DOI: 10.5061/dryad.fb851dn
title: Data from: Release from natural enemies mitigates inbreeding depression in native and invasive Silene latifolia populations

description: Inbreeding and enemy infestation are common in plants and can
 synergistically reduce their performance. This inbreeding × environment
 (I×E) interaction may be of particular importance for the success of plant
 invasions if introduced populations experience a release from attack by
 natural enemies relative to their native conspecifics. Here, we
 investigate whether inbreeding affects plant infestation damage, whether
 inbreeding depression in growth and reproduction is mitigated by enemy
 release and whether this effect is more pronounced in invasive than native
 plant populations. We used the invader Silene latifolia and its natural
 enemies as a study system. We performed two generations of experimental
 out- and inbreeding within eight native (European) and eight invasive
 (North American) populations under controlled conditions using
 field-collected seeds. Subsequently, we exposed the offspring to an enemy
 exclusion and inclusion treatment in a common garden in the species'
 native range to assess the interactive effects of population origin
 (range), breeding treatment and enemy treatment on infestation damage,
 growth and reproduction. Inbreeding increased flower and leaf infestation
 damage in plants from both ranges, but had opposing effects on fruit
 damage in native versus invasive plants. Inbreeding significantly reduced
 plant fitness, whereby inbreeding depression in fruit number was higher in
 enemy inclusions than exclusions. This effect was equally pronounced in
 populations from both distribution ranges. Moreover, the magnitude of
 inbreeding depression in fruit number was lower in invasive than native
 populations. These results support that inbreeding has the potential to
 reduce plant defenses in S. latifolia, which magnifies inbreeding
 depression in the presence of enemies. However, future studies are
 necessary to further explore whether enemy release in the invaded habitat
 has actually decreased inbreeding depression and thus facilitated the
 persistence of inbred founder populations and invasion success. In
 addition, our findings emphasize the importance of purging for for
 successful range expansion.
description: Dataset
 DryadThe dataset bases on a
 common garden experiment with 16 Silene latifolia populations (ac, be, ca,
 ce, cv, es, gi, hg, je, lb, ma, mp, mt, ng, nh, nj) from two different
 distribution ranges (native [eu] versus invasive [us]). N corresponds to
 the latitudinal origin of the regarding population. We exposed plants from
 all populations to a breeding treatment (inbred [i] versus outbred [a])
 using five different maternal families (a, b, c, d, e) per population for
 the experimental crossings. Subsequently inbred and outbred plants were
 exposed to a herbivory treatment (exclusion [ex] versus inclusion [in]),
 which was applied on a plot basis (∑ = 16 plots, of which 8 were
 exclusions [ex] and 8 were inclusions [in]). Individuals within the
 experiment received consecutive numbers. We determined plant sex (female
 [f] versus male [m]), assessed plant growth and reproduction related
 traits (number leaves, aboveground biomass, corolla size, number of
 flowers and buds, number of fruits), as well as traits related to
 infestation damage (damaged leaves, flowers, fruits ) and morphological
 resistance (leaf trichome density).