EFFECTS OF FLORIVORY AND INBREEDING ON REPRODUCTION IN HERMAPHRODITES OF THE WILD STRAWBERRY FRAGARIA VIRGINIANA

摘要

Recently, the biotic context for sexual and mating system evolution in plants has received special attention; however, the significance of interactions with antagonists has only begun to be revealed. We investigated the effect of florivory on reproduction and inbreeding depression by simulating damage on selfed and outcrossed progeny of hermaphrodites of Fragaria virginiana and recording the response of reproduction, as well as measuring tolerance to florivory. While both florivory and inbreeding affected reproduction, their effects were independent with respect to sexual traits but not an asexual trait; inbreeding depression was florivory and family dependent, specifically, for plantlet production. Plants were intolerant of florivory in terms of flowers, moderately tolerant in terms of fruit, and most tolerant in terms of plantlets. However, only under severe damage was intolerance statistically significant. Inbreeding did little to change these patterns. Our findings indicate that florivory does not consistently influence inbreeding depression, suggesting that it is not likely to affect sex ratio through this mechanism. However, our results combined with knowledge of the sex determination system and evidence that florivory increases autogamous selfing suggest a new way florivores could affect sex ratio in this system: that is, by increasing the production of high-fruiting hermaphrodites.