姜花(Hedychium coronarium)花部维管束系统解剖学研究

姜花(Hedychium coronarium Koen.)花梗横切面整体轮廓呈椭圆形,可分为表皮、基本组织和维管束。维管束在基本组织中呈内、外两部分排列。内部维管束联结成网,形成明显外移的三束心皮背束和内方与心皮背束相间的三束隔膜束。至子房室区,心皮背束继续外移,其中主支进入花萼中脉;小分支内移,与内方一轮维管束联结,后来进入唇瓣中央及2枚侧生附属物。在花萼形成的同时,远轴面的两个隔膜中各形成一个上位腺体;同时两束远轴面隔膜束向外、两侧分别形成3束大分支,外方大分支继续外移成为2枚远轴面花瓣中脉,两侧大分支与原外方内移的子房壁维管束集合成一相连的环状维管束网,后进入唇瓣两侧;近轴面隔膜束形成3枚分支,外方分支成为近轴面花瓣中脉,两侧分支进入可育雄蕊。探讨了侧生附属物和唇瓣的来源,支持子房延长部形成的腺体为隔膜蜜腺的变异结构的观点。

Floral Vasculature Anatomy of Hedychium coronarium (Zingiberaceae)

The transverse section of the pedicel of Hedychium coronarium Koen.is oval,including epidermis,the ground tissue and vascular bundles.The periphery vascular bundles surround the inner vascular bundles at the central zone of the pedicel.The inner vascular bundles give rise to 3 carpellary dorsal bundles(CDs) and 3 parietal bundles(PBs) below the locular region.The three CDs are radialized,alternating with the three PBs.In the locular region,the major branches of the three CDs supply 3 sepal midribs,and the small branches extend into the median region of labellum and 2 subulate appendages,accompanied by the portion of the inner bundles.Two abaxial diaphragms form 2 epigynous glands,respectively.The three PBs give rise to 3 strands,respectively.In the abaxial PBs,the outer strands supply abaxial petal midribs and the remaining strands enter into the laterals of labellum.In the baxial PB,the outer strand supplies an abaxial petal midrib,and the lateral strands move into functional stamens.The origins of the subulate appendages and the labellum are discussed.The hypothesis that 2 epigynous glands are special vascularized upward growths from the intramarginal portions of carpels is supported.