星星草大、小孢子发生与雌、雄配子体发育的观察

Megasporogenesis,Microsporogenesis and the Development of the Female and Male Gametophyte of Puccinellia tenuiflora

利用常规石蜡制片法研究了星星草[Puccinelliatenuiflora(Griseb.)Scribn.etMerr.]大、小孢子发生及其雌、雄配子体的发育过程。主要结论是:(1)小孢子母细胞减数分裂过程中的胞质分裂为连续型,四分孢子为左右对称型;(2)成熟的花粉为三细胞型,具单萌发孔;(3)花药壁由4层结构组成,最外层为表皮,其内分别为药室内壁、中层、绒毡层,绒毡层为分泌型,花药壁的发育属于单子叶型;(4)星星草为单子房,单胚珠,双珠被,薄珠心,倒生型胚珠。大孢子母细胞经减数分裂形成线形排列的4个大孢子,合点端大孢子具功能;(5)胚囊发育属于蓼型,成熟胚囊形成时,反足细胞经无丝分裂形成4～6个反足细胞,反足细胞内可能存在多次DNA复制过程。

Megasporogenesis,microsporogenesis and the development of female gametophyte and male gametophyte of Puccinellia tenuiflora using normal paraffin method are studied in this paper. The main results are as follows: (1) The microspore mother cell undergoes meiosis before it turns into microspore tetrad. Its cytokinesis is successive type, and its tetrad is bilateral. (2) The mature pollen grains are three-celled, and each has a single germinal aperture. (3) The anther wall is composed of four layers, epidermis, endothecium, middle layer and tapetum respectively, and the tapetum is secretory type. The development of anther wall follows the monocotyledonous type. (4) Simple ovary, uniovulate, anatropous ovule and tenuinucellate nucellus. The megasporocyte divides into linear megaspore tetrad after meiosis. The chalazal end megaspore is functional. (5) The embryo sac is the Polygonum type. When the embryo sac is mature, the antipodal cells divide into four to six cells. There may be DNA duplication processes for many times within them.