Eriocaulaceae表现出与昆虫相关的多种花卉特征(例如蜜腺结构)和风授粉(单性花,暴露的性器官和小花粉粒),以及“自交综合症”(小花,柱头和花药之间的短距离,以及男性和女性阶段的时间重叠)。Paepalanthusbiddus,枯草芽孢杆菌和丁草芽孢杆菌是形式不同的相关物种,花卉结构的大小和颜色。我们旨在研究这三个物种的授粉和生殖生物学。
我们分析了花卉生物学,花卉游客,传粉者的行为,以及昆虫的贡献,风和自发的geitonogamy坐果。我们还评估了该物种的花色和气味。测量了每个物种的头孢的颜色反射率,并在昆虫视觉模型中进行了绘制。提取花香样品,并将化合物与植物气味样品进行比较。
在所有物种中,雄花和雌花以交替的周期排列,这些阶段之间有时间重叠。蚂蚁是最常见的花卉游客,并且是双歧杆菌和丁氏疟原虫的有效传粉者,而苍蝇偶尔是P.tortilis的传粉者。在枯草芽孢杆菌中未观察到花卉访客。在所有物种中,水果是由自发的geitonogamy产生的,没有风授粉的证据.根据昆虫视觉模型,对于蚂蚁和苍蝇来说,双歧杆菌和枯草杆菌的头状花的颜色是最不显眼的。我们发现花序挥发物的排放与营养结构之间没有差异。
这项研究表明,蚂蚁授粉可能比目前假设的更广泛。此外,对于小型单果植物,混合交配策略是最有利的,通过在授粉者丰富时通过异交或在授粉稀缺/不存在时通过自发的地理婚制来确保繁殖。
Eriocaulaceae exhibit a great variety of floral traits associated with insect (e.g. nectariferous structures) and wind pollination (unisexual flowers, exposed sexual organs and small pollen grains), as well as the \'selfing syndrome\' (small flowers, short distance between stigma and anthers, and temporal overlap of male and female phases). Paepalanthus bifidus, P. subtilis and P. tortilis are related species that differ in form, size and colour of floral structures. We aimed to investigate the pollination and reproductive biology of these three species.
We analysed the floral biology, floral visitors, pollinator behaviour, and the contribution of insects, wind and spontaneous geitonogamy to fruit set. We also evaluated the floral colour and scent of the species. Colour reflectance of capitula of each species was measured and plotted in models of insect vision. Floral scent samples were extracted and the compounds were compared to vegetative scent samples.
In all species, the staminate and pistillate flowers are arranged in alternating cycles with a temporal overlap between these phases. Ants were the most frequent floral visitors and were effective pollinators in P. bifidus and P. tortilis, while flies were occasional pollinators in P. tortilis. Floral visitors were not observed in P. subtilis. In all species, fruits were produced by spontaneous geitonogamy, with no evidence of wind pollination. According to the models of insect vision, the colours of the capitula of P. bifidus and P. subtilis are the most inconspicuous for ants and flies. We found no difference between the emission of volatiles of inflorescences and vegetative structures.
This study suggests that ant pollination might be more widespread in Eriocaulaceae than currently assumed. Furthermore, for small monocarpic plants, mixed mating strategies are most favourable, by ensuring reproduction either by outcrossing when pollinators are abundant or by spontaneous geitonogamy when pollinations are scarce/absent.