Identifikasi Molekuler dan Keragaman Genetik Rumput Laut Turbinaria sp. dengan Gen Kloroplas rbcL di Perairan Tapanuli Tengah

Abstract

Seaweed from the genus Turbinaria is a brown macroalga that has significant economic value and ecological roles in tropical waters. However, morphological variations influenced by environmental conditions often lead to difficulties in accurately identifying species. This study aims to identify Turbinaria species morphologically and molecularly, as well as to analyze its genetic diversity in the waters of Tapanuli Tengah, North Sumatra. Nine Turbinaria samples were collected from three locations: Batu Gajah, Pandaratan, and Pulau Pane. Morphological identification was conducted based on thallus structure, phylloid, and receptacular branching. Furthermore, molecular identification was performed using DNA Barcoding methods with the chloroplast rbcL gene through PCR techniques, sequencing, BLAST analysis and phylogenetic analysis using MEGA 11 software. The results show that two species were identified: Turbinaria ornata and Turbinaria decurrens. BLAST analysis showed a percentage identity of 98–100% and a query cover of 96–99%. The phylogenetic tree using the Neighbor-Joining method grouped the samples according to their species, while the genetic distance between specimens showed values ranging from the lowest 0.000 to the highest 1.059. This study emphasizes the importance of molecular approaches in the identification and management of Turbinaria seaweed diversity, as well as serving as a basis for conservation and sustainable utilization in the coastal areas of Central Tapanuli.