Data from: Not all weeds are created equal: a database approach uncovers differences in the sexual system of native and introduced weeds

Weedy species provide excellent opportunities to examine the process of successful colonization of novel environments. Despite the influence of the sexual system on a variety of processes from reproduction to genetic structure, how the sexual system of species influences weediness has received only limited consideration. We examined the hypothesis that weedy plants have an increased likelihood of being self-compatible compared with nonweedy plants; this hypothesis is derived from Baker's law, which states that species that can reproduce uniparentally are more likely to successfully establish in a new habitat where mates are lacking. We combined a database of the weed (weedy/nonweedy) and introduction status (introduced/native) of plant species found in the USA with a database of plant sexual systems and determined whether native and introduced weeds varied in their sexual systems compared with native and introduced nonweeds. We found that introduced weeds are overrepresented by species with both male and female functions present within a single flower (hermaphrodites) whereas weeds native to the USA are overrepresented by species with male and female flowers present on a single plant (monoecious species). Overall, our results show that Baker's law is supported at the level of the sexual system, thus providing further evidence that uniparental reproduction is an important component of being either a native or introduced weed.

杂草类物种为探究物种成功定植新生境的过程提供了绝佳的研究契机。尽管繁育系统（sexual system）对从繁殖到遗传结构的多种过程均存在影响，但物种的繁育系统如何影响其杂草性，却仅得到了有限的关注。我们验证了下述假说：相较于非杂草植物，杂草植物拥有更高的自交亲和（self-compatible）概率；该假说源自贝克法则（Baker's law），即具备单亲繁殖能力的物种，在缺乏交配伙伴的新生境中更易成功定植。我们整合了美国境内植物物种的杂草性分类（杂草/非杂草）、引入状态（外来/本土）数据库与植物繁育系统数据库，以此对比分析本土杂草、外来杂草与本土非杂草、外来非杂草的繁育系统是否存在差异。研究发现，外来杂草中，单花兼具雌雄功能的两性花植物（hermaphrodites）占比显著偏高；而美国本土杂草中，单株同时着生雌雄花的雌雄同株植物（monoecious species）占比更高。总体而言，我们的研究结果在繁育系统层面验证了贝克法则，进一步证明单亲繁殖是本土杂草与外来杂草成功定植的重要核心要素。