Little divergence in ribosomal DNA internal transcribed spacer ‐1 and ‐2 sequences among non‐digitate species of <i>Laminaria</i> (Phaeophyceae) from Hokkaido, Japan

Abstract

SUMMARY The nuclear ribosomal DNA internal transcribed spacer (ITS‐1 and ITS‐2) sequences were determined for 10 of 12 Japanese non‐digitate Laminaria species, Kjell‐maniella gyrata (Kjellman) Miyabe, Costaria costata (Turner) Saunders, Alaria praelonga Kjellman and Chorda filum (L.) Stackhouse collected at Hokkaido. Phyloge‐netic analyses (maximum parsimony and distance matrix) of these sequences, including published data for L. sac‐charina (L.) Lamouroux from Canada, showed strong nucleotide conservation among these species of Laminaria , but two phylogenetically distinct species groups were recognized. A L. japonica group encompassing L. yapon/ca Areschoug, L. religiosa Miyabe, L. ochotensis Miyabe, L. diabolica Miyabe, L. longipedalis Okamura, L. angustata Kjellman and L. longissima Miyabe; and a L. saccharina group including L. coriacea Miyabe, L. sac‐charina, L. cichorioides Miyabe and L. yendoana Miyabe. As to other laminarialean genera, Kjellmaniella gyrata was most closely related to the genus Laminaria , being related to the second Laminaria species group based on both parsimony and distant tree values.