小草蔻花部维管束系统的解剖学研究

Studies on Vascular System Anatomy of the Flower of Alpinia henryi

摘要:

小草蔻花梗的维管束可分成外环和中心区两部分。进入室下区后,外环维管束向外偏移,其数目由约13束增加至约40束;中心区由不规则分布的18束变为三角形排列的12束。延伸至子房室区时,外环基本不变,而原来中心区的维管束则成为3束心皮背束、3束隔膜束及5-7束小的胎座维管束。3束心皮背束外方的主支经延长部最后进入花萼,胎座维管束于延长部基部消失。及至延长部基部,3束隔膜束的内侧横向分支,并最后与部分外环的维管束及心皮背束内方的细小分支在此形成一个维管束网结,而外侧的主支直接向上延伸;近轴面的隔膜束主支分裂成4支最后进入仅有的1枚功能雄蕊,远轴面的2束隔膜束主支则各分成2-3束最后进入唇瓣。延长部的维管束网结部分延伸入花瓣、唇瓣和腺体基部,少量进入花柱。首次提出姜科植物的花萼既代表了3枚花萼片,又包含了3枚缺失的外轮雄蕊;支持姜科的唇瓣代表了两枚缺失的内轮雄蕊及两枚腺体是隔膜腺变异结构的观点。

Abstract:

Outer ring (OR) and central region (CR) of vaseular bundles in pedicel of Alpinia henryi can be recognized . When OR and CR extend into sublocular region,the bundles of OR moves toward outside and increases in number from 13 to 40 scattered CR bundles are arranged into triangle and their number varies from 18 into 12．At the locular region,the CR bundles are arranged as 3 carpellary dorsal bundles, 3 parietal bundles，and 5-7 small placental bundles which fade away at the base ofprolongation．Outer large branches of the three carpellary dorsal bundles finally enter the calyx．At the base of the prolongation, three parietal bundles produce some transverse branches which become vascular plexus with branches of partial bundles and a few smalI branches originated from three carpellary bundles, but their bundles extend directly upwards．Finally，the adaxial parietal bundle splits up into 4 branches which runs up into a functional stamen while the two abaxial parietal bundles split up respectively into 2-3 branches going to the labellum ．The bundles of the vascular plexus finally enter petals，labellum and style．It suggested that the calyx contains not only bundles in three sepals but also in three absent stamens．The authors support the views that the labellum represents two absent stamens ofiilner whorI ofandroecium and the two glands are of modified gynoplural nectary.