associated with the older, western islands of Kauai and Oahu whereas a less specious clade is associated with the younger, eastern islands of Molokai, Lanai, Maui and Hawaii. Our analyses of the relationship between Nototrichium and Achyranthes confirm our earlier findings of an Asian origin of Nototrichium. Of the additional tested chloroplast regions, rpl32-trnL sequenced well and will be incorporated into future phylogenies of the genus. In the future, we plan to investigate additional nuclear and chloroplast gene regions in order to assemble a more robust phylogeny of Nototrichium.