Comparative population genetic structure in a plant–pollinator⁄seed predator system

MAGALHAES, I. S.; GLEISER, G.; LABOUCHE, A-M.; BERNASCONI, G.

MOLECULAR ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 vol. 20 p. 4618 - 4630

0962-1083

Comparative analyses of spatial genetic structure of populations of plants and the insectsthey interact with provide an indication of how gene flow, natural selection and geneticdrift may jointly influence the distribution of genetic variation and potential for local coadaptation for interacting species. Here, we analysed the spatial scale of genetic structurewithin and among nine populations of an interacting species pair, the white campionSilene latifolia and the moth Hadena bicruris, along a latitudinal gradient acrossNorthern ⁄ Central Europe. This dioecious, short-lived perennial plant inhabits patchy,often disturbed environments. The moth H. bicruris acts both as its pollinator andspecialist seed predator that reproduces by laying eggs in S. latifolia flowers. We usednine microsatellite markers for S. latifolia and eight newly developed markers forH. bicruris. We found high levels of inbreeding in most populations of both plant andpollinator ⁄ seed predator. Among populations, significant genetic structure was observedfor S. latifolia but not for its pollinator ⁄ seed predator, suggesting that despite migrationamong populations of H. bicruris, pollen is not, or only rarely, carried over betweenpopulations, thus maintaining genetic structure among plant populations. There was aweak positive correlation between genetic distances of S. latifolia and H. bicruris. Theseresults indicate that while significant structure of S. latifolia populations creates thepotential for differentiation at traits relevant for the interaction with the pollinator ⁄ seedpredator, substantial gene flow in H. bicruris may counteract this process in at least somepopulations.