DEVELOPMENTAL AND ANATOMICAL STUDIES ON THE FLORAL NECTARY IN VITEX CHINENSIS

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.