2018 ASHS Annual Conference

The genus Plumeria L. is a member of the family Apocynaceae that is valued in many parts of the world for religious, ornamental, ethnobotanical and cosmetic purposes. However, the taxonomy of Plumeria species (spp.) is not well-understood, which has huge implications in the realms of bioprospecting and plant breeding. Identification of a spp. can be achieved through morphological and molecular means, but phenotypic plasticity may hinder accurate identification of a spp. and molecular markers must be tested prior to commercializing their use. Thus, a combined approach using morphological and molecular markers will help to identify Plumeria spp. and determine genetic relationships within this genus. The objectives of this research are to 1) identify a combination of morphological markers that will distinguish among Plumeria spp., and 2) identify molecular markers will also identify Plumeria spp. Seventy-five samples of 13 putative Plumeria spp. were collected from germplasms of Hawaii and Florida, and analyzed for the presence or absence of 52 morphological characters, in addition to evaluating five DNA barcodes (partial matK, psbJ-petA, rpl32-trnL, trnH-psbA, and ITS2). Based on three principal components of the morphological data, only five groups were identified out of the 13 putative spp. No single DNA barcode was able to distinguish any more than four spp. Even the combination of all five DNA barcodes was insufficient to identify more than 40% of putative Plumeria spp. tested. It is thus recommended to identify other morphological characters and molecular regions to accurately identify Plumeria spp.