Micromorphology and ultrastructure of the floral nectaries of Viola odorata L. (Violaceae)

  • Natalia Wiśniewska University of Gdańsk, Department of Plant Cytology and Embryology, Wita Stwosza 59, 80-308 Gdańsk, Poland
  • Jerzy Bohdanowicz University of Gdańsk, Department of Plant Cytology and Embryology, Wita Stwosza 59, 80-308 Gdańsk, Poland
  • Agnieszka K. Kowalkowska University of Gdańsk, Department of Plant Cytology and Embryology, Wita Stwosza 59, 80-308 Gdańsk, Poland
DOI: https://doi.org/10.5281/zenodo.160363

Abstract

In Viola odorata two inferior anthers have connective appendages (nectaries) projecting into the corolla spur. Nectaries are approx. 4 mm long, elongate, with the top of the nectary bending to the lateral wall of the spur. In the top part and in the abaxial surface of middle part of the nectary all cells have papillae. Nectar is secreted through the modified stomata distributed mainly in the top of nectary The nectary consists of single-layered epidermis, nectary parenchyma and subnectary parenchyma. Features of the nectary parenchyma cells, like dense cytoplasm containing numerous mitochondria and large nuclei, are connected with high metabolic cell activity. The vascularization includes both phloem and xylem. A slight amount of starch in the nectary cells, the profusion of plasmodesmata connecting secretory cells and the presence of vascular bundles suggest that sugars secreted in the nectar were delivered by the phloem sap.

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Fig. 1. Viola odorata: A, B – flowers, each made by five sepals of three kinds in shape, two above alike (AB), two on each side alike (LT) and one that has a spur (SP); C – longitudinal section of nectary consisting of epidermis (E), nectary parenchyma (NP) and subnectary parenchyma (SBN) with vascular bundle (VB) (LM, TBO); D – magnification of C, the top part of the nectary including epidermis (E) and nectary parenchyma (NP), note small cells with densely staining cytoplasm; E – subnectary parenchyma with vascular bundle (VB), containing xylem indicated by arrow; F – nectary parenchyma with phloem cells (asterisks).
Published
2015-05-20
How to Cite
WIŚNIEWSKA, Natalia; BOHDANOWICZ, Jerzy; KOWALKOWSKA, Agnieszka K.. Micromorphology and ultrastructure of the floral nectaries of Viola odorata L. (Violaceae). Modern Phytomorphology, [S.l.], v. 7, p. 59-66, may 2015. ISSN 2227-9555. Available at: <http://ojs.phytomorphology.org/index.php/MP/article/view/85>. Date accessed: 11 apr. 2018. doi: https://doi.org/10.5281/zenodo.160363.
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Issue
Vol 7 (2015)
Section
Research Articles
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