| 从胚胎发育看穗花杉属的系统位置 |
| |
| 引用本文： | 陈祖铿,王伏雄.从胚胎发育看穗花杉属的系统位置[J].中国科学院研究生院学报,1984,22(4):269-276. |
| |
| 作者姓名： | 陈祖铿 王伏雄 |
| |
| 作者单位： | (中国科学院植物研究所，北京) |
| |
| 摘 要： | 穗花杉 Amentotaxus argotaenia 胚胎发育的主要特点是： 原胚在16核时形成细胞壁， 幼胚发育缓慢，并要经过一个冬季低温阶段，一直到第二年种子脱落时，它们还处于简单多胚 的选择时期, 后期胚的发育是在种子脱离母树后进行的。根据胚胎发育特点，穗花杉属在红豆杉科中的系统位置(由原始到进化的顺序)是：穗花杉属，澳洲红豆杉属，红豆杉属，白豆杉属，榧树属。
|
| 关 键 词： | 穗花杉 胚胎发育 系统发育 |
On the Systematic Position of Amentotaxus from Its Embryological Investigation |
| |
| Chen Zu-Keng,Wang Fu-Hsiung.On the Systematic Position of Amentotaxus from Its Embryological Investigation[J].Journal of the Graduate School of the Chinese Academy of Sciences,1984,22(4):269-276. |
| |
| Authors: | Chen Zu-Keng Wang Fu-Hsiung |
| |
| Institution: | (Institute of Botany, Academia Sinica, Beijing) |
| |
| Abstract: | The present paper deals with the embryological study and the systematic
position of Amentotaxus argotaenia (Hance) Pilger. The material used was collected
during 1980-1981 from Jin-fo Shan, 1400-1600 m, Sichuan Province, China. The
species is dioecious. The male cone sheds its pollen during the period from the end of
May to the middle of June. The pollen at mature stage is 2-celled. Pollen chamber
appears obvious at the end of the nucellus. When pollen grains are dispersed, megas-
pore mother cell, which is situated deep in the nucellus, is in meiosis. The megaspore
divides mitotically after pollination and the free nuclei of female gametophyte divide
for the last time at the end of June. The wall formation takes place at the stage of 256
free nuclei. The development of archegonia takes place at the beginning of July and
the fertilization occurs about July 20-23. The fertilized egg divides successively
four times and results in a 16-nucleate proembryo. The young embryo is developing in
August. It is interesting to note that the development of the young embryo is very
slow. When the seed reaches the mature stage from June to July in the following
year, the multicellular masses of the young embryos resulted from simple polyembryony
remain immature within the female gametophyte. No cleavage polyembryony has been
found. The subsequent embryogeny takes place after the seed has shed.
Keng (1975) considers that Amentotaxus links the Taxaceae with Cephalotaxaceae.
Our embryological data support Keng’s conclusion since they share (1) compound
microstrobilus, (2) 2-celled pollen grains at shedding stage and (3) the rather long
life cycle. Keng (1975) also mentions that Podocarpaceae may connect with Taxaceae
through Phyllocladus. According to Keng the Podocarpaceae is related to Taxaceae to
certain degree. It is obvious that the primitive spike-like male strobilus like the one
in Cordaitales is obviously retained in Podocarpus spicatus and P. andinus of Podocar-
paceae and Amentotaxus of Taxaceae. In addition, like in Amentotaxus there are 16
nuclei before wall formation in the proembryo of Podocarpus nivalis. These facts may
well indicate that at least the Podocarpaceae and the Taxaceae were derived from a
common stock. As far as the Taxaceae is concerned the authors tend to support the
view of Koidzumi (1932) that Amentotaxus and Austrotaxus should be put in the same
tribe since both possess the spike-like strobilus, the long life cycle and the seed matura-
tion in the following year. They are probably rather primitive genera in the Taxaceae.
The proembryogeny of Torreya is more or less specialized. It may be placed in a ra-
ther advanced tribe and the tribe Taxeae (including Taxus and Pseudotaxus)may be
between the above two tribes. In conclusion, the Taxaceae is related to the Coniferales
in certain respects and, as Keng (1975), Harri (1976) and Wang et al. (1979) have
pointed out recently, placing of the Taxaceae in Coniferales is rather justifiable. |
| |
| Keywords: | Amentotaxus Embryogeny phylogeny |
|
| 点击此处可从《中国科学院研究生院学报》浏览原始摘要信息 |
| 点击此处可从《中国科学院研究生院学报》下载免费的PDF全文 |
|
