群心菜花蜜腺的发育解剖学研究

DEVELOPMENTAL AND ANATOMIC STUDIES ON THE FLORAL NECTARIES IN CARDARIA DRABA

群心菜（Ｃａｒｄａｒｉａｄｒａｂａ（Ｌ．）Ｄｅｓｖ．）花蜜腺６枚，包括４枚侧蜜腺和２枚中蜜腺，属十字花科侧中蜜腺类型中的侧分离中间亚型。侧中蜜腺结构相同，都由分泌表皮、产蜜组织组成。分泌表皮顶部分布有变态气孔器，产蜜组织中无维管束分布，属较原始的十字花科花蜜腺亚型类型。在花的各部分基本分化完成后，由花托表层细胞恢复分裂能力形成蜜腺原基。蜜腺原基经分裂、分化和形态建成，发育形成成熟蜜腺，侧中蜜腺发生发育同步。在蜜腺发育过程中，产蜜组织中液泡和淀粉粒发生有规律的变化。其原蜜汁在产蜜组织中加工合成后，通过变态气孔泌出。

Anatomic studies and cytological observation of the floral nectary in Cardaria draba (L.) Desv. are conducted with light and scanning electron microscopy. The Cardaria draba flower has six floral nectaries which include four lateral and two median nectaries. Their floral nectaries belong to the spearate lateral and between median subtypes of the lateral nectary types. The structure of lateral and median nectaries is exhibiting similar structural features. They are composed of epidermis and nectariferous tissure. The modified stomata is present in the epidermal layer, and there is no vascular bundle in the nectariferous tissue, belonging to the primitive subtypes of floral nectaries in Cruciferae. After various floral organs develop, the superfical layer cells of the receptacle between stamens become matic activity and form the primordium nectaries, which undergo the division and differentiation as well as formation of morphology. As a result, the nectaries has developed to mature ones. The initaition and development of lateral and median nectaries form synchronism. During the development of nectary, both the vacules and the starch grains change regularly. After pre-nectar has been processed and composed in the nectariferous tissue, it is excreted from the modified stoma.