The genus Uncaria (Rubiaceae) is a group of widespread woody plants with optimum diversity. Indonesia has over 103 cultivars of gambir and its wild relatives; however, research on wild Uncaria, particularly in West Sumatra, Indonesia, remains limited. The related study aimed to analyze the phylogenetic relationship of Uncaria spp. in West Sumatra, Indonesia, and recognize the speciation processes in U. gambir as an important germplasm. In this study, the collection of 16 gambir samples came from Pesisir Selatan (Siguntur and Taratak Tempatih) and Lima Puluh Kota (Simpang Kapuak and Ampalu), with 12 samples sequenced using data from the GenBank. Extracting DNA used the CTAB method, amplified with ITS markers, and sequenced. Carrying out the analysis engaged the Bioedit application for alignment and MEGA for phylogenetic reconstruction and genetic distance. The ITS sequence was 623 bp long with a GC content of 61.5%. U. gambir forms a monophyletic clade, found closely associated with the species U. yunnanensis and U. lanosa. The genetic distance (0.099–0.102) between U. gambir and other species was greater than between its own species (0.000–0.003). These results will support the domestication and selection of U. gambir for sustainable breeding and future conservation.
Uncaria spp., wild relatives, cultivated species, domestication, ITS, phylogenetic analysis, genetic distance, germplasm conservation, West Sumatra
Uncaria gambir constitutes a remarkably homogeneous genetic group characterized by the least intraspecific variation. Its close relationship with the species U. yunnanensis and U. lanosa revealed an evolutionary connection and possible ancestral origin in East Asia. The results support sustainable breeding efforts and future conservation of Uncaria germplasm.