关苍术两性花与雌花花药的解剖学研究

Anatomical studies of hermaphrodite and female flower anther development of Actractycodes japonica

关键词:  关苍术, 花药发育, 聚药雄蕊, 退化雄蕊, 雄配子体

Key words:  Actractycodes japonica, anther development, synantherous stamen, staminodium, male gametophyte

摘要:

苍术属(Atractylodes DC.)是菊科菜蓟族(Cynareae)刺苞亚族(Carlininae O. Hoffm.)的一个东亚特有属,世界上仅有7 种,其中我国有5 种。该研究以关苍术为材料,采用石蜡切片法比较研究了两性花和雌花的花药及雄配子体发育进程,并进一步探讨了其雌花产生花药退化的时期及原因。结果表明:(1)关苍术小孢子发育与花蕾长度间存在相关性,当花蕾长度在5 mm时进入花粉母细胞时期,花药壁已分化,在7～9 mm时处于四分体时期,大于11 mm时开始进入花粉粒时期。(2)关苍术花药5 个,花粉囊4 个,减数分裂属同时型,四分体以正四面体为主,属3-细胞型,萌发沟3个。(3)关苍术花粉囊壁发育属双子叶型,从外层的表皮、药室内壁,到内层的中层和绒毡层均由一层细胞构成,关苍术绒毡层为腺质绒毡层。(4)关苍术雌花花药退化发生在花药发育早期至四分体时期,表现为花药发育早期畸形、药壁分化异常、小孢子母细胞发育停滞在前期、绒毡层增生4个原因。该研究结果为苍术属植物的系统发育、物种形成和进化提供胚胎学依据。

Abstract:

Atractylodes DC. is a special Carlininae O. Hoffm. of Cynareae in Northeast Asia. Among the only 7 varieties in the world there are 5 in our country. Anther development and the developing process of male gametophyte of Actractycodes japonica were studied by paraffin method, and the causes and occurrence period of the female flowers anther degradation were further studied. The results were as follows:(1)There was a relationship between microspore cytological development and bud length of actractycodes japonica. It entered into the pollen mother cells period when the bud length reached 5 mm and the anther wall had already been divided. Then it was tetrad stage when it reached 7-9 mm. And it turned into the pollen grain period when it was longer than 11mm.(2)There are five anthers in one flower and there are four pollen sacs in every anther. Meiotic division of microsporocyte developed synchronously and the arrangement of microspores in the tetrad was mainly tetrahedral and it had 3 germinal furrows.(3)The development of anther wall follows the dicotyledonous type was composed of four layers, namely epidermis, endothecium, middle layer and tapetum from outside to inside,which belonged to glandular type.(4)The female flowers anther degradation of A. japonica was due to four reasons which were anther early developmental malformation, medicine wall differentiation abnormality, the microspore mother cells stop in meiosis prophase and cannot enter into tetrad stage and tapetum hyperplasia. This study provides the embryological basis for the phylogeny, speciation and evolution of A. japonica.