title: Morphological and molecular variation in Mitchella undulata, with special reference to the systematic treatment of the dwarf form from Yakushima.
abstract: Morphological and molecular variation in Mitchella undulata Siebold et Zucc. was examined to evaluate the genetic basis for recognizing the dwarf variety, M. undulata var. minor Masamune. Considerable variation in leaf size in M. undulata, but no obvious morphological discontinuities, were found between the normal and dwarf varieties. Instead, a weak cline running from the Pacific Ocean to the Sea of Japan was found. Anatomical observations of leaf blades revealed that the large variation in leaf size can be attributed to variation in the number of leaf cells and not to differences in cell size. A molecular analysis based on sequences of rDNA internal transcribed spacer regions indicated that there were two major genotypes in M. undulata with minor variation in haplotypes resulting from additional substitutions or putative recombination. The dwarf form from Yakushima was neither genetically uniform nor apparently differentiated from other populations. From these results, we conclude that the dwarf form of M. undulata should be treated at the rank of forma.
authors.affiliation: Department of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fukuda
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tsukaya
mesh_terms: D001483:Base Sequence; D002467:Cell Nucleus / Q000235:genetics; D018744:DNA, Plant; D004275:DNA, Ribosomal; D014644:Genetic Variation; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology; D019666:Rubiaceae / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D018744:DNA, Plant; D004275:DNA, Ribosomal