RNA-seq of Rhododendron species

Loss of genetic diversity increases the extinction risk of a population through inbreeding depression. In addition to that, the amount of deleterious genetic variations, which might be accumulated in a small population through genetic drift will make the population vulnerable. We compared the amounts of genetic diversity and deleterious genetic variations between critically endangered azalea species, Rhododendron boninense, whose population size in the wild was only one, growing in the Bonin islands, a UNESCO World Heritage and congeners. Based on the information from RNA-seq, the amount of deleterious variation of R. boninense was significantly larger than that of R. amanoi. The accumulated deleterious variation of R. boninense might result in vulnerability of the species.