寒兰花器官发生及花发育过程的研究

Floral Ontogeny and Development of Cymbidium kanran Makino

为了揭示寒兰的成花机理,利用石蜡切片和花芽实体解剖记录了濒危植物寒兰花芽分化和发育的过程,并着重观察唇瓣和合蕊柱早期及中期的发育(在合蕊柱伸长之前)。结果表明:寒兰花芽分化沿着花序轴从下往上可分为4个阶段:花序原基分化,花原基分化,花被片分化和合蕊柱形成。唇瓣分化分为3个阶段:褶片分化,侧裂片分化和色块形成。唇瓣侧裂片和褶片产生较晚,与退化雄蕊可能没有关系。在合蕊柱形成过程中,首先分化出花药,随后分化产生中心皮顶部,侧心皮顶部,并形成花柱道,最终分化出蕊喙和黏盘。

In order to reveal flower formation mechanism of Cymbidium kanran Makino,we documented the floral ontogeny and development of this endangered orchid species by paraffin section and anatomy,with focus on the primitive and middle develop stages of labellum and gynostemium(before the elongation of the column part).Results show that:the differentiation process of inflorescence is acropetal and follows the sequence:inflorescence primordium differentiation,floral primordium differentiation,perianth differentiation,and gynostemium formation.Differentiation of the labellum follows the sequence:lamella,side-lobes,and purplish red patches on the mid-lobe and stripes on the side-lobes.Because of the late initiation of the side-lobes and lamella of the labellum,they may not be related to the staminodes.During the formation of gynostemium,anther initiates first,then the median carpel apex and lateral carpel apices emerge,stigmatic channel forms,and finally the rostellum and viscidium differentiate.