Molecular evidence of the presence of Dictyota dichotoma in Argentina based on sequences from mtDNA and cpDNA and a discussion of its possible origin.

ALVES PEREIRA LOPES-FILHO E.; SALGUEIRO F. ; MATTOS NASCIMENTO S.; GAUNA, M.C.; PARODI, E.R.; CAMPOS DE PAULA J.

New Zealand Journal of Botany

RSNZ PUBLISHING

Lugar: Auckland; Año: 2017

0028-825X

Dictyota is a brown alga genus inhabiting tropical to warm temperate environments where it 15 performs an important ecological role, such as a food source, shelter and substrate to several 16 species of invertebrates and other algae. The taxonomy of this genus is troublesome, with poor 17 species delimitation and doubtful records in the literature. Dictyota dichotoma, the type species 18 of the genus, was commonly accepted as a cosmopolitan species because of the inaccurate 19 geographical distribution range as a consequence of its misidentification in several parts of the 20 world. Recent studies with molecular data revealed new species and a new understanding of the 21 evolution and biogeography of the genus Dictyota. These studies confined populations of D.22 dichotoma to Europe (Atlantic and Mediterranean coasts) and the Macaronesian Islands (Azores,23 Madeira and Canary archipelagos). Also, they confirmed its presence in South Africa, but, 24 whether the species was native or introduced in South Africa could not be verified. In the present 25 study two regions of cpDNA (psbA, rbcL) and one region of mtDNA (nad1) from Argentine 26 samples, identified morphologically as D. dichotoma, were analyzed and compared with other 27 Dictyota species. The identity of these samples as D. dichotoma was confirmed. A haplotype 28 network analysis using all available psbA sequences distinguished seven haplotypes divided into 29 two geographic groups: Atlantic-Mediterranean and Canarian. In Argentina and South Africa, only 30 the most common haplotype of the Atlantic?Mediterranean group was observed. According to the 31 paleoceanographic currents and the presence of European haplotype, the introduced nature of D. dichotoma is indicated.