黄花烟草大孢子发生、雌配子体及胚胎发育的研究

The Megasporogenesis and Development of Female Gametophyte and Embryo of Wild Nicotiana rustica L.

研究采用石蜡切片法对野生种黄花烟草大孢子的发生、雌配子体和胚胎的发育过程进行了研究,力求探明黄花烟草胚珠发生与雌配子体形成的过程,为进一步了解其遗传背景和指导今后烟草的栽培、培育新品种提供有关资料。结果表明,野生种黄花烟草的子房由2个心皮组成,具假隔膜,中央特立胎座,倒生多胚珠;大孢子母细胞进行减数分裂后形成的4个大孢子组成四分体呈一直线排列,合点端的大孢子继续发育成为功能大孢子然后继而成为单核胚囊;雌配子体的发育经由功能大孢子通过3次有丝分裂发育成为成熟的八核胚囊,胚囊发育为蓼型;胚胎发育为茄型,果实类型为蒴果;其大孢子发生、雌配子体和胚胎均正常发育。

The development of megasporogenesis, embryo sac and embryonic of wild Nicotiana rustica L. was analyzed by paraffin section, which provided genetic background information for this species and additionally guides the growth and breeding work of Nicotiana. The results showed that the ovary consists of two carpels, with pseudoseptum and free central placentation, the ovule was anatropous and many per locule, megasporocyte meiosis formed after 4 large spores in a straight line up a tetrad ar rangement, the megaspore of the chalazal part continued to develop into function megaspore and then become uninucleate embryo sac. The female gametophyte became mature eight-nuclear embryo sac through three times mitosises development of the function megaspore, the development of embryo sacwas polygonum type. Embryonic development was tomato type and type of fruit was capsule. The whole development process of N. rustica L. was normal.