State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, 100875, China.
State Key Laboratory of Earth Surface Processes and Resource Ecology, College of life Sciences, Beijing Normal University, Beijing, 100875, China.
Sci Rep. 2017 Dec 18;7(1):17698. doi: 10.1038/s41598-017-17881-2.
The mating system of flowering plants plays a key role during the process of invasion. Evolution from outcrossing to selfing can allow rapid regeneration of a population after long-distance dispersal by providing reproductive assurance. Solanum rostratum is a self-compatible annual herb that exhibits a high level of outcrossing in its native populations. However, the mating system of invasive populations of S. rostratum has never been assessed. Here, we investigated the mating system based on 11 microsatellite loci and explored ecological factors that may influence the outcrossing rate among 10 invasive populations of S. rostratum in China. We found that the mean outcrossing rate was 0.69 ± 0.12 (range 0.49 to 0.83) with multiple paternity within progeny arrays (average effective number of sires = 7.86), which suggests a mixed mating system dominated by outcrossing. Combined with the uniformly high outcrossing rate (0.70 ± 0.03) previously reported in its native range, these results indicate that there has been no evolutionary shift in mating system during the invasion in China by S. rostratum. There were no relationships between outcrossing and population size, population density, altitude, latitude or longitude. Furthermore, high outcrossing of S. rostratum in China may be facilitated by enantiostyly and heteranthery.
植物的交配系统在入侵过程中起着关键作用。从异交向自交的进化可以通过提供生殖保障，允许种群在长距离散布后迅速再生。刺茄是一种自交亲和的一年生草本植物，在其原生种群中表现出高水平的异交。然而，刺茄入侵种群的交配系统从未被评估过。在这里，我们基于 11 个微卫星位点调查了交配系统，并探讨了可能影响中国 10 个刺茄入侵种群异交率的生态因素。我们发现，平均异交率为 0.69±0.12（范围为 0.49 至 0.83），每个后代系谱中有多个父本（平均有效父本数为 7.86），这表明存在以异交为主的混合交配系统。结合之前在其原生范围内报告的均匀高异交率（0.70±0.03），这些结果表明刺茄在中国的入侵过程中交配系统没有进化转变。异交率与种群大小、种群密度、海拔、纬度或经度之间没有关系。此外，刺茄在中国的高异交可能是由对生和异型雄蕊造成的。
