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1.
用扫描电子显微镜对国产 1 4种蜘蛛抱蛋属植物的花粉形态进行了观察 ,该属植物的花粉形态有长球形和球形 2种 ;外壁纹饰可分为 3大类型 :( 1 )皱波状纹饰 ;( 2 )小芽孢状纹饰 ;( 3)瘤棒状纹饰。它们的演化趋势是 :皱波状纹饰→芽孢状纹饰→瘤棒状纹饰  相似文献   

2.
羊蹄甲属中国特有种的花粉形态学   总被引:1,自引:0,他引:1  
对羊蹄甲属植物11种中国特有种的花粉形态进行了研究。结果表明,花粉萌发孔类型均为三孔沟,少数还有合沟;花粉均具半覆盖层,表面纹饰有皱波状、皱波状-穿孔、疣状、孔穴-穿孔、穿孔-网状。依据Larsen(1975)的划分,这11种植物的花粉隶属于Integrifolia型、Glauca型和Curtisii型,我们根据花粉纹饰的差异在Integrifolia型下进一步划分了Auma亚型和Paucinervata亚型。  相似文献   

3.
首次报道了兰科的手参属Gymnadenia国产5种植物花粉形态的研究结果,并与邻近的兜被兰属Neottianthe花粉进行了对比研究。前者花上块形状大多不规则,少数为三棱体形;而后者花粉小块大多形状为三棱锥体形,少数形状不规则。手参属花粉外壁表面具很细微的小穿孔、皱波状,小穴和小穿孔与沟渠状纹饰共存,或沟渠状等。而兜被兰属外壁表面纹饰明显,具有5种类型:(1)小穿孔,(2)表面近光滑,(3)沟渠状  相似文献   

4.
手参属花粉形态及其分类学意义   总被引:2,自引:0,他引:2  
首次报道了兰科的手参属Gymnadenia国产5种植物花粉形态的研究结果,并与邻近的兜被兰属 Neottianthem 花粉进行了对比研究。前者花粉小块形状大多不规则,少数为三棱锥体形;而后者花粉小块大多形状为三棱锥体形,少数形状不规则。手参属花粉外壁表面具很细微的小穿孔、皱波状,小穴和小穿孔与沟渠状纹饰共存,或沟渠状等;而兜被兰属外壁表面纹饰明显,具有5种类型: (1)小穿孔,(2)表面近光滑,(3)沟渠状,(4)拟网状,(5)典型的网状纹饰。手参属花粉表面具粘丝,而兜被兰属花粉表面没有发现粘丝。此外,本文还探讨了手参属和兜被兰属两属花粉在分类学上的意义。  相似文献   

5.
国产省藤属植物的花粉形态学   总被引:2,自引:1,他引:1  
对国产棕榈科省藤属(Calamius L.)15种植物的花粉进行了光学和扫描电镜观察,其中12种为首次报道。省藤属的花粉均为两沟型花粉,外壁覆盖层多为网状纹饰(大喙省藤C.macrorrhynchus)或具穿孔(华南省藤C.rhabdocladus)。首次发现省藤属花粉的外壁纹饰存在穿孔和外壁疣状突起的类型(阔叶鸡藤C.pulchellus)以及皱波状突起的类型(长鞭省藤C.flagellum)。花粉的大小、形状、外壁纹饰、外壁是否有突起,外壁厚度和网状纹饰网眼的大小,对于省藤属的种级分类有较大的意义。  相似文献   

6.
利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察了美乐多(Melodorum fruticosum)的花粉形态特征。美乐多花粉为球形或扁圆形的单粒花粉,外壁纹饰为微褶皱状,有点状凹陷,无任何萌发孔或萌发沟。花粉外壁由外壁外层包括覆盖层(连续)、覆盖下层、基足层(1~3层薄片层结构,偶断裂或扭曲至6~10层)和外壁内层(连续)组成。其中,覆盖下层,其厚度为整个花粉外壁厚度的1/2,为混合型结构,即小柱状和颗粒状同时存在,但以颗粒状为主。花粉内壁分为内壁外层和内壁内层,其厚度逐渐变薄。美乐多的花粉特征(单粒、无萌发孔或沟、覆盖层连续、基足层为薄片层结构、花粉外壁内层薄等)与紫玉盘族其他类群一致。  相似文献   

7.
单性木兰花粉壁超微结构的研究   总被引:6,自引:0,他引:6  
本文首次报道单性木兰花粉的形态特征和外壁超微结构。花粉外部形态与木兰科各属特征一致,表明单性木兰花粉的原始性。但花粉外壁超微结构显示其外壁表面具皱波状纹饰;覆盖层波浪状,具稀疏的小穿孔;柱状层很薄,小柱典型,直立,短而细。外壁超微结构表明单性木兰属在木兰亚族中是一个较进化的属。扫描电镜和透射电镜资料揭示出单性木兰在植物分类系统中的特殊地位和重要学术价值。  相似文献   

