title: Evaluation of morphological and molecular variation in Plantago asiatica var. densiuscula, with special reference to the systematic treatment of Plantago asiatica var. yakusimensis.
abstract: Morphological and molecular variations in Plantago asiatica L. var. densiuscula Pilg. were analyzed to evaluate the genetic basis for recognizing the dwarf variety P. asiatica var. yakusimensis (Masam.) Ohwi. Considerable variation in the leaf size of P. asiatica var. densiuscula was observed, and no morphological discontinuities were found between the dwarf types of P. asiatica var. densiuscula and P. asiatica var. yakusimensis. Morphological analysis of plants grown under standardized conditions revealed that both environmental plasticity and genetic differentiation contributed to the dwarfisms. Molecular phylogenetic analysis of rDNA internal transcribed spacer (ITS) regions and the SUC1 locus encoding a sucrose transporter revealed that P. asiatica var. yakusimensis was genetically unique although the differentiation level was low. From the above results, we concluded that P. asiatica var. yakusimensis should be reduced to a form of P. asiatica var. densiuscula. Furthermore, the geographic distribution of the SUC1 genotype suggested multiple origins of dwarves, and possible hypotheses for the origins of dwarves are discussed.
authors.affiliation: National Institute for Basic Biology/Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8585, Japan. nakoo@nibb.ac.jp
authors.forename: Naoko
authors.initials: N
authors.lastname: Ishikawa
authors.forename: Jun
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikeda
authors.forename: Eriko
authors.initials: E
authors.lastname: Takabe
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tsukaya
mesh_terms: D001483:Base Sequence; D021901:DNA, Intergenic / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D017753:Ecosystem; D014644:Genetic Variation; D026901:Membrane Transport Proteins / Q000235:genetics; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology; D010940:Plant Proteins / Q000235:genetics; D010943:Plantago / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics / Q000502:physiology*; D011003:Ploidies; D012639:Seeds; D013624:Taiwan
chemical_list: D021901:DNA, Intergenic; D018744:DNA, Plant; D026901:Membrane Transport Proteins; D010940:Plant Proteins; C078729:sucrose transport protein, plant