Molecular Phylogeny of the Lady Fern Genus Athyrium in Japan Based on Chloroplast rbcL and trnL-trnF Sequences

Abstract

Phylogenetic relationships in Athyrium and Cornopteris were deduced from two chloroplast DNA fragments, rbcL and trnL 5´exon–trnF, of 32 species, 2 varieties, 3 putative hybrids of Athyrium, three taxa of Cornopteris, and five outgroups. Athyrium is paraphyletic, and the Athyrium– Cornopteris complex comprises five clades. Clade I, the most basal, comprises A. niponicum, A. (= Anisocampium) sheareri, and A. (= Kuniwatsukia) cuspidatum. Clade II includes A. distentifolium and Cornopteris. All species of clades III and IV are diploids, while most species of clade V are polyploids. The parentage of the putative hybrids and of species of hybrid origin were also suggested. The results were compared to previous major classifications based on morphology.