Adil GÜNER, Vehbi ESER - optima

Posters
MOLECULAR TEST OF CURRENT TAXONOMIC CLASSIFICATION
AND EVOLUTIONARY PROCESSES IN THYMUS SECT. MASTICHINA
(MILLER) BENTHAM
174
V. GIRÓN 1 , B. VALDÉS 1 , R. PARRA 1 & E. PÉREZ-COLLAZOS 2
1 Universidad de Sevilla, Facultad de Biología, Dpto de Biología Vegetal y Ecología, Sevilla, Spain
vgiron@us.esm
2 Universidad de Zaragoza, Escuela Politécnica Superior de Huesca, Dpto. de Agricultura y Economía
Agraria, Huesca, Spain; ,
Thymus L. sect. Mastichina (Lamiaceae Juss.) is endemic to the Iberian Peninsula and
includes three taxa: T. albicans Hoffmanns. & Link (2n = 30), T. mastichina (L.) subsp.
mastichina (2n = 60) and T. mastichina subsp. donyanae Morales (2n = 30). The high
similarity of their morphological characters has led to controversy on their taxonomic position
and geographical distribution of this group.
This study has tested the current taxonomic classification from a molecular perspective, in
order to infer the evolutionary processes that may have modelled the section. Two-hundred
thirty-two individuals, collected over the entire distribution of the taxa were assayed with the
AFLP technique.
The AMOVAS, NJ, PCO and MST of the genetic data were consistent with the currently
recognized taxa, and gave genetic support to the taxonomic classification proposed by
Morales (1986). Furthermore, high levels of genetic diversity also revealed the welfare of the
section, even in the case of the threatened T.albicans.
In an evolutionary context it is likely that T. albicans may have had an older and wider
distribution, followed by a recent habitat fragmentation, and might have originated the other
two taxa by two independent evolutionary events. Thus, T. mastichina subsp. mastichina
might have been originated by polyploidization and subsequent radiation to central and
northern areas of the Iberian Peninsula, while T. mastichina subsp. donyanae might have been
originated by geographic isolation after the recent formation of the Doñana area.
Keywords: Thymus sect. Mastichina, AFLP, taxonomy, evolutionary processes.
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