8.
3种番荔枝科植物花粉形态观察   总被引:1,自引:0,他引:1  
利用扫描电子显微镜对番荔枝科2属3种植物的干花粉形态进行了观察,旨在为番荔枝科植物花粉多样性及其演化关系提供形态学证据。观察结果显示,Asimina longifolia var.spatulata Kral、Asimina reticulate Shuttlew.ex Chapm.和Disepalum plagioneurum(Diels)D.M.Johnson 3种植物的花粉多为四合体,在Asimina reticulata内偶见二合体、三合体,Disepalum plagioneurum偶见多合体;四合体类型大多为偏菱形,A.reticulata和D.plagioneurum中偶见四角形;3种植物花粉表面纹饰分别为皱波状(rugulate)、微网状(microreticulate)和网状(reticulate)。花粉通过形成外壁短链接(short exine connections)或花粉联丝(pollen-connecting threads)的方式将四合体凝集成花粉块(pollinium),提高了单一传粉过程中卵细胞的受精几率。Asimina和Disepalum两属植物花粉在表面纹饰、四合体类型等方面都十分相似,支持两者在系统发育中亲缘关系较近的观点。  相似文献   

9.
中国紫金牛属圆齿组花粉形态研究及其分类学意义   总被引:2,自引:0,他引:2  
张巧玲  王少平  胡启明  郝刚   《广西植物》2007,27(3):385-392
利用扫描电子显微镜对紫金牛属圆齿组20种1变种植物的花粉形态进行了研究,并比较分析了腋序组2种及锯齿组1种的花粉。经观察花粉为近球形或近扁球形,具3孔沟,除锯齿组的月月红外,其余种均形成合沟。外壁纹饰可分为四类:穴网状、细网状、皱波状及细颗粒状(带刺突)。结果显示,花粉形态特征可作为属下分组及组下分类处理的依据。  相似文献   

10.
对栎属青冈亚属17个种及炭栎花粉形态进行扫描电镜观察。结果表明:青冈亚属和炭栎花粉均为三拟孔沟,球形至长球形,(15~28.0)μm×(15.0~25.6)μm。花粉外壁纹饰可划分为3种:(1)蠕虫状(包括皱波状)、(2)聚合颗粒状、(3)棒状或小刺状。各纹饰在组间镶嵌分布。棒状及小刺状纹饰为栎属花粉较为原始式样,并为青冈亚属与高山栎组及部分巴东组(sect.Cerris)共有,推测其间具有较其它栎类更为接近的亲缘关系,可能为广义栎属中较为基础的类群,而与栎亚属sect.Quercuss.s.,Lobatae和Protobalanus关系较远。花粉形态对广义栎属系统分类价值仅适用于较高分类阶元。  相似文献   

11.
The structure of the pollen of 42 species of Pseuduvaria (Annonaceae) is described. The pollen is consistently inaperturate, isopolar and radially symmetrical. Four basic patterns of exine sculpturing are identified: rugulate, verrucate, scabrate and psilate. The exine stratification of one representative species, P. macrocarpa , is shown to be entirely ectexinal. The ectexine consists of a discontinuous outer tectal layer, a columellar infratectal layer, and an inner lamellar foliated foot layer; the intine is very thin and fibrillar. The pollen is invariably released as acalymmate tetrads, in which the tectum is absent from the proximal walls. The individual pollen grains within the tetrads are connected by crosswall cohesion, involving both exine and intine; this form of cohesion has not hitherto been reported in the Annonaceae. In addition, pollen grains of neighbouring tetrads are connected in two different ways, viz. short exine connections and non-sporopollenin pollen-connecting threads. Neither of these cohesion mechanisms has previously been reported for the genus. The function of the various forms of cohesion between pollen grains and tetrads in Pseuduvaria is discussed as a mechanism to enhance the efficiency of pollination by enabling the fertilization of multiple ovules following a single pollinator visit.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 69−78.  相似文献   

