Abstract：
OBJECTIVE: The ability to self-fertilize is predicted to provide an advantage in colonization because a single individual can reproduce and establish a next generation in a new location regardless of the density of mates. While there is theoretical and correlative support for this idea, the strength of mate limitation as a selective agent has not yet been delineated from other factors that can also select for self-fertilization in colonization of new habitats. We used known mating-system variation in the American bellflower (Campanula americana) to explore how plants\' ability to self-fertilize can mitigate density-dependent reproduction and impact colonization success.
METHODS: We created experimental populations of single individuals or a small number of plants to emulate isolated colonization events. These populations were composed of plants that differed in their ability to self-fertilize. We compared pollen limitation of the single individuals to that of small populations.
RESULTS: Experimental populations of plants that readily self-fertilize produced consistent seed numbers regardless of population size, whereas plants with lower ability to self-fertilize had density-dependent reproduction with greater seed production in small populations than in populations composed of a single individual.
CONCLUSIONS: We experimentally isolated the effect of mate limitation in colonization and found that it can select for increased self-fertilization. We show the benefit of self-fertilization in colonization, which helps to explain geographic patterns of self-fertilization and shows support for Baker\'s law, a long-held hypothesis in the field of mating-system evolution.
METHODS: We created experimental populations of single individuals or a small number of plants to emulate isolated colonization events. These populations were composed of plants that differed in their ability to self-fertilize. We compared pollen limitation of the single individuals to that of small populations.
RESULTS: Experimental populations of plants that readily self-fertilize produced consistent seed numbers regardless of population size, whereas plants with lower ability to self-fertilize had density-dependent reproduction with greater seed production in small populations than in populations composed of a single individual.
CONCLUSIONS: We experimentally isolated the effect of mate limitation in colonization and found that it can select for increased self-fertilization. We show the benefit of self-fertilization in colonization, which helps to explain geographic patterns of self-fertilization and shows support for Baker\'s law, a long-held hypothesis in the field of mating-system evolution.
摘要：
目的：预测自我受精的能力在定殖中提供了优势，因为无论配偶的密度如何，单个个体都可以在新的位置繁殖并建立下一代。虽然这个想法有理论和相关的支持，作为选择剂的配偶限制的强度尚未与其他因素区分开来，这些因素也可以在新栖息地的定植中选择自我受精。我们使用已知的交配系统变异的美国风铃草（风铃草）来探索植物的自我受精能力如何减轻密度依赖性繁殖并影响定植成功。
方法：我们创建了单个个体或少量植物的实验种群以模拟分离的定殖事件。这些种群由自体受精能力不同的植物组成。我们将单个个体的花粉限制与小种群的花粉限制进行了比较。
结果：无论种群大小，容易自体受精的植物的实验种群产生一致的种子数量，而自体受精能力较低的植物具有密度依赖性繁殖，与由单个个体组成的种群相比，小种群的种子产量更高。
结论：我们通过实验分离了配偶限制在定植中的作用，并发现它可以选择增加的自体受精。我们展示了自我受精在定植中的好处，这有助于解释自体受精的地理模式，并显示对贝克定律的支持，交配系统进化领域的一个长期假设。
方法：我们创建了单个个体或少量植物的实验种群以模拟分离的定殖事件。这些种群由自体受精能力不同的植物组成。我们将单个个体的花粉限制与小种群的花粉限制进行了比较。
结果：无论种群大小，容易自体受精的植物的实验种群产生一致的种子数量，而自体受精能力较低的植物具有密度依赖性繁殖，与由单个个体组成的种群相比，小种群的种子产量更高。
结论：我们通过实验分离了配偶限制在定植中的作用，并发现它可以选择增加的自体受精。我们展示了自我受精在定植中的好处，这有助于解释自体受精的地理模式，并显示对贝克定律的支持，交配系统进化领域的一个长期假设。
