亚洲茜草科粗叶木属及其相关属植物花粉形态研究

利用光学显微镜和扫描电镜研究了茜草科粗叶木属Lasianthus 16种2亚种、1变种及相关的5属5种的花粉形态。粗叶木属的花粉属于广孢型, 单粒。一般中等大小, 绝大多数为圆球形, 少数为近长球形或长球形。花粉形态特征, 特别是在萌发孔和外壁纹饰上表现出多样化。根据孔沟的数目或是否具有内孔, 可以将萌发孔分为(3-)4-(-5)孔沟和3孔。在所观察的这些种中, 萌发孔以3-4孔沟为主要类型, 比例为62.4%。外壁纹饰可分为细网状、粗网状和穴状。有部分种的花粉极面有穴状纹饰, 其余均为网状纹饰。网眼一般椭圆形、近圆形、三角形或者不规则形。少数外壁纹饰网脊上有颗粒状雕纹或模糊的颗粒, 网脊轮廓线呈波浪形, 一般凸出且平滑。大部分种的花粉具有沟膜, 沟膜上具有瘤状突起或小颗粒状, 沟边缘一般较平滑, 或粗糙, 有的种具有沟桥。

Pollen morphology of the genus Lasianthus (Rubiaceae) and related taxa from Asia

Pollen morphology of 16 Asian species including two subspecies and one variety of the genus La-sianthus and five species from five related genera was examined by light microscopy and scanning electron microscopy. Lasianthus Jack is eurypalynous. The pollen grains are small to medium in size and spheroidal or subprolate in shape, with a few being prolate. Pollen morphology is remarkably diverse, particularly in aperture and exine ornamentation. The apertures are usually (3-)4-(-5)-zonoaperturate, being porate and pororate. The number of apertures varies from three to five, with the majority of species being 3-4 zonoaperturate. The exine is usually perforate, finely reticulate or coarsely reticulate. Pollen data appear to be morphologically informative and useful for distinguishing among species of Lasianthus, and for elucidating the relationships among some species.