樟科植物花粉形态研究

樟科植物为我国南方常绿阔叶林重要组成成分，我国约有20属420余种。过去对于樟科花粉形态的研究仅限于在光学显微镜下进行观察记载，以台湾学者王仁礼的研究最为全面，共记载了台湾产14属40余种的花粉形态。本文作者以国产樟科为主，应用扫描电镜及光学显微镜对该科花粉形态进行了更为全面系统的研究，共观察记载了22属150余种，对各属的花粉形态特征均进行了描述；首次报道了樟科花粉有小穿孔的存在，并依据花粉的形状、外壁纹饰及小穿孔存在与否将樟科花粉划分为7个类型，即:1．厚壳桂型(Cryptocarya，Neocimamomum);2．檬果樟型(Caryodaphnopsis)；3．木姜子型(Litsea，Lindera，Neolitsea)；4．月桂型(Laurus)；5．鳄梨型(Persea，Machilus，Syndiclis，Nothaphoebe， Beilschemiedia，Phoebe，Alseodaphne，Octea)；6．檫木型(Sassafras，Cinnamomum，Umbellularia，Actinodaphne，Dehaasia)；7．无根藤型(Cassytha)。文中还讨论了樟科花粉的多样性、有关属之间的亲缘关系和分类问题以及同邻近的肉豆蔻科、莲叶桐科的关系。

POLLEN MORPHOLOGY OF THE FAMILY LAURACEAE IN CHINA

The plants of the family Lauraceae are main components of evergreen broad-leaved forests in southern China. There are about 20 genera 420 species of the family in Chi na. The authors of this paper made a comprehensive and systematic study on the pollen morphology of the family Lauraceae in China by means of light microscopy and scanning electron microscopy. The paper deals with 22 genera and more than 150 species and describes each genus. They can be distinguished according to the shape of pollen grains, sculpture of exine, existance of tenuity perforation. Based on the shape of pollen grains. they can be grouped into two types: spheroidal type, subspheroidal type. Because of lacking obvious aperture, it is rather difficult to distinguish their polar axis and equator. On the basis of the sculpture and structure of exine distinguished are seven pollen types; 1. Cryptocarya type, the exine smooth or scabrate, without spines: Cryptocarya, N eocinnamomum, etc. 2. Caryodaphnopsis type, the exine without spines, but with dense verrucae on the surface; only Caryodaphnopsis. 3. Litsea type, the exine with distinct spines, without mat-shaped thickening near the base of spines, usually with perforation or tenuity; Litsea, Lindera, Ne-olitsea, etc. 4. Laurus type, the exine with coarse triangular spines, with longitudinal streaks on the surface of spines, and with mat-shaped thickening near the base of spines; only Laurus. 5. Persea type, the exine with distinct spines and tenuity or perforation, usually the spines very small and dense, without mat-shaped thickening at the base of spines: Persea, Machilus, Phoebe, Nothapkoebe, Alseodaphne, Sydiclis and Octea. 6. Sassafras type, the exine with or without perforaion; spines smooth, with circular mat-shaped thickening at the base of spines: Sassafras, Dehaasia, Cinnamomum and Umbellularia etc. 7. Cassytha type, the exine smooth or scabrate, without spines, similar to Cryptocarga type but pollen grains very small: only Cassytha. The pollen morphology of the family Lauraceae was generally thought uniform, little variable and thus difficult to be distinguished. However, our study shows that the shape of pollen grains, the sculpture and structure of exine of the family are diverse. The present paper also discusses the evolutionary trend with taxo-nomic problems of these genera. Viewed from the pollen morphology, the family Lauraceae has a close relationship with the family Hernandiaceae and is similar to the family Myristi-caceae in some respects. Perhaps they are groups developed from the same ancestor. The existence of perforation in the family is reported for the first time.