【目的】探讨紫竹(Phyllostachys nigra) 结实率低的原因。【方法】以西南林业大学珍稀竹种园内的紫竹为材料,对紫竹花器官、大小孢子发生及雌雄配子体的发育进行显微观察。【结果】紫竹花序为有限花序,顶端小花先开放,基部小花随后开放,小穗簇生,小穗基部具有潜伏芽。紫竹花为开放型小花,由内外稃各1枚、3枚雄蕊、1枚雌蕊以及3枚浆片5部分组成,浆片膜状透明,边缘具有发达的纤毛。紫竹的花药长约8 mm,具有两两对称的4 药囊。造孢时期的花药壁由4层结构构成,由外到内分别是表皮、药室内壁、中层和绒毡层。花药成熟后可形成二核、三核花粉粒,花药壁只有2层。紫竹小花子房单室,侧膜胎座,倒生胚珠,羽毛状柱头3裂。【结论】紫竹小花雄蕊发育过程中出现多种发育异常情况,这应该是导致紫竹结实率过低的关键原因。

【Objective】The flower morphological structure and anther abortion of Phyllostachys nigra are analyzed to explore the reasons for its low seed-set rate.【Method】The flower organs, mega- and microsporogenesis, as well as the development of male and female gametophytes, are observed through morphological examinations of the spikelets and paraffin sections using flower samples of P. nigra from the bamboo garden at the Southwest Forestry University. 【Result】The P. nigra inflorescence is a limited inflorescence, with the florets at the top blooming first, followed by the florets at the bottom. The spikelets cluster at the nodes of floral branches, with latent buds located at the base of the spikelets. The Ph. nigra florets are open, containing one palea, one lemma, three stamens, three lodicules, and one pistil. The lodicules are membranous and transparent, with well-developed cilia along the edges. The anther of P. nigra is approximately 8 mm long, containing four symmetrical sporangia. At the sporogenous cell stage, the anther wall consists of four layers: epidermis, endothecium, middle layer, and tapetum, from the outside to the inside. After anther maturation, two-celled or three-celled pollen grains are produced, and the anther wall comprises only two layers. The ovary is unilocular with parietal placentation, containing an anatropous ovule and three-lobed, feathery stigmata. 【Conclusion】Multiple abortions occur during the development of the stamens, which can be the key reason for the low seed-set rate of P. nigra.