12.
The morphology and ultrastructure of fresh pollen from nine species, one including two varieties representing seven genera of Annonaceae are described based on observations with scanning and transmission electron microscopy. The pollen grains are elliptic with a single furrow, or disulculate. Some are globose with no visible aperture or any indication of a pole. Ornamentation is smooth, rugulate, echinate or verrucate. The tectum is usually continuous and of the same thickness over the whole grain except for the aperture zone, where the exine elements are very often imperceptible. The infratectum may be granular, or columellae and granules are mixed together. The foot layer consists of continuous or irregularly contorted foliations. The endexine is distinct and thin, and varies slightly in thickness in some species, but is vaguely distinguishable in others. The intine is two-layered and consists of an entexine with many vesicular-fibrillar components with tubular extensions, and a more homogeneous endintine. The controversy around the presence of an endexine in Annonaceae is discussed, but whether its presence is ancestral cannot be determined. Data on fresh pollen are compared with those from similar studies on dried pollen.  相似文献   

13.
本文利用光镜及扫描电镜对湖北省泽泻科、水鳖科、眼子菜科及茨藻科11属29种1变种1变型植物(另加采于湛江的软骨草)的花粉形态进行了研究,发现泽泻科植物花粉具多个圆形萌发孔,外壁表面为小刺状纹饰;茨藻科植物花粉具远极单槽,表面为绉波状纹饰;眼子菜科及本文研究的水鳖科植物花粉均无萌发孔,分别具网状和小刺状饰纹饰。1.茨藻科植物花粉最原始,泽泻科花粉较进化,眼子菜科花粉较水鳖科花粉进化;2.泽泻属与泽苔草属花粉较慈姑属花粉原始;3.鞘叶眼子菜亚屈花粉较眼子菜亚属的花粉处于更高演化阶段;4.多孔茨藻花粉在该科中最原始。本文工作尚对易变形水生植物花粉形态研究方法进行了尝试。  相似文献   

14.
杉科植物花粉形态的研究   总被引:8,自引:0,他引:8  
席以珍 《植物研究》1986,6(3):127-144
杉科(Taxodiaceac)是裸子植物的重要科之一。全科共有10属16种。本文用光学显微镜和扫描电镜观察了本科7属10种植物花粉,并用透射电镜研究了其中5个属代表种的外壁内部的超微结构。  相似文献   

15.
Pollen grains of 107 species of 61 genera of the Gardeniinae were investigated by scanning electron and light microscopy. The subtribe is europalynous and grains occur either as monads, tetrads or massulae. Grains are porate, colporate or rarely pororate. The majority of the genera has 3-zonoaperturate pollen grains. However, deviating numbers of apertures occur in Byrsophyllum (4–8) and Pseudomantalania (4–5). Pantoporate pollen occurs in Randia . The average equatorial size (E) of monads varies between 13 μm in Anomanthodiu to 59 μm in Posoqueria . The tetrads vary from 37 μm in Casasia to 61 μm in Calochone and Euclinia . The exine is usually reticulate, but also foveolate, rugulate, perforate and psilate exine occurs in the subtribe. The thickness of the exine is only 0.3 μm in tetrad grains of Randia armata and in the pantoporate monad grains of R. ruiziana , whereas the thickest exine occurs in Posoqueria (2.8 pm) and Euclinia (2.9 μm). Tectal excrescenses are generally absent. However, three genera with pollen in tetrads, namely Euclinia, Gardenia and Oligoco-don , show this feature. Contrary to the subtribe most genera are fairly stenopalynous, but in the neotropical genera Alibertia and Randia several different types of pollen are encountered.  相似文献   

16.
本文报道了国产李亚科(Prunoideae)10属11种植物花粉形态。花粉近球形至长球形,极轴 20.00-44.12um,赤道轴门17.85-36.95um。极面观三裂圆形,赤道面观椭圆形至圆形。具三孔沟,内孔常为长方形。沟较长,两端较窄。但在 Sinoplagiospermum uniflora中除了3孔沟外,还有周孔沟。花粉外壁明显分化为覆盖层和柱状层,在光学显微镜下表面常模糊,扫描电镜下外壁纹饰均为条纹状。抱粉学结合形态学和细胞学证据说明本亚科为一单系发生的类群。Prinsepia utilis 和Sinoplagiospermum uniflora(Prinsepia uniflora)这两个种在花粉特征和外壁纹饰上差异很大,从而支持将 Prinsepia和 Sinopmplagiospermum分别处理为两个属但不支持将广义的Princepia(含Princepia和Sinoplagiospermum)独立为亚科。此外,由于Exochorda的外壁纹饰同Prunoideae中较原始的类群(如 Laurocerasus)相近,结合细胞学和形态学证据,支持将 Exochord移置至Prunoidea之下。  相似文献   

