牛膝菊大、小孢子发生和雌、雄配子体的发育

通过石蜡切片技术对牛膝菊大小孢子发生和雌雄配子体发育过程进行研究,结果表明,牛膝菊花药4室,花药壁发育为简化型。由表皮、药室内壁和绒毡层组成。绒毡层于小孢子四分体时期开始变形,其细胞原生质体向药室中移动为变形绒毡层。小孢子孢原为多细胞,小孢子母细胞减数分裂产生四面体型的小孢子四分体。四分体胞质分裂为连续型,偶见同时型。成熟花粉2-细胞型。子房1室,每室1个倒生胚珠,具单珠被,薄珠心。大孢子母细胞减数分裂形成的4个大孢子呈直线形排列,其中合点端的大孢子为功能大孢子,蓼型胚囊。

Study on Megasporogenesis, Microsporogenesis and Development of Female and Male Gametophytes in Galinsona parviflora Car.

This paper studies the megasporogensis,microsporogenisis and development of female and male ga- metophyte by paraffin wax of the meiosis of megaspore and microspore mother cells and the developmental processes of Galinsona parviflora Cav. 1 The results indicates that the anther has four chambers. The develop- ment of anther wall is primitive type which is composed of epidermis, endothecium and amoeboid tapetum. The tapetum begins to vary at the stage of tetrad with the cytoplasm moving into the anther cell. The cytokinesis of microspore mother cell in meiosis is simultaneous and continuous, and the tetrad are tetrahedral. The mature pollen grain is 2-celled. The ovary has 1 locule and there is l anatropous ovule in each locule. The ovule is unitegmic and tenuinucellatae. The megaspore mother cells are developed cal cell which undergoes meitotic division and forms a linear tetrad. The directly by a hypodermal archcspori- embryo sac is of Polygonum type.