Article

The species of Primula L. sect. Auricula Duby subsect. Euauricula Pax are mainly distributed in the southern Alps and Pre-Alps, with a very high rate of endemism: of 16-17 species currently recognized, seven are narrowly endemic and restricted to very small areas, four are endemic to various sectors of the southern Alps, and only five have a wider distribution. The subsection extends southwards to reach peninsular Italy with P. auricula-P. balbisii, a species complex distributed across all South European mountain ranges, and with the local endemics P. apennina and P. palinuri. We performed a phylogenetic study employing AFLPs (Amplified Fragment Length Polymorphisms) markers of 260 samples collected in the wild from 33 populations, covering all species, with a focus on the three taxa growing in the Apennine peninsula. We also used DNA sequences of six chloroplast markers of all species. Our purpose was to investigate the relationships of the three peninsular species, and hence to understand whether they are the outcome of a single or of multiple independent colonization events. Our results suggest that: (i) P. apennina belongs to the same calcifuge clade as P. pedemontana and P. cottia, and is the outcome of very recent (late Pleistocene) speciation; (ii) the expansion to peninsular Italy of the problematical P. auricula-P. balbisii species complex represents an independent event; (iii) P. palinuri, the only species of Mediterranean coastal habitats, is not related to P. auricula-P. balbisii in spite of their geographical contiguity and of some morphological similarity; (iv) P. palinuri appears to be most closely related to P. allionii, P. latifolia and P. marginata implying either long-distance dispersal from the west Alps or, more likely, the existence of a now extinct ancestor which was widespread in peninsular Italy. However, the placement of P. palinuri in a phylogenetically derived position is incongruent with an accumulation of plesiomorphic characters in this species which may support its interpretation as a palaeoendemic. (v) our results provide convincing evidence in favour of a "multiple-origin" of the peninsular Auriculas