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紫草科微孔草属及其近缘属花粉形态的研究

宁建长, 席以珍, 张玉龙   

  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:1993-07-18 发布日期:1993-07-18
  • 通讯作者: 宁建长

Pollen Morphology of Microula Benth. and Allied Genera (Boraginaceae)

Ning Jian-chang, Xi Yi-zhen, Zhang Yu-long   

  • Received:1900-01-01 Revised:1900-01-01 Online:1993-07-18 Published:1993-07-18
  • Contact: Ning Jian-chang

摘要:

 本文用光学显微镜和扫描电镜观察了微孔草属(Microula Benth.)6组16种及其相关的3属6
种植物的花粉,并对微孔草属2种和齿缘草属(Eritrichium Schrad.)2种花粉做了花粉壁超微结构的
研究。微孔草属及其相关的3属花粉为哑铃形,花粉体积很小,最大的为12.18×7.13μm,最小的只
有6.36×3.36μm,具相间排列的三孔沟和三假沟。但他们在赤道部位的缢缩程度、萌发孔特征、表
面纹饰及超微结构有明显的不同。从花粉形态看,微孔草属较原始,且与锚刺果属(Actinocarya
Benth.)有较密切关系;齿缘草属具双内孔或单内孔且为异极,为进化类型。

关键词: 微孔草属, 花粉形态, 超微结构, 亲缘关系

Abstract:

 Pollen grains of 16 species of Microula Benth. and six species of three
 related genera were examined under LM and SEM, and four of them also under  TEM. Pollen grains of Microula and three related genera are dumb-bell-shaped, 3-colporate apertures alternate with three pseudocolpi. Pollen grains are very small,ranging from 12.18 x 7.13 μm to 6.36 x 3.66μm. In general, colpi with os are
wider and shorter, rhomboid, but sometimes they are equal to pseudocolpi in length. Colpus margins are regularly or irregularly tooth-like. The surface of colpi is psilate or processed. Ora are circular or lalongated in outline, protruded or not;  surface of os membrane is smooth or scabrid.  The exine is usually indistinctly layered under LM. The exine surface is psilate, and more or less perforate. TEM examination shows that the pollen wall is differentiated into exine and intine: the exine includes ectexine and endexine, while the ectexine consists of
tectum, columellae and foot-layer. However, there are differences in constriction of equatorial area, apertural characters, ornamentation and exinous ultrastructure between these genera.  Pollen morphology indicates that the genus Microula Benth. is primitive, directly related to the genus Actinocarya Benth .;  the genus Asperugo L. Is more advanced. The genus Eritrichium Schrad. which has two ora or one os and is anisopolar, represents the most advanced group among them. Noteworthily, the diorate phenomenon is found for the first time not only
in the genus but in the family Boraginaceae.

Key words: Microula Benth., Pollen morphology, Ultrastructure, Phylogeny