荆条花蜜腺发育解剖学研究

DEVELOPMENTAL AND ANATOMICAL STUDIES ON THE FLORAL NECTARY IN VITEX CHINENSIS

荆条 (Vitex chinensis Mill.)花蜜腺属于淀粉型子房蜜腺 ,呈圆筒状环绕于子房的基部。蜜腺外观上无特殊结构 ,表面平滑。由分泌表皮和泌蜜组织组成 ,包括分泌表皮、气孔器、泌蜜薄壁组织和维管束。蜜腺和子房壁起源相同。花蕾膨大期 ,泌蜜组织细胞中产生大液泡 ;露冠期 ,泌蜜组织中形成维管束 ;花蕾初放期 ,分泌表皮细胞分化形成气孔器 ,无气孔下室 ,淀粉粒的积累在此期达到高峰 ;盛花期 ,蜜腺中已无淀粉粒 ,蜜腺通过气孔将蜜汁排出 ,开花前期到盛花期泌蜜量最大 ,以后逐渐减弱 ;花败期停止泌蜜。

The morphological structure and the development process of floral nectary in Vitex chinensis Mill.were investigated with the methods of paraffin,scanning electron microscope and histochemistry.The results are as follows:The floral nectary of V.Chinensis belongs to ovarial nectary of starch storing and it surrounds base of orary.The nectary has smooth surface, and it consists of secretary epidermis and nectariferous tissue,includs secretary epidermis,stomata,nectariferous parenchyma and vascular bundle.The floral nectary and the wall of ovary are all come from the same primordium of pistil.At the stage of bud enlargement,vacuole takes form in the cells of nectariferous tissue;at the stage of flower revealing its corolla,vascular bundle takes form in nectariferous tissue;stomata,which has no substomatal chamber,differentiates and takes form from epidermis at early anthesis,and at the same stage starch reaches the peak;Starch disapears at anthesis.The nectary excretes nectar from stomata,a great amount of nectar is secreted during the period of early anthesis to anthesis.The quantity of nectar secretion is decreased gradually, and stopped when flower withered.It is a thorough secretion that almost all the substance in the cells of nectariferous tissue transfered into nectar.