Identification, Genetic Diversity and Phylogenetics of Germplasm using COX1 Marker: Preliminary Study for New Tilapia Breeding Scheme

This study aims to analyze the genetic biodiversity of domesticated tilapia (kekar, sultana, DSLU) and wild tilapia (WPLU) in the context of the tilapia breeding program in South Sulawesi, Indonesia. Kekar and sultana tilapia strains were tilapia broodstock from Java Island introduced to South Sulawesi in 2022, while DSLU and WPLU tilapia strains are tilapia from Salulemo hatchery and wild tilapia caught in Poreang Creek in North Luwu, South Sulawesi, respectively. The other four Kekar are the first generation of Kekar from the broodstock introduced from Java to South Sulawesi (22PFG1). The alignment of 656 bp mt-DNA COX1 sequences showed that specimens originally thought to be Oreochromis niloticus were identified as O. niloticus and O. mossambicus, while the WPLU strain was identified as O. aureus. The 64 single nucleotide polymorphisms (SNPs) identified resulted in seven haplotypes that formed four clades. Tilapia strains were spread across four clades, indicating that tilapia has high genetic diversity. Salulemo tilapia had a genealogical relationship with sultana and kekar O. niloticus strains. These results suggest that tilapia introductions have included O. mossambicus and O. niloticus. The wild O. aureus in Poreang Creek, North Luwu, is a first record for O. aureus in Indonesia. The discovery of O. aureus is useful for designing tilapia breeding programs to produce all-male seeds.