Molecular identification of the brown algae, Cystoseira spp. (Phaeophycae, Fucales) from the Adriatic Sea – preliminary results

Abstract

           In the attempt to identify an appropriate molecular marker which will enable genetic distinction between different Cystoseira species from the Adriatic Sea, two mitochondrial molecular markers were tested: the mt 23S rDNA and the mt23S-tRNAVal spacer. Two species were studied: Cystoseira spinosa and Cystoseira squarrosa. Sequence analyses showed no variation in the mt 23S rDNA among all individuals analyzed. But the analysis of the mt23S-tRNAVal spacer showed a differentiation between three haplotypes named A, B and C. The most abundant haplotype A was found in equal number in both species, while haplotype B was found only in C. spinosa and haplotype C was found only in C. squarrosa. However, when comparing to sequences available for several selected Mediterranean Cystoseira species, the mt23S-tRNAVal spacer failed to discriminate between species. Although these results indicate a limited use of the mitochondrial mt23S-tRNAVal intergenic spacer for discrimination among Adriatic Cystoseira species, they could also be interpreted as a sign of conspecificity of the investigated species or the reflection of a recent radiation. Further analysis will be necessary to improve molecular identification of these brown algae.