狭叶柴胡大小孢子发生和雌雄配子体发育的研究

Megasporogenesis,microsporogenesis and development of male and female gametophytes in Bupleurum scorzonerifolium

关键词:  狭叶柴胡  大孢子发生  小孢子发生  雌配子体  雄配子体

Key words:  Bupleurum scorzonerifolium  megasporogenesis  microsporogenesis  male gametophyte  female gametophyte

摘要:

用石蜡切片法、半薄切片法对狭叶柴胡的大、小孢子发生和雌、雄配子体发育进行观察研究。结果显示:(1)狭叶柴胡花药壁的发育为双子叶型,腺质绒毡层; 小孢子母细胞减数分裂过程中的胞质分裂为同时型,四分孢子为正四面体形; 成熟的花粉粒为3-细胞型,具3个萌发孔。(2)倒生型胚珠,单珠被,薄珠心; 大孢子母细胞常为一个雌性孢原直接发育而成,大孢子四分体呈线型,多数情况为合点端一个大孢子分化为功能大孢子; 由功能大孢子发育为蓼型成熟胚囊。(3)八核胚囊时期,珠心基部和两侧的一些珠心细胞留存较久,成为珠心座细胞。此外,珠被内表皮细胞发育为珠被绒毡层。

Abstract:

Megasporogenesis,microsporogenesis and development of male and female gametophytes of Bupleurum scorzonerifolium were studied using method of paraffin section and semi-thin section. Firstly,the development of the anther wall belongs to a dicotyledonou's type. The tapetum was glandular. The cytoplasm of microspore mother cell undergoes simultaneous division and produces tetrahedral tetrad; the mature pollen is 3-cell type and has three colporates. Secondly,the ovary of B.scorzonerifolium is anatropous,single integument and thin nucellus. Usually one archesporium functions directly as a megaspore mother cell,in which cytokinesis usually accompanies meiosis,and mostly the chalaza megaspore of a linear tetrad develops into a Polygonum-type embryo sac. Thirdly,during 8-nuclei embryo sac stage,some nucellus on the base and two sides keep their own cytoplasm and shape for a long time and finally become podium. In addition,the inner integument cells developed into endothelium.