Background:The Philippines is home to some ethnomedicinal Apocynaceae that has been used to cure common ailments. They are perceived to be safe, but misidentification can lead to substitution and adulteration. Morphological characters are primarily utilized to identify these species but a new method utilizing molecular characters called DNA barcoding has emerged. In this study, the efficiency of matK, rbcL, trnH-psbA, and trnL-F to molecularly authenticate selected Apocynaceae species were tested.Materials and Methods:Genomic DNA from silica-dried leaf samples were isolated and used as a template for generating DNA barcodes. Pair-wise sequence divergence using Kimura-2-Parameter was used to analyze inter-specific and intraspecific variations among the barcodes, whereas basic local alignment search tool (BLAST) and neighbor-joining (NJ) analyses were employed to examine discrimination success.Results:The results show that matK is the best barcode for Apocynaceae as it has the highest amplification and sequencing success together with rbcL while having high inter-specific and low intra-specific divergence relative to the other candidate barcodes. Furthermore, matK provided the highest discrimination both in BLAST and NJ analyses.Conclusion:This study proposes the use of matK as the principal barcode for Apocynaceae.SUMMARY Both matK and rbcL have higher universality compared to trnH-psbA and trnL-FmatK has relatively high inter-specific divergence and very minimal intra-specific divergencematK is the best barcode to molecularly authenticate Apocynaceae with either trnH-psbA or trnL-F as supplements. Abbreviations used: K2P: Kimura-2-parameter, BLAST: Basic local alignment search tool, NJ: Neighbor-joining.

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The little known endemic Philippine Rubiaceae Adenosacme apoensis Elmer was transferred to the genus Mycetia Reinw. based on herbarium specimens. Also, Mycetia apoensis was once thought as conspecific with M. cauliflora. To date, M. apoensis lacks comprehensive vegetative and reproductive descriptions to fully understand the species and be able to delineate from other members of Mycetia. To verify the generic affiliation of the species with more certitude, two chloroplast markers (rps16 intron and trnL-F region) were sequenced from the recent collections at Mt. Apo, Davao. Bayesian analysis of the combined plastid (rps16 and trnL-F) dataset strongly supported (PP = 1.0) the inclusion of M. apoensis in the genus Mycetia and resolved M. cauliflora as its sister-taxa. A comprehensive description and botanical illustrations of M. apoensis as well as its conservation status based on IUCN criteria are here provided.