A genetic investigation of two morphotypes of Palmaria palmata (Palmariales, Rhodophyceae) using Rubisco spacer and ITS 1 and ITS 2 sequences

Stefan KRAAN & Michael D. GUIRY

en Cryptogamie, Algologie 27 (1) - Pages 17-30

Published on 24 February 2006

Numerous varieties and formae have been described of Palmaria palmata (Linnaeus) O. Kuntze (Palmariales, Rhodophyceae), which is essentially a morphologically plastic entity. The most striking of these is the sarniensis-sobolifera varietal complex. Four isolates of this complex and nine of the type variety were genetically compared using plastid-encoded Rubisco spacer sequences and the Internal Transcribed Spacer (ITS 1 and 2) sequences of the nuclear ribosomal cistron. Analysis of the Rubisco spacer sequences resulted in one phylogenetically informative site (excluding the out-group). Phylogenies inferred from the ITS 1 and 2 showed the European isolates separating from a single east Canadian isolate, but did not resolve monophyly of any of the two morphotypes. The average of the Jukes-Cantor distances fell within the range found for conspecific samples of other palmarialean algae and, therefore, we conclude that the type and entities from the sarniensis-sobolifera complex are phylogenetically indistinguishable with respect to the DNA examined. We therefore propose that the use of a varietal designation for the sarniensis-sobolifera and palmata complex be discontinued.

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