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1.
通过扫描电镜观察了宽叶泽苔草Caldesia grandisSamuel.的花器官发生。宽叶泽苔草 的萼片3枚，逆时针螺旋向心发生 ；花瓣3枚，呈一轮近同时发生，未观察到花瓣_雄蕊复合原基；雄蕊、心皮原基皆轮状向心 发生，最先近同时发生的6枚原基全部发育成雄蕊，随后发生的6枚原基早期并无差别，在发 育过程中逐渐出现形态差异，直至其中1－4枚发育成心皮，其余的发育成雄蕊；而后的几轮 心皮原基，6枚一轮，陆续向心相间发生。本文揭示了3枚萼片螺旋状的发生方式，并推测这种螺旋方式是泽泻科植物进化过程中保留下来 相似文献
2.
运用扫描电镜观察了眼子菜的花器官发生过程。结果表明：花原基从花序轴的基部开始以三数
交互轮状的方式发生,在花原基发生的早期具有明显的苞片原基形成。花器官是以向心的方式发生的, 二枚侧方花被片原基首先形成,紧接着产生二枚中间花被片。四枚雄蕊分两轮分别在与侧方花被和中 间花被相对的位置发生,四枚雄蕊原基在发生时均呈长条形。上述四轮花被和雄蕊虽然在时间上以二 数轮状的方式发生,但在空间上花被片和雄蕊各自分别排成一轮。最后,二个心皮原基在花原基顶端略 偏于一侧并与雄蕊相间的位置同时发生。有些花的二枚心皮原基发生后其中一枚很早即停止生长或仅 有一枚心皮原基形成。本文结果支持了眼子菜属心皮数目逐渐向简化的方向演化的观点。在花原基早期发育的过程中苞片原基的存在表明眼子菜属植物成熟花中缺乏苞片是简化的结果。 相似文献
3.
运用扫描电镜和石蜡切片方法对非洲商陆Phytolacca dodecandra L′Her.的花器官发生过程及花器官各部分的位置排列进行了观察。结果表明：非洲商陆萼片5枚，以螺旋向心方式发生；没有观察到花瓣原基的发生；雄蕊为螺旋离心方式发生，前4枚雄蕊分2对出现在对萼位置，但此后发生的雄蕊的发生顺序明显区别于其他种；心皮4-5枚，与内部雄蕊互生。本文探讨了时空因素对花器官发生的影响，基于对非洲商陆花器官发生的观察，否定了“商陆属源于二轮雄蕊样式”的假说，并为商陆属中“五基数花起源于三基数花”的观点提供了新的证据。 相似文献
4.
本文用扫描电镜观察了泽苔草的花器官发生过程，观察结果表明：花萼以螺旋状方式向心发生，花瓣以接近轮状方式近同时发生，不存在花瓣雄蕊复合原基。雄蕊和心皮均以轮状向心方式发生，6枚雄蕊分两轮分别在对萼和对瓣的位置先后发生，至发育的后期排成一轮，但仍分别处于对萼和对瓣的位置；随后发生的第一轮3个心皮原基与3枚萼片相对，第二、三轮心皮原基分别为1~3个，与前一轮心皮相间排列向心发生。本文首次揭示了泽苔草花被的外轮3个萼片螺旋状发生方式，这种螺旋状方式很可能是泽泻科植物的花部结构在进化过程中适应环境而保留下来的一种较原始的叶性特征。 相似文献
5.
为进一步研究商陆科的系统位置提供花器官发生和发育的证据，在扫描电子显微镜下观察了商陆Phytolacca acinosa、多雄蕊商陆P. polyandra和垂序商陆P. americana的花器官发生。结果表明： 商陆属植物花被的发生均为2/5型螺旋发生。在同一个种不同的花蕾中，花被的发生有两种顺序：逆时针方向和顺时针方向。远轴侧非正中位的1枚先发生。雄蕊发生于环状分生组织。在单轮雄蕊的种中8-10枚雄蕊为近同时发生；两轮雄蕊的种8枚内轮雄蕊先发生，6-8枚外轮雄蕊随后发生，内轮雄蕊为同时发生，外轮雄蕊发生次序不规则。心皮原基也发生于环状分生组织，8-10枚心皮原基为同时发生。在后来的发育过程中，商陆的心皮发育成近离生心皮雌蕊；其他2种心皮侧壁联合发育成合生心皮雌蕊。对商陆属植物花器官发生的类型及发育形态学做了分析，结果支持商陆科在石竹目系统发育中处于原始地位的观点。 相似文献
6.
在扫描电镜下观察了马桑绣球Hydrangea aspera孕性花的发生及发育过程。马桑绣球的花器官向心轮状发生：花萼原基以2/5螺旋式相继发生，花瓣原基几乎同步发生。花瓣开始发育时，与花萼相对的雄蕊发生。与花瓣相对的雄蕊原基与心皮原基几乎同时出现。初始心皮向上扩展，分化出花柱和柱头，向下延伸，嵌入花托，发育为下位子房。花发育成熟时，隔膜于子房的下部连续，而中部和上部不连续，即子房为不完全2室。经过与绣球属已观察过的另外5种1亚种花器官发生和发育比较，发现马桑绣球与藤绣球H. ano mala subs 相似文献
7.
