Data from: Is sexual organ reciprocity related to legitimate pollen deposition in distylous Pulmonaria (Boraginaceae)?

Heterostyly, i.e. the reciprocal positioning of anthers and stigmas, is a floral polymorphism that is thought to promote disassortative (i.e. between-morph) pollination and to maintain genetic diversity within populations. Recent research, however, has shown several cases of heterostylous plant species in which the reciprocal positioning of the sexual organs varies, which may affect the likelihood of ‘legitimate’ pollination between compatible morphs, and hence morph fitness and ultimately the stability of this floral polymorphism. In this study, we investigated floral morphology and stigmatic pollen deposition patterns in nine Pulmonaria species (Boraginaceae) across Europe to test the hypothesis that sexual organ reciprocity is related to legitimate pollen deposition. We used a recently developed adaptive accuracy concept to assess the level of reciprocity and to relate inaccuracies in positioning of sexual organs to legitimate pollen deposition measured on stigmas in the field. The nine investigated Pulmonaria species showed substantial deviations from perfect reciprocity, with total inaccuracies varying between 2.9 and 20.3% relative to the squared mean of all anther and stigma heights in the population. In almost all cases, most of the inaccuracy was generated by the high level organs. Total pollen deposition was always higher on stigmas of long-styled individuals, but stigmas of short-styled individuals received significantly more legitimate pollen than stigmas of long-styled individuals (71.23% and 38.75% respectively). We also found a weak, but significant relationship between measures of inaccuracy and the level of disassortative pollination. Under these conditions of pollen flow, the distylous mating system is predicted to persist in only eleven (27%) of all sampled populations. Overall, these results indicate that deviations from perfect reciprocal herkogamy are common in Pulmonaria and have an impact on legitimate pollen deposition.花柱异长（Heterostyly）指雄蕊与柱头的交互排布，是一类被认为可促进异型间授粉、维持种群内遗传多样性的花部多态性。然而，近期研究已发现若干具花柱异长的植物类群，其生殖器官的交互排布存在变异，这可能影响亲和花型间“合法”授粉的概率，进而影响花型适合度，最终改变该花部多态性的稳定性。 本研究以欧洲分布的9种肺草属（Pulmonaria）植物（紫草科Boraginaceae）为研究对象，调查其花部形态与柱头上的花粉沉积模式，以验证“生殖器官交互排布与合法花粉沉积存在关联”这一假说。本研究采用近年提出的适应性准确度概念，评估生殖器官交互排布的水平，并将生殖器官排布的偏差与野外实测的柱头上合法花粉沉积量相关联。 结果显示，9种受试肺草属植物均与完美的交互雌雄异位（reciprocal herkogamy）存在显著偏差，总偏差率相对于种群内所有雄蕊与柱头高度的平方均值，波动于2.9%至20.3%之间。绝大多数情况下，此类偏差主要源于高位生殖器官。长柱型个体的柱头上总花粉沉积量始终更高，但短柱型个体的柱头所接收的合法花粉量显著高于长柱型个体（分别为71.23%与38.75%）。本研究同时发现，偏差程度与异型间授粉水平之间存在微弱但显著的相关性。在该花粉流条件下，仅11个（占总采样种群的27%）种群可维持二型花柱交配系统。 综上，本研究结果表明，偏离完美交互雌雄异位的现象在肺草属中十分常见，且会对合法花粉沉积产生显著影响。