Genetic diversity of threatened aquilaria sp. In Malaysia using inter simple sequence repeat (ISSR) markers

Abstract

Background and Objective: Aquilaria sp. (family Thymelaeaceae) or commonly known as gaharu, karas or agarwood is one of the threatened crops that have been listed in the Convention on International Trade in Endangered Species (CITES). Overexploitation in search of valuable agarwood or resinous wood has directly led to scarcity of Aquilaria sp. in the wild. The aim of this study was to investigate the genetic diversity among three Aquilaria sp. (A. malaccensis Lam., A. subintegra Ding Hou and A. sinensis (Lour.) Spreng.) using inter simple sequence repeat (ISSR) markers. Materials and Methods: Five annealing temperatures varying from 47-51∘C were optimized. Out of 10 ISSR primers screened, 4 primers revealed clear and repeatable bands. Results: The clearest bands were observed at 50∘C, which was later used for primer screening and PCR amplifications. The 4 primers (UBC 855, UBC 845, UBC 811 and UBC 809) yielded a total of 23 bands, of which 20 were polymorphic (87%). The UBC 809 and 845 showed 100% polymorphism with a total of 6 and 4 bands, respectively. The UBC 855 showed 6 polymorphic bands (75%) and UBC 811 showed 4 polymorphic bands (80%). Construction of UPGMA dendrogram has grouped all the 15 accessions of 3 Aquilaria sp. into 2 major clusters, where all A. malaccensis accessions were grouped into cluster I and a combination of A. sinensis and A. subintegra accessions were grouped into cluster II. Conclusion: Findings of this study provide basic information for conservation and utilization of the Aquilaria genetic resources.