Abstract Little is known about the reproduction of Dendrocalamus asper because it flowers only every 100 to 120 years. In the present work we describe some reproductive features of this bamboo and characterise flowers and pollen at various developmental stages. Number of pollen grains and ovules per flower, pollen/ovule ratio, in vitro twinning and pollen grain viability in vivo were evaluated and the different stages of floral development identified. Further, we performed a morphological analysis of androecium and pollen development. Seven distinct stages of flower development were identified; four initial stages, a pre-anthetic stage, and two stages of anthetic. Dendrocalamus asper pseudospikelets avoid inbreeding by means of protogyny. The floral and pollen characteristics suggest that the species is anemophilous. The ultrastructural characteristics of free microspores (stage two of floral development), vacuolated microspores (stage five) and mature pollen (anthetic) were analysed. During maturation, pollen grains accumulate larger and more numerous amyloplasts and organelles such as mitochondria. Pollen disperse in the tricellular development stage. Pollen is monoporate with an operculum-like pore, with a rugulate structure and a spinose tectum.

中文翻译：

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竹菖蒲和花粉粒的开花和形态特征

摘要 人们对 Dendrocalamus asper 的繁殖知之甚少，因为它每 100 到 120 年才开花一次。在目前的工作中，我们描述了这种竹子的一些繁殖特征，并表征了不同发育阶段的花和花粉。评估了每朵花的花粉粒数和胚珠数、花粉/胚珠比、体外孪生和体内花粉粒活力，并确定了花发育的不同阶段。此外，我们对雄蕊属和花粉发育进行了形态学分析。确定了花发育的七个不同阶段；四个初始阶段，一个前花期和两个花期。Dendrocalamus asper pseudospikelets 通过原型避免近亲繁殖。花和花粉特征表明该物种是风虫。分析了游离小孢子（花发育的第二阶段）、空泡小孢子（第五阶段）和成熟花粉（花粉）的超微结构特征。在成熟过程中，花粉粒积累了更大和更多的淀粉体和细胞器，如线粒体。花粉在三细胞发育阶段分散。花粉是单孔的，有一个鳃盖状的孔，有皱褶结构和有刺的顶盖。