Background: Bulung sangu (Gracilaria sp). is wildly widespread Rhodophyta in Bali and usually consumed as vegetable. Bulung sangu is reported for its bioactive compound scientifically proven as antioxidant, anti-inflammatory, and anti-hypercholesterolemia. Likewise, Bulung sangu as Rhodophyta is a potential source for food, fertilizer, cosmetic and pharmaceutical industry. Bulung sangu production is highly fluctuating and unable to meet its demands. Proper and correct cultivation methods based on molecular information are expected to increase the availability of Bulung sangu in Bali. Complete taxonomy is required to design the proper cultivation method. Meanwhile, Bulung sangu taxonomy is limited to the genus level. More information on Bulung sangu strain is needed, either does its relatedness.
Methods: Fresh Bulung sangu was collected from Serangan coastal area, Bali. DNA extraction was applied followed by PCR amplification using six combinations of COI primer sequence. DNA sequences obtained was evaluated to determine pairwise distance, percent of similarity and phylogenetic relationship compared to Gracilaria species registered in GenBank.
Results: PCR amplification produced 730 base pairs amplicons. Genetic distance and percentage of similarity obtained exhibit relatedness to Gracilaria gracilis with 0.487 of pairwise distance and 49.04% of similarity. The phylogenetic tree produced seven clades in which Bulung sangu and Gracilaria gracilis were in the same clade.
Conclusion: Bulung sangu showed closest relatedness to Gracilaria gracilis.