摘要

Tertiary geological processes and Quaternary climatic oscillations significantly contributed in determining plant species ranges in the Mediterranean basin, making it difficult to distinguish between relative influence of habitat fragmentation and long-distance dispersal in shaping actual species distribution across disjointed regions. We studied the phylogeographic structure of Anacamptis longicornu, a Western Mediterranean orchid species spanning over the main continental islands (Sicily, Sardinia, Corsica, Balearic Islands) and North Africa. We aimed to answer the question whether the highly disjointed distribution of this orchid was determined by: (1) recent over-sea dispersion after the last glacial phase; (2) range fragmentation after the refilling of Mediterranean basin at the end of the Messinian Salinity Crisis (MSC); (3) ancient dispersal events linked to the insurgence of favourable bioclimatic conditions in the basin. Haplotype differentiation, haplotype network, and mismatch analysis support the hypothesis that the current distribution of A. longicornu is more likely explained by allopatric separation and restricted gene flow in connection with fragmentation of a continuous range or a series of ancient dispersal events, after the MSC but before the most recent glaciations. Recent over-sea dispersion, if occurring, must have played a marginal role.

  • 出版日期2011-8