舞花姜花部维管束系统的解剖学研究

对舞花姜(Globba racemosa)花部维管束系统进行解剖学观察分析,以探讨其缺失雄蕊的去向及其唇瓣和腺体结构的属性.结果显示:(1)舞花姜花梗部的维管束分散排列在基本组织内.(2)子房基部的维管束排成2部分,中央区为分散排列的小维管束,外方为一轮大维管束环,且外环维管束发育为子房壁维管束,心皮背束和隔膜束均起源于中心区维管束,二者的分支在延长部形成一个维管束网结;在网结之上,近轴面的两束心皮背束分支分别进入到2枚侧生退化雄蕊中并成为其主束,远轴面心皮背束的内方分支则成为唇瓣中束,三束心皮背束的其余分支均上行入萼片.(3)唯一1枚功能雄蕊接受近轴面隔膜束的内方主支作为其主束,远轴面2枚隔膜束的主支最后进入唇瓣的两侧束,三束隔膜束的外分支均发育为花瓣束.研究认为:舞花姜的唇瓣是一个三重结构,其中央维管束代表1枚外轮雄蕊,两侧维管束则分别代表2枚内轮雄蕊;舞花姜的2枚花瓣状退化雄蕊与唇瓣的中央一起构成外轮雄蕊,唯一1枚可育雄蕊和唇瓣的两侧同属内轮雄蕊.本研究结果支持姜科子房延长部形成的腺体属于子房上部心皮边缘的维管化附属物的观点.

Flower Vascular Anatomy of Globba racemosa

The flower vascular anatomy of Globba racemosa was observed and analysed.The fate of lost stamens and the property of labellum and epigynous glands were discussed.The results show that:(1)the vascular of pedice are scattered within the fundamental tissue of Globba racemosa.(2)There are an outer ring including several large bundles and a central region consisting of dispersed small bundles.The bundles of the outer ring move towards the ovarian wall.The dorsal bundles of the carpels(CDBs) and the parietal bundles(PDs) are both derived from the central region.The branches from CDBs and PDs from an irregular vascular plexus,Above the anastomosing plexus,the adaxial bundles of CDBs serve as the midrib traces of the two staminodes.The abaxial bundle of CDBs enter the middle of the labellum.The other branches from CDBs run uptowards in to the sepals.(3)The exclusive function androecium receives the inner branches of the adaxial bundle of PDs,as a midrib.The abaxial bundles of PDs supply two margins for the labellum.The other branches from PDs enter into the three petals.It is deduced that the labellum of Globba racemosa is a triple structure.The middle bundle of labellum stands for a stamen of outer whorl and the two margins of the labellum indicate two stamens of inner whorl.The two lateral staminodes and the middle of the labellum compose the outer whorl.The function androecium and the two margins of the labellum are the components of the inner whorl.The results supports that the epigynous glands in Zingiberaceae should be regarded as special vascularized developments from the carpellary margins above the ovary.