Population genetic structure and diversity of a critically endangared Ramin [Gonystylus bancanus Miq.(Kurz), Thymelaeaceae] from Kalimantan and Sumatra based on Sequence Random Amplified Polymorphism

Abstract

Gonystylus bancanus (Miq.) Kurz (Thymelaceae) or ramin is an important species producing valuable timber. The existence of this species has now under severe threat due to illegal logging and habitat conversion. Ramin is found only on peat swamp forests, scatteredly distributed in Peninsular Malaysia, Sumatra, and Borneo. Genetic diversity of ramin in the Malesian region has been studied previously for Sumatran populations as well as East and West of Malaysian populations. This present study aimed to determine the genetic diversity and population structures of ramin from Sumatra and Kalimantan using Sequence Random Amplified Polymorphism (SRAP). Five combinations of SRAP primers used to amplify seventy seven samples of ramin from eight populations. Eighty-three putative loci of SRAP were scored and analysed using Popgene and MVSP software. Among eight populations studied, NPL were ranged between 14 – 68 with PPL varied at 16.87 – 81.93%. Number of observed alleles and effective allele numbers were ranged between 1.17 – 1.76 and 1.13 – 1.36 respectively. The lowest gene diversity was accounted for population 2 (He = 0.08) while the highest gene diversity was population 7 and 8 (He = 0.22). The Sumatran and Kalimantan populations were genetically structured at medium level (Gst = 0.25). The pairwise genetic distance among Sumatran and Kalimantan population was considered low (0.04-0.07), and is between Sumatran populations (0.01 – 0.17). The results from this study can be used as an essential information to design conservation strategy for ramin in Indonesia.