Abstract
Arabidopsis thaliana (Brassicaceae) and its closely related species serve as model systems for evolutionary studies. Although much information about the genome of the species of Arabidopsis has been collected, knowing the genomic structure of targeted systems is required for determining which genes are involved in adaptation to particular environments. In this study using amplified fragment length polymorphisms (AFLP), we determined the genomic structure of A. halleri subsp. gemmifera (Brassicaceae) on Mt. Ibuki, Japan, where two ecotypes adapted to lowland and highland environments grow. Based on 273 loci (4.4% of the loci were outliers), genotypes of 17 and 14 individuals of lowland and highland ecotypes, respectively, were determined. When excluding outliers, genetic differentiation between the two ecotypes was low (F_<ST>=0.017). The genotypes of each ecotype, however, were distinguishable using principle coordinate analysis. The genome-wide investigation of the two ecotypes of A. halleri subsp. gemmifera on Mt. Ibuki therefore suggests that morphological divergence as well as adaptation to local environments between lowland and highland ecotypes occurred recently and the two ecotypes share a similar genomic structure. These two ecotypes are therefore appropriate for studies to reveal the genetic basis of morphological divergence as well as local adaptation using genomic information from A. thaliana.
