RESUMO
We conducted a molecular phylogenetic analysis of a coastal sea lavender in NW Pacific using ITS sequences of nrDNA. As a result, the ITS sequences of populations on the oceanic Daito Islands were considerably different from conspecific others in nine apomorphic substitutions. This finding indicates a distance-independent geographical structure of the genetic variation among islands in NW Pacific. The calibrated rate of nucleotide substitutions in the ITS regions within L. wrightii (average: 1.41x10(-8) substitutions per site per year) was higher than any other instances of substitution rates in flowering plants.
Assuntos
Evolução Molecular , Genética Populacional , Filogenia , Plumbaginaceae/genética , DNA de Plantas/genética , DNA Espaçador Ribossômico/genética , Variação Genética , Geografia , Haplótipos , Funções Verossimilhança , Modelos Genéticos , Ilhas do Pacífico , Plumbaginaceae/classificação , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
Differentiation of flower colour is thought to be one of the most important factors promoting plant speciation. We describe the intraspecific variation of flower colour and its distribution in Limonium wrightii. We conducted a survey on 36 islands in the northwestern Pacific and discriminated six morphs of flower colour variation. Two flower colour morphs, pink and yellow, were most frequently observed, and their geographical distributions were basically allopatric. These two morphs were in contact in a narrow zone on Okinoerabu Island, located in the middle region of the Ryukyu Archipelago. In addition, orange, white, and ivory flower morphs were also found in this zone. The geographical distribution of pink and yellow morphs showed a "leapfrog" pattern; the distribution of pink flowers was divided into two areas, intercalated by the distribution of the yellow flower morph. The orange morph may have resulted from hybridization between the pink and yellow flower morphs.