17.
东北杜鹃花科4属植物花粉形态的研究   总被引:4,自引:0,他引:4  
利用光学显微镜和扫描电子显微镜对东北杜鹃花科甸杜属(Chamaedaphne Moench.)、杜香属(Ledum Linn.)、松毛翠属(Phyllodoce Salisb.)、越橘属(Vaccinium Linn.)4属6种, 1变种的花粉形态进行了观察和比较研究。以上4属花粉粒均为四合花粉。四合花粉呈正四面体排列。花粉粒近球形。每粒花粉均具3沟,在四合花粉粒上,相邻花粉粒上的沟相接,有些种可见沟内的萌发孔。光镜下可见花粉外壁为内外两层,厚度约相等。不同属种的花粉粒在大小上有区别,花粉粒平均直径为34.0~43.7μm。在扫描电镜下观察可见不同的种花粉表面具有不同的纹饰。为分类学提供了孢粉学方面的证据。  相似文献   

18.
Brasenia is a monotypic genus sporadically distributed throughout the Americas, Asia, Australia, and Africa. It is one of eight genera that comprise the two families of Nymphaeales, or water lilies: Cabombaceae (Brasenia, Cabomba) and Nymphaeaceae (Victoria, Euryale, Nymphaea, Ondinea, Barclaya, Nuphar). Evidence from a range of studies indicates that Nymphaeales are among the most primitive angiosperms. Despite their phylogenetic utility, pollen developmental characters are not well known in Brasenia. This paper is the first to describe the complete pollen developmental sequence in Brasenia schreberi. Anthers at the microspore mother cell, tetrad, free microspore, and mature pollen grain stages were studied using combined scanning electron, transmission electron, and light microscopy. Both tetragonal and decussate tetrads have been identified in Brasenia, indicating successive microsporogenesis. The exine is tectate-columellate. The tetrad stage proceeds rapidly, and the infratectal columellae are the first exine elements to form. Development of the tectum and the foot layer is initiated later during the tetrad stage, with the tectum forming discontinuously. The endexine lamellae form during the free microspore stage, and their development varies in the apertural and non-apertural regions of the pollen wall. Degradation of the secretory tapetum also occurs during the free microspore stage. Unlike other water lilies, Brasenia is wind-pollinated, and several pollen characters appear to be correlated with this pollination syndrome. The adaptive significance of these characters, in contrast to those of the fly-pollinated genus Cabomba, has been considered. Brasenia does not produce pollenkitt nor develop tectal microchannels as does Cabomba. Instead, the discontinuity of the tectum reduces the amount of sporopollenin in the wall, which may allow for more effective wind dispersal. The importance of reassessing palynological characters in light of new ontogenetic data and the phylogenetic implications of this reevaluation are also discussed.  相似文献   

19.
The tribe Convallarieae (sensu Krause 1930) consists of 7 genera, i.e. Convallaria, Speirantha, Reineckia, Theropogon, Tupistra, Rohdea and Aspidistra, but now generally recognized as two tribes, Convallarieae (the former 4 genera) and Aspidistreae (the rest). Observed in this work were pollen morphology of 17 species and epidermal characters of leaves of 12 species. All the 7 genera are covered in observations. Pollen grains in Convallarieae (s. str.) are all monosulcate and boat-shaped (Plate 1: A-F). The exine is rather uniformly microperforate (Plate 1: A-F); only Theropogon is exceptional in this respect: it has rugulate exine (Plate 1: O, P). Tang and Zhang (1985) have pointed out the heterogeneity of Theropogon in this tribe. Pollen morphology in the tribe Aspidistreae is widely variable. The genera Tupistra and Rohdea were shown to have monosulcate and boat-shaped pollen grains. Their exine is perforate or reticulate (Plate 1: G-N). Pollen grains in the genus Aspidistra, however, are nonaperturate and spheroidal. The exine in the genus varies from crass-rugulate, variously gemmate to tuberculate-baculate (Plate 2; A-H). The pollen morphology of Aspidistra is therefore distinctly different from that of Tupistra and Rohdea, which supports the Nakai's (1936) establishment of the tribe Rohdeae for Tupistra and Rohdea. Therefore, Krause's Convallarieae is reasonably divided into at least three tribes, Convallarieae (Speirantha, Convallaria, Reineckia and Theropogon), Aspidistreae (Aspidistra) and Rohdeae (Rohdea and Tupistra). The pollen characters of all the 7 genera are shown in Table 1. The evolutionary trends of pollen morphology (aperture and exine) in the three tribes are discussed and our major view-points are shown in Fig. 1. Observations on epidermal characters of leaves show that in the Convallarieae (s. 1.) stomatal apparatuses are all anomocytic; cuticular layer on the upper epidermis is mainly striatethickened or rather uniformly thickened (Plate 2: J--P; Plate 3: A-C, F-N), whereas in the genus Convallaria the cuticular layer is squamosely thickened (Plate 2: I; Plate 3: D, E).The epidermal characters of leaves in the 7 genera are summarized in Table 2.  相似文献   

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