作 者 ：CHEN Xiao-Lin, LI Ming, YOU Rui-Lin
期 刊 ：植物分类学报 2000年 4期
关键词：单穗升麻大孢子发生雌配子体发育胚胎发生柱头发育；
Keywords:Cimicifuga simplex Wormsk, Megasporogenesis, Female gametophyte development, Embryogeny, Stigma deveolopment,
Abstract:
This is one of a series of studies on the reproductive features in Cimicifuga nanchuanen-
sis 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.