Data from: Sexual antagonism in the pistil varies among populations of a hermaphroditic mixed-mating plant

Sexual conflicts and their evolutionary outcomes may be influenced by population-specific features such as mating system and ecological context; however, very few studies have investigated the link between sexual conflict and mating system. The self-compatible, mixed-mating hermaphrodite Collinsia heterophylla (Plantaginaceae) is thought to exhibit a sexual conflict over timing of stigma receptivity. This conflict involves 1) delayed stigma receptivity, which intensifies pollen competition, and 2) early fertilization forced by pollen, which reduces seed set. We investigated the potential for the conflict to occur under field conditions and performed greenhouse crosses within eight populations to assess its consistency across populations. Flowers were visited, and produced seeds after pollination, at all developmental stages, suggesting that the conflict can be of significance under natural conditions. In the greenhouse, early pollination imposed costs in all populations. Overall, the timing of first seed set was most strongly affected by the maternal parent, denoting stronger female than male ability to influence onset of stigma receptivity. Crosses also revealed a negative relationship between donor- and recipient-related onset of receptivity within individuals, a novel result hinting at trade-offs in sex-allocation or a history of antagonistic selection. Neither timing of stigma receptivity, timing of first seed set, nor pollen competitive ability covaried with population outcrossing rate. In conclusion, these results indicate that sexually antagonistic selection may be present in varying degrees in different populations of C. heterophylla, but this variation does not appear to be directly related to mating system variation.

性冲突及其演化结局或受种群特异性特征（如交配系统与生态背景）的影响；然而，目前极少有研究探讨性冲突与交配系统之间的关联。被推测具有自交亲和性的混合交配型雌雄同体植物异色柯林草（Collinsia heterophylla，车前科（Plantaginaceae）），存在针对柱头可授性时序的性冲突。该冲突包含两个核心环节：其一为延迟的柱头可授性，该过程会强化花粉竞争；其二为花粉介导的强制早期受精，此过程会降低结籽率。我们在野外条件下探究了该冲突发生的潜在可能性，并在8个种群内开展温室杂交实验，以评估该冲突在不同种群间的一致性。所有发育阶段的花朵均会被访花，且授粉后均可结籽，这表明该冲突在自然条件下或具有重要的生态学意义。在温室实验中，早期授粉在所有种群中均带来了适合度代价。总体而言，首次结籽的时序最显著地受母本调控，这意味着母本对柱头可授性起始时间的影响能力强于父本。杂交实验还揭示了个体内供体与受体相关的可授性起始时序之间存在负相关关系，这一新发现暗示了性分配权衡或拮抗选择历史的存在。无论是柱头可授性时序、首次结籽时序，还是花粉竞争能力，均未与种群异交率呈现共变关系。综上，本研究结果表明，异色柯林草的不同种群中可能存在程度各异的性拮抗选择，但这种差异似乎并不与交配系统的变异直接相关。