白豆杉的胚胎发育及其系统位置的商榷

中国科学院大学学报

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白豆杉的胚胎发育及其系统位置的商榷

陈祖铿, 王伏雄

(中国科学院植物研究所)

收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:1978-05-18 发布日期:1978-05-18
通讯作者: 陈祖铿

Embryogeny of Pseudotaxus chienii in relation to its systematic position

Chen Tsu-Keng, Wang Fu-Hsiung

(Institute of Botany, Academia Sinica)

Received:1900-01-01 Revised:1900-01-01 Online:1978-05-18 Published:1978-05-18
Contact: Chen Tsu-Keng

摘要/Abstract

摘要：

白豆杉属(Pseudotaxus Cheng)是我国裸子植物特有属之一，它的胚胎发育十分类似于红豆

杉属。白豆杉受精卵经4次有丝分裂，形成16个游离核的原胚，紧接着形成细胞壁。简单多

胚普遍存在，但没有裂生多胚。在后期胚胎发育中，根原始细胞主要向上分化形成原形成层和

胚皮层，向下提供根冠较少。因此，根冠组织弱小，而次生胚柄系统则十分发达。成熟胚具2

枚子叶，下胚轴中没有髓部，也没有任何分泌分子。

通过白豆杉胚胎发育的研究，作者认为白豆杉属在红豆杉科中的排列位置是：红豆杉属、

白豆杉属、澳洲红豆杉属、穗花杉属和榧树属。其中红豆杉属和白豆杉属比较原始，而榧树属

则比较进化。同时作者认为：从胚胎学资料看，将红豆杉科从松柏目中分离出来，单独成立红

豆杉目，这种观点得不到支持。

Abstract:

The embryogeny of Pseudotaxus chienii Cheng, a member of Taxaceae, has been

investigated. Pseudotaxus is endemic to China and its distribution is restricted to

Lung-chuan County, Chekiang, Ching-kang Mountains, Kiangsi and Sze-ming Moun-

tains, Kwangsi. The material used for the embryological study was collected in 1964

from Lung-chuan, the type locality of Pseudotaxus.

Fertilization took place within the last week of May, 1964. The fertilized egg

undergoes four mitotic divisions in succession without wall formation and a proem-

bryo of 16 free nuclei is formed. Then the wall formation follows. The 16 cells of

the proembryo are arranged in two groups, the upper one being the open tier (O)

and the lower, the primary embryo cells (PE). The relative number of cells (O :PE)

is usually 9:7, occasionally 10:6 or 8:8, rarely 7:9. The cells in the open tier are

often not walled above. The division of the open tier results in the formation of the

upper tier and the prosuspensor. While the prosuspensor cells begin to elongate the

divisions of the primary embryo cells give rise to the embryo cells (12-18 cells).

Usually two archegonia in the same ovule are fertilized and two embryonal sys-

tems are developed. Thus, simple polyembryony prevails. In addition, several su-

pernumerary embryonic masses may be found above the prosuspensor cells but they

are usually ephemeral because of lack of sufficient nutrients in later stage. Cleavage

polyembryony is absent in Pseudotaxus.

A cap cell is usually formed at the apex of the young embryo. In later stages

of embryonal development root initials contribute mainly to the procambium and

embryonic cortex but less to the root cap. The embryo matured about the middle

of September, 1964. The mature embryo has two cotyledons. No pith is formed in

the central cylinder. No secretory elements are developed in any part of the embryo.

The suspensor is well developed and becomes massive while the root cap is rather

weak. The similarities in the embryogeny between Pseudotaxus and Taxus are very

striking. They have a similarity in the development and general structure of the

proembryo; cleavage polyembryony is absent while simple polyembryony prevails;

both have no pith and no secretory elements in the mature embryo.

Based upon the results obtained from the present investigation in Pseudotaxus

the authors consider that the systematic position of Pseudotaxus in Taxaceae may be

arranged as follows: Taxus, Pseudotaxus, Austrotaxus, Amentotaxus and Torreya.

Among them Taxus and Pseudotaxus are relatively primitive and Torreya is the most

advanced, while Austrotaxus and Amentotaxus are between. The embryological data

do not support the viewpoint of Florin that Taxaceae should be removed from Coni-

ferales and a parallel order Taxales should be established.

陈祖铿, 王伏雄. 白豆杉的胚胎发育及其系统位置的商榷[J]. 中国科学院大学学报.

Chen Tsu-Keng, Wang Fu-Hsiung. Embryogeny of Pseudotaxus chienii in relation to its systematic position[J]. .

白豆杉的胚胎发育及其系统位置的商榷

Embryogeny of Pseudotaxus chienii in relation to its systematic position

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