Phylogeny and genetic variation in the genus Eranthis using nrITS and cpIS single nucleotide polymorphisms

Abstract

The relationships among species in the genus Eranthis Salisb. were investigated using single nucleotide polymorphisms (SNPs) of the nuclear DNA internal transcribed spacer 1, 2 region (nrITS) and the chloroplast trnL-trnF interspacer region (cpIS). Phylogenetic relationships based on the nrITS and cpIS were inferred with posterior probabilities with STRUCTURE analysis and the neighbor-joining method. Two major clades from nrITS and cpIS were consistent with species with yellow sepals in E. hyemalis, E. cilicica, E. longistipitata and the hybrid E.xtubergenii; and white sepals in E. sibirica, E. longituba, E. albiflora, E. stellata, E. pungdoensis, E. byunsanensis, and E. pinnatifida. The phylogenetic tree of nrITS formed more subclades than the tree of cpIS, which suggested that nrITS SNPs are useful molecular markers for phylogenetic studies in the genus Eranthis. Only the SNPs of cpIS in E. pungdoensis accessions had a deletion at positions 259-420, and the posterior probability values (PPVs) assigned E. pungdoensis to population 4, which suggested that E. pungdoensis is different from E. byunsanensis. Therefore, E. byunsanensis and E. pungdoensis are considered to be true-to-type based on q-values because the PPVs were greater than 0.9 in both species based on the STRUCTURE analysis of nrITS SNPs. Significant genetic variation in E. stellata collected in Goesan-kun and Mt. Mugap, Korea indicated a potential gene flow among closely related E. byunsanensis, E. pinnatifida, E. sibirica, and E. stellata that could be due to geographic proximity in their distributions. E. stellata from Mt. Mugap showed mixed PPVs for E. stellata and E. byunsanensis, therefore, E. byunsanensis might be a possible hybrid origin for E. stellata collected from Goesan-kun and Mt. Mugap.