大花铁线莲花芽分化及花器官发育特性

Flower Bud Differentiation and Flower Organ Development of Clematis patens

采用石蜡切片的方法对大花铁线莲(Clematis patens)的花芽分化及花器官发育特性进行系统的研究。结果表明:大花铁线莲的花芽分化时期可分为营养生长期、花芽分化初期、萼片原基分化期、雄蕊原基分化期、雌蕊原基分化期5个阶段。花芽分化始于4月下旬,5月中旬至6月上旬为花期;大花铁线莲的花药4室,花药壁由表皮、药室内壁、中层(1~2层)和绒毡层所组成。小孢子母细胞胞质分裂方式为连续型和同时型并存。小孢子四分体为左右对称型或四面体型,花粉为2-细胞型;大花铁线莲的子房1室,单珠被,倒生胚珠,大孢子四分体为直线型,其中合点端的大孢子发育为功能大孢子;胚囊为蓼型发育。

The flower bud differentiation and flower organ development characteristics of Clematis patens were systematically studied by paraffin section. The results are as follows: the bud differentiation of C. patens can be divided into five stages: vegetative growth stage, early flower bud differentiation stage, sepal primordial differentiation stage, stamen primordial differentiation stage, and pistil primordial differentiation stage. The bud differentiation of C. patens began in late April, and the main flowering period was from mid-May to early June. The anther wall was divided into four cells, and the anther wall consisted of the epidermis, the anther wall, the middle layer(1-2 layers), and the tapetum layer. Cytokinesis of microspore mother cells was continuous and coexisted. Microspore tetrads are bilateral or tetrahedral, and pollen was 2-cellular. The ovary consists of 1 carpel. The ovules are anatropous and it has single tepals. The megaspore tetrad was linear and the megaspore at the chalazal developed into functional megaspore. The embryo sac is developed in polygonum type.