Genomic insights into diversification and ecological speciation of three Saccharina species

Aim: Saccharina is a genus within the brown algae that is of ecological and economic importance and shows rapid adaptive radiation, while the process and genetic mechanism of diversification and speciation remains unclear. In this study, we conducted genome resequencing of three typical Saccharina species, including the four varieties of S. japonica, and its two sister species (S. angustata and S. longissima) to investigate the genetic mechanism of ecological speciation.
Location: coast of Japan
Methods: We assess the genomic differentiation and genetic diversity of these Saccharina kelps based on whole-genome resequencing. We applied composite-likelihood approach to identify the ancestral species and reconstruct the evolutionary history. Selective sweep analysis was conducted to detect selective signatures when they adapted to diverse habitat.
Results: The demography suggested that S. angustata, S. longissima and S. japonica var. japonica underwent adaptive speciation early, with S. ja...