Identifikasi Molekuler dan Keragaman Genetik Rumput Laut Sargassum sp. di Perairan Tapanuli Tengah

Abstract

Seaweed is one of Indonesia's leading commodities with high economic value and ecological benefits. Sargassum sp., as part of the brown algae group, is widely found in Indonesian waters, including in Tapanuli Tengah Waters. However, the identification of Sargassum species in this region is generally still limited morphologically. This study aims to identify Sargassum species molecularly and determine their genetic diversity through phylogenetic analysis. Samples were collected from three locations namely Pane Island, Pandaratan Beach, and Batu Gajah Beach. Identification was carried out using DNA barcoding method with ITS2 marker and bioinformatics analysis through BLAST and MEGA XI software. The identification results showed that all samples belonged to the Sargassum polycystum species. Although only one species was found, phylogenetic analysis showed haplotype differences between samples, which were reflected in the genetic distance values and branches on the phylogenetic tree. This finding indicates the existence of intraspecific genetic variation in Sargassum polycystum populations in the region. This research is expected to enrich the molecular information of seaweed in Indonesia and become the basis for utilization of marine biological resources.