摘要
长喙毛茛泽泻Ranalisma rostratum Stapf小孢子母细胞的减数分裂过程为连续型,四分体为左右对称型。成熟花粉为三胞花粉。花药绒毡层为变形绒毡层。雌蕊由多数单室子房构成,每子房中含一具双珠被、薄珠心的倒生胚珠。胚囊发育为葱型。成熟胚囊中三个反足细胞退化;二个极核分别位于中央细胞的两端,其体积相差明显。这种极核分布可能与反足细胞过早退化有关。
Ranalisma rostratum Stapf is a rare and endangered species. This paper deals with the development of its male and female gametophytes and probes the relationship between the process of reproduction and the cause which made this species endangered. The meiosis of microspore mother cells is successive cytokinesis and the microspore tetrads are isobilateral. Pollen grains are 3-celled when shed. The ovule is anatropous, bitegmic and tenuinucellate. The micropylar dyad cell usually degenerates soon after its formation, and the chalazal dyad cell develops into a Allium type embryo sac. During the development of embryo sac both polar nuclei are respectively located at the two ends of central cell, and they maintain this situation until the micropylar polar nucleus takes part in fertilization. Features of the embryo sac of Ranalisma rostratum Stapf are discussed.
出处
《植物分类学报》
CSCD
1995年第3期221-224,共4页
Acta Phytotaxonomica Sinica
基金
国家自然科学基金委重大项目"中国主要濒危植物保护生物学研究"资助课题
项目编号39391500
