中国芸香科植物的花粉形态

本文用光学显微镜对我国21属52种2变种芸香科(Rutaceae)植物的花粉形态进行了详细地观察研究,其中对6属6种进行了扫描电镜观察。本科花粉具沟孔,是花粉单类型的科之一。根据萌发孔的数目和外壁纹饰特点,本文将芸香科的花粉分为具3孔沟和4-6孔沟两个花粉类型,并根据各属花粉形态特征,作出了花粉形态分属检索表。此外,本文还对花椒(Zanthoxylum L.)和Fagara两属的合并问题及花椒与吴茱萸(Evodia Scop.)两属之间的亲缘关系等问题进行了讨论。

POLLEN MORPHOLOGY OF THE FAMILY RUTACEAE IN CHINA

The pollen morphology of 52 species and 2 varieties belonging to 21 genera of Rutaceae from China was examined by means of light microscope of which 6 species examined by means of scanning electron microscope. The pollen of Rutaceae belongs to stenopalynous. According to numbere of the opertures and orn-amentation of exine the pollen of the family can be divided into two types:tricolporate and 4-6 colporate. A pollen morphology key has been shown in this paper based on the pollen characters. In addition, new conbination in Zanthoxylum and Fagara and close affinity between Zanthoxylum and Evodia were discussed in the present study The pollen grains of the family prolate-subspheroidal or ob-late,3-6 lobed-circular or subcircular in polar view. Polar axis×equatorial axis=(18.2-72.8)×(12.3-54.6). The smallest pollen are found in Zanthoxylum dimorphophyllum Hemsl., (20.0-25.0) 22.5×15.0(12.5-17.5). The lagest pollen grains are in Micromelum pubescens Bl.,(46.8-72.6)59.8×46.8 (39.0-54.6). Tricolporate pollen type is common in the family, but 4-6 colporate types are rarely found. The colpi are usually long and narrow with membrane The margin of some colpi are usually thickened.Some pollen are syncolpate in polar view, longicolpate with lalongate ora. The colpus and os intersect each other and They form a cross-mark in the equatorial view. Exine about 1.5-4.0 thick,sexine thicker than nexine. The columella layers are clearly visible. The ornamentations of exines are reticulate and striate. Based on numbers of the opertures and ornamentation of exine 21 genera can be divided into two types and four subtypes:1. Tricolporate (1) The tricolporate with reticulate ornametation; (2) Tricol porate with striate ornamentation. 2. 4-6 colporate (1) 4-6 colporate with reticulate ornamentation; (2) 4-6 colporate with striation ornamentation.