Abstract:
Floral nectaries have evolved multiple times and rapidly diversified with the adaptive radiation of animal pollinators. As such, floral nectaries exhibit extraordinary variation in location, size, shape, and secretory mechanism. Despite the intricate ties to pollinator interactions, floral nectaries are often overlooked in morphological and developmental studies. As Cleomaceae exhibits substantial floral diversity, our objective was to describe and compare floral nectaries between and within genera. Floral nectary morphology was assessed through scanning electron microscopy and histology across three developmental stages of nine Cleomaceae species including representatives for seven genera. A modified fast green and safranin O staining protocol was used to yield vibrant sections without highly hazardous chemicals. Cleomaceae floral nectaries are most commonly receptacular, located between the perianth and stamens. The floral nectaries are supplied by vasculature, often contain nectary parenchyma, and have nectarostomata. Despite the shared location, components, and secretory mechanism, the floral nectaries display dramatic diversity in size and shape, ranging from adaxial protrusions or concavities to annular disks. Our data reveal substantive lability in form with both adaxial and annular floral nectaries interspersed across Cleomaceae. Floral nectaries contribute to the vast morphological diversity of Cleomaceae flowers and so are valuable for taxonomic descriptions. Though Cleomaceae floral nectaries are often derived from the receptacle and receptacular nectaries are common across flowering plants, the role of the receptacle in floral evolution and diversification is overlooked and warrants further exploration.
摘要:
随着动物传粉者的适应性辐射,花蜜腺已经进化了多次,并迅速多样化。因此,花卉蜜腺在位置上表现出非凡的变化,尺寸,形状,和分泌机制。尽管与传粉媒介的互动有着错综复杂的联系,花蜜腺在形态学和发育研究中经常被忽视。由于Cleomaceae表现出大量的花卉多样性,我们的目的是描述和比较属之间和属内的花蜜腺。通过扫描电子显微镜和组织学评估了9种Cleomaceae物种的三个发育阶段的花蜜腺形态,其中包括7个属的代表。使用改良的快速绿色和番红O染色方案来产生没有高度危险化学品的充满活力的切片。库利科花蜜腺最常见的是接受的,位于花被和雄蕊之间。花蜜腺由脉管系统提供,通常含有蜜腺薄壁组织,并有尸检。尽管共享位置,组件,和分泌机制,花卉蜜腺在大小和形状上表现出惊人的多样性,从轴向突起或凹陷到环形盘。我们的数据显示,正面和环形的花蜜腺散布在整个Cleomaceae中,形式上具有实质性的不稳定性。花蜜腺有助于菊科花的巨大形态多样性,因此对于分类学描述很有价值。尽管Cleomaceae花蜜腺通常来自容器,并且在开花植物中很常见,花托在花卉进化和多样化中的作用被忽视,值得进一步探索。