摘要
单穗升麻的雌蕊群由 1～ 5枚离生心皮组成。子房单室 ,4～ 9枚倒生胚珠 ,双珠被 ,厚珠心 ;大孢子四分体呈线形或T形排列 ,合点端一个具功能。胚囊发育为蓼型。成熟胚囊中 3个单核反足细胞 ,胞质浓密 ,在球形胚时期尚能观察到其退化痕迹。极核融合早 ,次生核位于合点端。胚胎发生为柳叶菜型 ;核型胚乳。雄蕊凋谢后 1～ 2天花柱顶端腹缝线周围出现乳突细胞 ,雄蕊凋谢后 3～ 5天延长成柱头毛。讨论了单穗升麻与南川升麻柱头可授期与花粉生活力的差异对传粉效果和结籽率的显著影响。
This is one of a series of studies on the reproductive features in Cimicifuga nanchuanensis Hsiao, an endangered plant endemic to China, and C. simplex Wormsk, a closely related and widely spread species as a control. The present paper deals with the results of cyto morphological observations on the megasporogenesis, the development of female gametophytes, and the embryogeny in C. simplex. Its anatropous ovules are bitegminous and crassinucellate. A megaspore mother cell undergoes meiosis to form a linear or T shaped megaspore tetrad. The embryo sac is of Polygonum type. The three antipodal cells persist up to the globular stage of embryo development. Two polar nuclei fuse to form a secondary nucleus close to the chalazal end of the embryo sac and connect with antipodal cells before fertilization. The development of endosperm is of Nuclear type. Cellularization of nuclear endosperm initiates since early globular stage of the embryo development. Development of the embryo in C. simplex is of Onagrad type. C. simplex is dichogamous. Stigmatic papillae emerge on the 1st～2nd day and they elongate into stigmatic hairs on the 3rd～5th day after stamens withering. The great impact of the differences of the receptible period of stigmas and pollen viability between the two species on effective pollination and seed setting rate is discussed.
出处
《植物分类学报》
CSCD
2000年第4期337-342,共6页
Acta Phytotaxonomica Sinica
基金
国家自然科学基金重大项目!(No.3 93 91 50 0 )
关键词
单穗升麻
雌配子体发育
胚胎发生
柱头发育
Cimicifuga simplex Wormsk
Megasporogenesis
Female gametophyte development
Embryogeny
Stigma development
