白麻花蜜腺及花瓣乳突细胞的发育解剖学研究

白麻是中国西北干旱区一种重要的生态型蜜源经济植物，揭示白麻花蜜腺泌蜜的方式和规律对白麻植物资源的开发利用十分必要。以不同花期的新疆产白麻花为试验材料，通过石蜡切片技术和组织化学染色，借助光学显微镜、扫描电镜等仪器，观察研究白麻花蜜腺的形态特征、组织结构及其发生发育规律。研究结果表明：白麻花蜜腺着生于五浅裂的肉质环状花盘裂片上、位于每一花丝基部的内侧，形状为椭圆形，数量5个；蜜腺由分泌表皮、产蜜组织细胞和维管束组成，其中，蜜腺分泌表皮细胞变形突起并随表面角质层形成指状结构。组织化学反应发现，花蜜腺在发育过程中无淀粉粒变化，但具有蛋白质和多糖的消长变化。因此，白麻花泌蜜的可能途径是蜜汁由产蜜组织合成并经由蜜腺表面的指状突起渗透到植物体外，而不是从气孔泌出。此外，白麻花瓣内外表面的单细胞乳突亦具有分泌特性。

Development and Anatomy of Floral Nectaries and Petals Papillae in Apocynum pictum

Apocynum pictum is an important honey source plant with higher ecological and economical value in the arid zone of northwestern China. Clarifying the way and pattern of the Apocynum pictum floral nectar secretion is necessary to plant resources utilization. We investigated the micromorphology and anatomical structure of the flower nectary and petals papillae of Apocynum pictum from Xinjiang arid zone in China by using optical microscope and scanning electron microscope and other instruments. We also performed histochemical tests to determine if nectary is involved in the production of starch grain,proteins and sugar. The results suggested that there are five oval floral nectaries in Apocynum pictum flower in total. The floral nectary distributes in the inner side of the base of each filament on the lobe of five-lobed ring-shaped flower disc. And floral nectary is composed of secretory epidermis,nectarogenic tissue cells and vascular bundles. Among them,the nectary epidermal cells deformed,protruded and formed finger-like structures along with the surface cuticle. In addition,no obvious variation trends were observed in starch grain during the development of nectary. But there was significant fluctuation in protein and sugar at same period. So,the nectar of Apocynum pictum is possibly synthesized by the nectar-producing tissue and secreted from the finger-like protrusions on the surface of the nectary instead of the stomata. In addition,the single-cell papillae with secretory properties were observed on the inner and outer surfaces of petals in Apocynum pictum.