Ant pollination promotes spatial genetic structure in the long-lived plant Borderea pyrenaica (Dioscoreaceae)

Plant survival in alpine habitats is controlled, in several cases, by pollination and seed dispersal success. We have investigated the genetic structure and mating patterns of the endangered Borderea pyrenaica (Dioscoreaceae), one of the oldest herbaceous Pyrenean mountain plants. Simple sequence repeat-based genotyping was carried out on all the reproductive female and male individuals and in all the female-descendent progenies of a population of this plant. Although the offspring sampling (246) was twice the size of the adult sampling (122), the latter group showed higher levels of heterozygosity and approximately 20% more alleles than the offspring. Probabilistic spatial neighbourhood modelling of parentage analysis, based on the exponential-power type model, showed immigration rates of pollen at 63.3%. The present study also detected a strong spatial clustering; most of the sired seeds of B. pyrenaica (68.83%) occurred at distances of up to 20 m, whereas kinship coefficients of adult plants reached zero at spatial distances (d) < 5 m, and 5 < d < 10 m for females and males, respectively. These results support the hypothesis of a terrestrial ant-mediated, rather than a flying insect-mediated pollination in B. pyrenaica. © 2015 The Linnean Society of London.We thank Juan José Robledo-Arnuncio and two anonymous reviewers for their valuable comments and for critically reviewing an earlier version of the manuscript, as well as Emily Lemonds and Douglas Laing for linguistic assistance. The present study has been funded by a Fundación BBVA project grant BIOCON05/093. E. Pérez-Collazos was supported by a Postdoctoral grant from the Fundación BBVA. J. G. Segarra-Moragues was funded by two consecutive Spanish Aragón Government ‘Araid’ and Spanish Ministry of Science and Innovation ‘Ramón y Cajal’ postdoctoral contracts, respectively. The work was partially supported by a Bioflora research group grant, co-funded by the Aragón Government and the European Social Fund.Peer Reviewe