Spatial (herkogamy) or temporal (dichogamy) separation of sex organs are mechanisms considered to restrict self-pollination and promote outcrossing. Additionally, avoidance of self-interference is proposed to be the driving force for the evolution of these mechanisms, particularly in self-incompatible species. However, species with anthers and stigmas at different levels may increase the rate of imprecise pollen transfer, resulting in pollen discounting. Non-reciprocal stylar dimorphism has been considered a transitional, unstable stage towards the evolution of reciprocal style dimorphism (distyly), to simultaneously avoid interference and lack of precision. In this study we investigate the spatial and temporal separation of sex organs in a population of the style dimorphic and self-incompatible Narcissus broussonetii and their consequences in the reciprocity between the sex organs of morphs and their fecundity. First, we evaluated the relative growth of sex organs after anthesis. Then, we studied the stigma receptivity along the flower lifespan including its effect on seed production in both morphs. Finally, given the weak reciprocity between the sex organs of morphs of this species, we estimated population genetic diversity parameters in Long- and Short-styled plants to explore differences between them as a result of rates of inbreeding due to different mating strategies. We observed that Long-styled plants and Short-styled plants present different strategies to avoid sexual interference and both of them had negative consequences in the reciprocity between the sex organs of morphs. Long-styled plants exhibited a delay in stigma receptivity and a higher growth rate of the style after anthesis, while Short-styled plants presented higher herkogamy and no delay in stigma receptivity. These findings suggest that the avoidance of self-interference, in stylar dimorphic Narcissus species, seems to be more critical than improving of reciprocity between the sex organs of morphs. This might explain why reciprocal herkogamy (distyly) is rare in the genus.

中文翻译：

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避免性干扰：水仙（石蒜科）花柱二形花中的雌雄同株和雌雄异株。

性器官的空间（雌雄同体）或时间（雌雄异体）分离被认为是限制自花授粉和促进异交的机制。此外，避免自干扰被认为是这些机制进化的驱动力，特别是在自交不亲和的物种中。然而，具有不同水平花药和柱头的物种可能会增加不精确的花粉转移率，导致花粉折扣。非互惠花柱二态性被认为是向互惠花柱二态性（遥远）演化的过渡、不稳定阶段，以同时避免干扰和缺乏精确性。在这项研究中，我们研究了两态性和自交不亲和水仙种群中性器官的空间和时间分离及其对变体性器官与其繁殖力之间相互作用的影响。首先，我们评估了开花后性器官的相对生长。然后，我们研究了花寿命期间的柱头接受性，包括其对两种形态种子生产的影响。最后，考虑到该物种变体性器官之间的弱互惠性，我们估计了长柱和短柱植物的种群遗传多样性参数，以探讨它们之间由于不同交配策略而导致近交率的差异。我们观察到，长柱植物和短柱植物呈现出不同的避免性干扰的策略，并且它们都对变体性器官之间的相互作用产生负面影响。长花柱植物表现出柱头可受性延迟和花后花柱生长速率较高，而短花柱植物表现出较高的雌花受精性并且柱头可受性没有延迟。这些发现表明，在花柱二态性水仙属物种中，避免自我干扰似乎比改善形态性器官之间的互惠性更为重要。这也许可以解释为什么互惠雌雄同配（distyly）在该属中很少见。