PREMISE Inbreeding depression is well documented in flowering plants and adversely affects a wide range of fitness-related traits. Recent work has begun to explore the effects of inbreeding on ecological interactions among plants and other organisms, including insect herbivores and pathogens. However, the effects of inbreeding on floral traits, floral scents, and pollinator visitation are less well studied. METHODS Using inbred and outbred maternal families of horsenettle (Solanum carolinense, Solanaceae), we examined the effects of inbreeding on traits associated with pollinator attraction and floral rewards. Specifically, we measured corolla size, counted pollen grains per flower, and analyzed floral volatile emissions via gas chromatography and mass spectrometry. We also examined pollinator visitation to experimental arrays of flowering inbred and outbred plants under field conditions. RESULTS Compared to those of outbred plants, flowers of inbred plants exhibited reduced corolla size and pollen production, as well as significantly reduced emission of the two most abundant volatile compounds in the floral blend. Furthermore, bumblebees-the main pollinators of horsenettle-discriminated against inbred flowers in the field: bees were more likely to make initial visits to flowers on outbred plants, visited outbred flowers more often overall, and spent more time on outbred flowers. CONCLUSIONS These results show that inbreeding can (1) alter floral traits that are known to mediate pollinator attraction; (2) reduce the production of floral rewards (pollen is the sole reward in horsenettle); and (3) adversely affect pollinator visitation under field conditions.

中文翻译：

---

Solanum carolinense 的近亲繁殖改变了花卉引诱剂和奖励，并对传粉媒介的访问产生不利影响

前提 近交衰退在开花植物中得到充分证明，并对各种与健康相关的性状产生不利影响。最近的工作已经开始探索近亲繁殖对植物和其他生物（包括昆虫食草动物和病原体）之间生态相互作用的影响。然而，近亲繁殖对花卉性状、花卉气味和传粉者访问的影响研究较少。方法使用马荨麻（Solanum carolinense，茄科）的近交和远交母系，我们检查了近交对与传粉媒介吸引力和花卉奖励相关的性状的影响。具体来说，我们测量了花冠大小，计算了每朵花的花粉粒数，并通过气相色谱法和质谱法分析了花的挥发性排放物。我们还检查了传粉者在田间条件下对开花近交和远交植物的实验阵列的访问。结果与远交植物相比，近交植物的花表现出花冠大小和花粉产量的减少，以及花卉混合物中两种最丰富的挥发性化合物的排放量显着减少。此外，大黄蜂——马荨麻的主要传粉者——在田间歧视近交花卉：蜜蜂更有可能对远交植物的花朵进行初步访问，总体上更频繁地访问远交花卉，并在远交花卉上花费更多时间。结论 这些结果表明，近交可以 (1) 改变已知介导传粉媒介吸引力的花卉特征；(2) 减少花粉奖励的产生（花粉是马荨麻中唯一的奖励）；