Rubus setchuenensis（Rosaceae） is a high-quality nectariferous plant. In order to clarify the nectar secretion rhythm and morphological characteristics of developmental floral nectary， the floral nectar secretion characteristics were observed and recorded， and morphological and anatomical characteristics and ultrastructure of floral nectary at five developmental stages（young bud stage， flower bud stage， initial flowering stage， full blooming stage and post anthesis stage） were investigated by paraffin section and scanning electronic microscope. The flowering period of R.setchuenensis was from June to November in Meitan County， Guizhou Province， and the vigorous nectar secretion period was from July to September. The flowering period and the nectar secretion period of a single flower were three days and two days， and the average total nectar secretion and total sugar content were （30.58±3.60） μL and （7.14±2.33） mg， respectively. The floral nectary of R.setchuenensis was located on the inner wall of the plate-like receptacle between the stamen base and the ovary， which was composed of epidermis， nectary parenchyma cells and vascular bundle. According to the position and anatomical structure of nectary， and the change of starch granules， floral nectary of R.setchuenensis would be divided into receptacle nectary， structural nectary and starch nectary， respectively. The nectary and epidermal stomata developed from the young bud stage and the budding stage， respectively. The original nectar was provided by the vascular bundle and stored in the nectary cells in the form of starch. The starch granules began to accumulate from the young bud stage， and the starch granule content， size and aperture area of stomata， and thickness of nectary reached the maximum at the initial flowering stage. The nectar was secreted from the cuticles and stomata on nectary epidermis， and the starch granules nearly disappeared at the full blooming stage and the post anthesis stage.
%U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2025.04.015