Phylogenetic analysis of Pterocarpus indicus Willd. accessions in Mt. Makiling, Laguna, Philippines based on its, matk and rbcL barcodes

This research aimed to analyze the phylogenetic relationships among Pterocarpus indicus Wild. accessions in Mt. Makiling Forest Reserve (MMFR), Laguna, Philippines nased on ITS, MatK and rbcL, respectively. The sequences were edited in Geneious Prime and aligned in MEGA X. Phylogenetic trees were constructed in MEGA X with a bootsrap value of 1000. The multiple sequence alignment showed that ITS1 gene had the highest variation among Narra samples (90.29% similarity), followed by ITS2 (98.8% similarity). The matK gene showed the highest similarity (100%) among Narra samples, followed by rbcL (99.8%). The multiple sequence alignment of ITS2 gene differentiated the smooth Narra (SN) from the prickly Narra (PN) with the two SN sample having cytosine at position 111 and PN samples with thymine. Phylogenetic analysus of ITS2 barcode. The ITS1 barcode dod not differentiate the SN from the PN. The phylogenetic analysis of Narra samples from the MMFR and those from other countries showed that some Narra samples are more closely related with those from other countries instead of those from MMFR. Two (MP-002 and TAM-001) of the seven samples from MMFR formed the outer-most branch of the phylogenetic tree constructed based on the concatenated ITS barcode. The phylogenetic tree constructed based on matK showed that one (ARBOR-002) of six samples from MMFR clustered with samples from other countries in clade A while the other two formed clade B. The variations observed in Narra samples based on the molecular barcodes used indicate that adaptive genetic variations of Narra exist. Identifying and monitoring these genetic variants can have direct utility for conserving species at risk such as Narra. In addition, this study is the first to report the molecular variation between the two forms of Pterocarpus indicus recognized in the Philippines, Pterocarpus indicus forma echinatus (Prickly Narra)and Pterocarpus indicus forma indicus (Smooth Narra).