Floral nectar production and carbohydrate composition and the structure of receptacular nectaries in the invasive plant Bunias orientalis L. (Brassicaceae)
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- 作者：Bożena Denisow ; Marzena Masierowska ; Sebastian Antoń
- 关键词：Bunias orientalis ; Nectar secretion and composition ; Receptacular nectaries ; Anatomy and ultrastructure
- 刊名：Protoplasma
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：253
- 期：6
- 页码：1489-1501
- 全文大小：2,847 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
The data relating to the nectaries and nectar secretion in invasive Brassicacean taxa are scarce. In the present paper, the nectar production and nectar carbohydrate composition as well as the morphology, anatomy and ultrastructure of the floral nectaries in Bunias orientalis were investigated. Nectary glands were examined using light, fluorescence, scanning electron and transmission electron microscopy. The quantities of nectar produced by flowers and total sugar mass in nectar were relatively low. Total nectar carbohydrate production per 10 flowers averaged 0.3 mg. Nectar contained exclusively glucose (G) and fructose (F) with overall G/F ratio greater than 1. The flowers of B. orientalis have four nectaries placed at the base of the ovary. The nectarium is intermediate between two nectary types: the lateral and median nectary type (lateral and median glands stay separated) and the annular nectary type (both nectaries are united into one). Both pairs of glands represent photosynthetic type and consist of epidermis and glandular tissue. However, they differ in their shape, size, secretory activity, dimensions of epidermal and parenchyma cells, thickness of secretory parenchyma, phloem supply, presence of modified stomata and cuticle ornamentation. The cells of nectaries contain dense cytoplasm, plastids with starch grains and numerous mitochondria. Companion cells of phloem lack cell wall ingrowths. The ultrastructure of secretory cells indicates an eccrine mechanism of secretion. Nectar is exuded throughout modified stomata.