Abstract This micromorphological, chemical and ultrastructural study is a continuation of research conducted on fly-pollinated species. The aim of proposed project is to examine the features of floral secretory tissue of stapeliads (Eudicots, Apocynaceae, Asclepiadoideae) and compare them with previously published Bulbophyllum species (Monocots, Orchidaceae, Epidendroideae). The Echidnopsis cereiformis and Stapelia scitula flowers comprised features that characterize a fly-pollinated syndrome. Secretory activity was observed on the adaxial (upper) surface of flowers of both species, however, the chemical composition of secretion differs between species. In S. scitula it is lipid-rich material, whereas in E. cereiformis it is protein-rich. The ultrastructural studies revealed dense cytoplasm in the epidermis and subepidermal tissue with large nuclei and numerous mitochondria, the profiles of SER and RER, and dictyosomes. Large amounts of secreted material were present on the cuticle surface, similar to the unusual prominent periplasmic space with flocculent secretory material. The most remarkable feature was the presence of a prominent periplasmic space in the epidermal cells of S. scitula. Interestingly, subcuticular spaces have been noted only in a few other species, including three orchids from the section Lepidorhiza. Since Asclepiadaceae and Orchidaceae share other features which developed independently, such as pollen mass coherent in pollinia, presence of a periplasmic space could have also developed as a consequence of pollinators pressure and could be a feature important taxonomically.

中文翻译：

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由苍蝇（双翅目）授粉的两个物种花分泌结构的微形态学、组织化学和超微结构分析

摘要 这项微形态学、化学和超微结构研究是对蝇类授粉物种研究的延续。拟议项目的目的是检查葡萄藤（Eudicots、夹竹桃科、Asclepiadoideae）的花分泌组织的特征，并将它们与以前发表的Bulbophyllum物种（单子叶植物、Orchidaceae、Epidendroideae）进行比较。Echidnopsis cereiformis 和 Stapelia scitula 花包含表征苍蝇授粉综合征的特征。在两个物种的花的近轴（上）表面都观察到分泌活动，但是，分泌物的化学成分因物种而异。在 S. scitula 中，它是富含脂质的物质，而在 E. cereiformis 中，它富含蛋白质。超微结构研究揭示了表皮和表皮下组织的细胞质致密，细胞核大，线粒体众多，SER 和 RER 的特征，以及 dictyosomes。角质层表面存在大量分泌物，类似于具有絮状分泌物的异常突出的周质空间。最显着的特征是在 S. scitula 的表皮细胞中存在显着的周质空间。有趣的是，仅在少数其他物种中发现了皮下空间，包括来自 Lepidorhiza 部分的三种兰花。由于针叶科和兰科具有其他独立发展的特征，如花粉块中的花粉团一致，