The genetic diversity of angsana (Pterocarpus indicus) in Purwodadi Botanical Garden Indonesia revealed by rDNA ITS

Abstract

Pterocarpus indicus or angsana is one of the tropical tree species that produce redwood. It has been listed as an endangered species by IUCN since 2018, as its natural population number has declined and possibly extinct in some countries. Therefore, conservation efforts to protect this species must be carried out based on the appropriate conservation strategy. This study aimed to assess molecular characters of Pterocarpus species in Purwodadi Botanical Garden using rDNA ITS (internal transcribed spacer) and its association with morphological characters. Information on genetic and morphological characters will precisely identify this species so that conservation strategy can be appropriately planned. Leaf samples of eighteen P. indicus trees were collected from Purwodadi Botanical Garden (PBG) and used in this study. Twelve specimens that provide clear DNA sequence were genetically assessed. The results showed that P. echinatus exhibited rDNA ITS character similar to that P. indicus, while P. indicus specimens from Morotai were very different from other P. indicus specimens. Morotai specimens showed 89% similarity to several Pterocarpus species, including P. acapulcensis, P. rohrii and P. indicus. The morphological characters were assessed along with molecular characters. The impacts of conservation strategies are discussed in this paper.