Molecular Assessment of Kappaphycus alvarezii Cultivated in Tarakan based on cox2-3 Spacer

The seaweed Kappaphycus alvarezii is a leading aquaculture commodity possessing high economic value that has been used as a raw material for various natural products, food, and pharmaceutical industries. The main challenge regarding its production, escpecially in Tarakan is the supply of superior seeds. Therefore, this study aims to obtain phylogenetic information and the cultivation performance of the selected seeds by identifying genetic sources based on molecular markers. DNA sequencing analysis was carried out using the molecular marker cox2-3 spacer on a collection comprising 16 cultivars from all over the country (Indonesia). The four haplotypes representing K. alvarezii to be cultivated in the city were produced by phylogenetic clustering and further molecular analysis using cox2-3 intergenic spacer mitochondrial DNA marker. These include the Kupang varieties and Natuna, also referred to as Lampung seedlings, which is a tissue culture plantlet used for development at SEAMEO-BIOTROP Bogor and propagated by the Lampung Marine Aquaculture Center (BBPBL), Tarakan. These varieties were genetically distances (pairwise comparisons based on mean Kimura 2-parameter model) ranging from 0.00-0.23 unit. The cultivation was carried out for 30 days in the waters of Tanjung Batu (Tj. Batu) Mamburungan, Tarakan, North Kalimantan, for 30 days. The result showed that the Natuna* as Lampung cultivar has superior performance compared to local cultivars (Takalar as Mamburungan Tanjung Batu, Tarakan, and Kupang). Furthermore, the genetic analysis with cox2-3 spacer markers had the potential as an effective seed selection tool for tracing genetic information in the development of superior seedlings in aquaculture activities.