Anatomical Structure and Ultrastructure of Female Floral Nectaries in Eleutherococcus senticosus

Female floral nectary of Eleutherococcus senticosus was observed by optical microscope,SEM and TEM.The results showed that:(1)Flower disc nectary of Eleutherococcus senticosus consisted of epidermis and nectariferous tissue;(2)Numerous modified stomata were scattered uniformly across the surface of nectary,from where nectar exuded;(3)A large number of starch grains accumulated in nectariferous cells served as the main source of nectar sugars and regular changes of vacuoles occurred;(4)It could not be determined whether the process of elimination of the nectar is solely eccrine or partly granulocrine;(5)Sections stained with auramine O under fluorescence microscope showed that the epidermis of the nectary was covered by a thickened cuticle;Microchannels ran through thickened cuticle might be one of the ways for nectar secretion.