通过扫描电镜对澜沧荛花Wikstroemia delavayi花部的形态发生过程进行了观察和分析，旨在为该属的系统学研究提供花部发育形态学资料。澜沧尧花花部的发生和早期发育呈远轴面向近轴面的顺序，但这一式样由于近轴面的器官在早期发育之后生长加速发生了转变。因此，花开放时所表现的所谓辐射对称，显然是由同一轮器官的异率生长所导致的次生现象。花盘发生于花萼筒基部的远轴面上，与花萼、雄蕊的发生间隔时间较长。花盘原基在下轮雄蕊着生处凹陷或间断，与之相对应，花盘裂片与下轮雄蕊呈互生。由此，花盘显然不是花托的一部分，也不是象花萼、雄蕊和心皮一样的独立结构，将其解释为雄蕊群的一部分更合理。花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性，这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有—定意义。根据对雌蕊群的发生和发育过程观察，该种的子房是由一个近轴面的可育心皮和一个远轴面的不育心皮融合而成的单室子房，为假单心皮雌蕊。尽管荛花属和瑞香属均属于单室产房，但澜沧荛花的子房维管束中的腹束排列于中轴位置，而目前资料显示瑞香属植物的腹束接近于侧膜位置，这方面仍需进一步研究。 相似文献
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9.
在本文中描述了乌头属和翠雀属各一新种和一新亚种，唐松草属一新种，侧金盏花属一新亚种，以及毛茛属五新种，首次报道了圆叶唐松草在中国西藏南部的分布,在对叶、雄蕊和心皮的形态特征进行了分析之后认为，这种植物与特产云南的糙叶唐松草有一定亲缘关系。 相似文献
10.
论平当树属的系统位置 总被引：2，自引：0，他引：2
唐亚 《中国科学院研究生院学报》1993,31(4):297-308
在现代植物分类系统中，平当树属被归入梧桐科或木棉科，其正确的系统位置至今没有定
论。本文从外部形态，幼苗形态、脉系，叶和木材及种皮解剖，花粉形态及染色体数目等诸方面对
该属进行了研究。 在平当树属中，花排列成聚伞花序，果成熟时花被宿存；雄蕊15，5束，与5枚退化
雄蕊结合成雄蕊筒，花药2室；子叶2裂；等面叶，中脉维管束2，弓形，叶柄维管束2，圆形；气孔
器限于下表皮，不等细胞型或稀短平列型；外种皮5—6层细胞厚：内种皮3—4层细胞厚；导管分
子弦向直径54—83μm,长270—423μm,复管孔常由10—20个管孔组成，排列成显著的径列管孔
链，管孔很多，轴向薄壁组织极少，射线单列或2—3列，异型；花粉粒具3孔，球形，外壁具刺；
体细胞染色体2n=20，核仁在有丝分裂前期消失。根据上述特征及其与梧桐科和木棉科的比较，作者认为平当树属应该属于梧桐科的Dombeyeae族，不宜移至木棉科。 相似文献
11.
本文通过对三白草科 saururaceae 裸蒴属 Gymnotheca Decne． 营养器官的解剖和观察，发现该属和三白草属Saururus L.、蕺草属 Houttuynia Thunb. 有明显的区别，而同胡椒科Piperaceae 的齐头绒属 Zippelia Bi．则有许多相似的特征。因此我们认为该属和齐头绒属同为三白草科和胡椒科的中间过渡类型。 相似文献
12.
中国毛茛科植物小志(廿二) 总被引：2，自引：0，他引：2
王文采 《中国科学院研究生院学报》1998,36(2):150-172
(1)揭示了铁线莲属以下演化趋势:萼片由开展到直立;雄蕊由无毛到有毛;雄蕊花丝由条形演
化到披针状条形或倒披针状条形;花药由长圆形演化到条形或狭条形;药隔不突出到在顶端突出;在雄
蕊被毛时,毛由少而短到多而长;此外花序由具花序梗和苞片到花序梗和苞片消失,以及由自当年生枝
叶腋生出转变到自老枝腋芽中生出。主要根据上述演化趋势,本文将我国铁线莲属各组及组下分类群做出新的排列。(2)描述了6新亚组,6新系,2新种,4新变种,给出了5新组合,4新等级和2新名。 相似文献
13.
14.
猕猴桃科的花粉形态及其系统位置的探讨 总被引：3，自引：0，他引：3
张芝玉 《中国科学院研究生院学报》1987,25(1):9-23
本文作者用光学显微镜和扫描电镜(少数种类用透射电镜)对猕猴桃科Actinidia-
ceae(按照Cronquist 1981和Dahlgren 1983的概念)的猕猴桃属Actinidia(15种)、藤山柳
属Clematoclethra(5种)和水东哥属Saurauia(3种)植物的花粉形态进行了观察，并与山茶科
Theaceae(7属9种)和山柳科Clethraceae(1属1种)的花粉进行了对比分析。根据花粉的
资料，并综合分析有关的外部形态、胚胎和化学方面的特征，讨论了猕猴桃科的范围，以及这个
科的系统位置。 相似文献
15.
