同域分布的紫堇属三种植物的繁育系统和传粉差异

Differentiation in breeding system and pollination of three sympatric Corydalis species

为研究近缘物种之间繁育系统分化对传粉环境的适应性意义,本文针对湖北地区的3种紫堇属植物(紫堇Corydalis edulis Maxim.、尖距紫堇C.sheareri S.Moore.和小花黄堇C.racemosa(Thunb.)Pers.)进行了传粉生态学研究,对比分析了它们在花部特征、分布模式、花期、交配系统、传粉系统等方面的差异。3种紫堇属植物常见伴生现象,花期有一定重叠;花色、距长、花蜜量等方面均有显著差异;尖距紫堇交配系统为自交不亲和、依靠传粉者异花授粉;而紫堇和小花黄堇交配系统为自交亲和,兼有自交和异交的混合交配系统。3个物种均由蜂类传粉,且花部性器官与传粉者的接触部位一致,但访花频率差异较大。在混合群落中,传粉者访花具有较高的忠实性,花部特征差异可能是传粉者选择性访花的原因。对于紫堇属3个物种,花部特征和交配系统的分化有助于其避免传粉过程的相互干扰,交配系统与传粉环境具有一定相关性,混合交配系统可能有利于提高植物对不同生境和气候的适应性。

To illustrate the adaptive significance of breeding system differentiation to pollination environments,we studied the floral traits,distribution patterns,flowering phenology,mating system,and pollination system of three sympatric Corydalis species（ Corydalis edulis Maxim.,C. sheareri S. Moore.,and C. racemosa（ Thunb.） Pers.） in Hubei Province,China. Results showed that the three species usually co-occurred in plant communities and the flowering phase overlapped to some extent. Their floral traits diverged in color and size of corolla,as well as nectar production. Corydalis sheareri was self-incompatible,depending on crosspollination by pollinators,whereas C. edulis and C. racemose were self-compatible and had mixed mating systems,reproducing through both autogamy and cross-pollination. All three species shared their main pollinators（ bumblebees,honeybees,and leafcutter bees） and the floral sexual organs contacted the same body parts of the pollinators, but the visitationfrequency differed significantly. In the mixed plant community,the pollinators constantly visited flowers of the same species,probably due to differences in floral morphology. In conclusion,the divergence in floral traits and mating systems might contribute to the avoidance of pollination interference among related species. The mating systems might be associated with the pollination environment,and those species with mixed mating systems showed advantages at adapting to different habitats and climates.