Floral micromorphology of the Australian carnivorous bladderwort Utricularia dunlopii, a putative pseudocopulatory species

详细信息    查看全文

• 作者：Bartosz J. Płachno ; Małgorzata Stpiczyńska ; Piotr Świątek ; Kevin L. Davies
• 关键词：Bladderwort ; Carnivorous plant ; Lentibulariaceae ; Micromorphology ; Osmophore ; Pollination ; Sect. Pleiochasia ; Sexual deceit ; Ultrastructure
• 刊名：Protoplasma
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：253
• 期：6
• 页码：1463-1473
• 全文大小：2,555 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Cell Biology
  Plant Sciences
  Zoology
  
• 出版者：Springer Wien
• ISSN：1615-6102
• 卷排序：253

文摘

Flowers of sexually deceptive taxa generally possess a set of morphological and physiological characters that mimic their insect pollinators. These characters often include a specific insect-like floral configuration, together with scent glands (osmophores) that produce fragrances which chemically resemble insect sex pheromones. Furthermore, these flowers tend not to produce pollinator food rewards. According to some authors, flowers of the Australian bladderwort Utricularia dunlopii (and species of the Utricularia capilliflora complex) resemble insects, and pollination perhaps occurs by pseudocopulation. The aims of this paper are to compare the structure and distribution of floral glandular trichomes in the Australian carnivorous plant U. dunlopii with those of closely related species assigned to the same section and to discuss their putative function. Floral tissues of U. dunlopii P. Taylor, Utricularia paulinae Lowrie, Utricularia dichotoma Labill. and Utricularia uniflora R.Br. (section Pleiochasia) were investigated using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. In U. dunlopii, two long, erect, filiform appendages arising from the upper lip of the corolla, together with three arising from the lower lip, bear numerous glandular trichomes that may function as osmophores. In other species, such as U. uniflora and U. paulinae, glandular papillae on the corolla palate may also function as osmophores. The floral anatomical and morphological organisation of U. dunlopii differs from that of the other investigated species, indicating that its insect pollinators are also likely to differ. Morphological and ultrastructural observations, while generally contributing to our understanding of the flower of U. dunlopii, do not refute the possibility that pollination here may occur by pseudocopulation. Further field-based investigations, however, are now necessary to test this hypothesis.