陈心启 《中国科学院研究生院学报》1965,10(3):193-206
Tangtsinia* S. C. Chen, a monotypic genus, is discovered in southeastern Szechuan
in China. It possesses a rather ordinary monocotyledonous habit, namely with a short
rhizome, non-thickend annual stem with scattered, spiral-arranged leaves and a terminal
inflorescence. Its habit somewhat similar to that of some very primitive genera, viz.
Apostasia, Tropidia, Cephalanthera and Selenipedilum, is of much morphological and
phylogenetic interest.
The primitive and significant floral features consist chiefly in the erect, hardly twisted
flower with nearly regular perianth and a unilocular ovary, in the column composed of
a terminal stigma and five small projections, in an erect anther with four naked pollinia,
and in the absence of the rostellum. Of special interest is the occurrence of five small
projections in the upper part of the column, and this is, however, a unique instance in
the family, including the Apostasieae. Among the five projections three are larger and
opposite to the petals respectively. Of these the two lateral ones bear a strong resem-
blance in texture to the two auricles in the Orchideae and some members of the Limo-
dorinae, which P. Vermeulen considered not as staminodia, but as appendages of the
single fertile stamen as usually seen in Allium. In the case of Tangtsinia, there exists the
third projection which, being situated in the front of the column and thus opposite to the
median petal (lip), shows no difference both in appearance and texture from the other
two. These three projections are at equal distance around the terminal stigma. In
view of these facts they can be no other organ than staminodia, representing the three
stamens of the inner whorl. And the other two smaller projections are also staminodia
which together with the single fertile stamen represent the outer whorl of three stamens.
Now it is safe to say that the two auricles existing in Cephalanthera, Epipactis and the
Orchideae are, in fact, also staminodia, representing the two lateral stamens of the in-
ner whorl. In consequence, there is fairly good reason to believe that the column in
Orchidaceae has developed from the union of six stamens and a central style, and this
is in agreement with the conclusion drawn by Swamy from vascular anatomy of orchid
flowers. Furthermore it is also an interesting fact that the pollen grains in this genus,
like those of Cephalanthera, Pogonia (sensu stricto), Aphyllorchis and some species of
the Vanillinae, are single, while in the vast majority of the Orchidoideae they are united
into tetrads. This feature, as well as the texture of pollen grains, is of considerable
significance in the classification and phylogeny of Orchidaceae.
On the basis of its morphological characters mentioned above, the present genus is
evidently one of the most primitive types in the subfamily Orchidoideae. It bears a
strong resemblance both in habit and floral features to Cephalanthera, especially C. falcata
(Thunb.) Bl. The relationship between these two genera is apparently much closer to each
other than to any of other existing primitive orchids. In addition, the similarity in some
of significant floral characters between Tangtsinia and the saprophytic Aphyllorchis, especi-
ally in the nearly regular perianth and a subterminal stigma of A. simplex Tang et
Wang, indicates their close relationship. It is quite possible that Cephalanthera and
Aphyllorchis are derived from Tangtsinia or Tangtsinia-like ancestor. Thus, Tangtsinia
is here placed as the most primitive genus in the Limodorinae. Furthermore this new
genus likewise shows more or less close affinity to Neottia, probably through N. gaudis-
sarti Hand.-Mzt., in which the flowers consist of nearly regular perianth and a very
primitive column with a terminal stigma and without the rostellum. On the other hand,
in comparing Tangtsinia with the Apostasieae, there occurs also some similarity, but a
closer investigation of their ovaries, perianthes, stigmas and some other features indicates
that there is little evidence of close or direct relationship between these two taxa, al-
though both are the ancestral types in this large family. The probable relationships be-
tween Tangtsinia and its allies may be diagrammed as follows:
With regard to the pollination, Tangiorchis is found to be self-pollinated. In the great
majority of cases, its flowers do not open at all, and none of which has been seen to be
visited by any insects. It is interesting to note that in almost all nearly faded flowers
examined by the writer the bases of the pollinia together with the base of the anther have
become attached to the stigma of the same flower, and thus self-pollination has taken
place. This type of pollination might be comparable with that of Cephalanthera dama-
sonia Druce.
Finally the writer should say something about its geographical distribution. This mo-
notypic genus is confined to Gin-fu-shan (Mt. Gin-fu) and its adjacent region in Nan-
chuan District of southeastern Szechuan, where it occurs at scattered points within an area
of no more than 250 square km. at an altitude between 700-2100 m. In view of its mor-
phology, pollination and geographical distribution, Tangtsinia might be an ancestral relic of
the family Orchidaceae and would give a possible clue as to the origin of this complicatedfamily. 相似文献
16.