A study on the intraspecies structure of Scytosiphon lomentaria (Phaeophyceae)

花管藻是世界上寒温带海岸常见的一种褐色藻类。在日本，在nrDNA的ITS区和线粒体cox3基因中发现了一些遗传多样性。本研究的目的是界定在这种形态的物种，使用ITS2和cox3单倍型的组合，是独立遗传的，并进行杂交实验，以评估的单倍型分析所建议的界定的隐种。对来自日本各地的90个样本进行了检查，在ITS 2中发现了26个单倍型，在cox 3中发现了31个单倍型。系统发育分析结果表明，ITS 2有8个单倍型群，cox 3有11个单倍型群。ITS2和cox3之间的单倍型组合表明存在3个隐种。使用14只雌性和11只雄性的培养菌株进行杂交实验。杂交试验的结果表明，三个育种群体。这三个育种群体对应于由单倍型群体的组合所建议的隐种。本研究表明，独立遗传的单倍型组合的分析是有用的界定的隐种。

Scytosiphon lomentaria is a common brown alga in the cold and temperate coasts of the world. In Japan, some genetic diversity have been found in the ITS regions of nrDNA and the mitochondrial cox3 gene. The aim of this study is to delimit the cryptic species in this morphological species, using combinations of ITS2 and cox3 haplotypes that are independently inherited, and to conduct crossing experiments in order to evaluate the delimitation of the cryptic species that was suggested by the haplotype analyses. 90 samples from various localities in Japan were examined, and 26 haplotypes were found in ITS2, and 31 haplotypes in cox3. Results of phylogenetic analyses suggested 8 haplotype groups in ITS2 and 11 haplotype groups in cox3. The combinations of the haplotype groups between ITS2 and cox3 suggested the existence of three cryptic species. Crossing experiments were conducted using cultured isolates of 14 females and 11 males. Results of the crossing experiments suggested three breeding groups. The three breeding groups corresponded to the cryptic species that were suggested by the combinations of the haplotype groups. The present study demonstrated that the analyses of combinations of independently inherited haplotypes are useful for delimitation of cryptic species.