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1.
Use of hexamethyldisilazane (HMDS) as a final dehydrating solution provides robust, undistorted secondary electron images of a variety of angiosperm and gymnosperm pollen grains, including those considered to be susceptible to collapse in the scanning electron microscope. Ease of handling, low cost, lack of specialized equipment, minimal expenditure of time, and high rate of success are factors that favor HMDS over other drying agents for preparing pollen grains for scanning' electron microscopy.  相似文献   

2.
借助光学显微镜、扫描电镜和透射电镜对五列木科Pentaphylacaceae和肋果茶科Sladeniaceae花粉进行了观察,并与山茶科Theaceae若干属的花粉进行了详细的比较,同时参考了猕猴桃科Actinidiaceae的花粉特征。研究表明,肋果茶科的花粉与山茶科的花粉具有较多的相似性,如其形状和大小与山茶科中厚皮香亚科的几乎一致;而花粉的表面纹饰(粗糙至模糊的皱波状纹饰)则与山茶属,Freziera属和厚皮香亚科部分属的花粉纹饰相类似。从花粉外壁的结构看,肋果茶的花粉与石笔木属和山茶属的更接近,表现为:花粉外壁层次分化明显,复盖层和柱状层均较厚,外壁内层薄。而五列木科花粉除了形状和萌发孔类型与山茶科的相似外,其纹饰特征和外壁结构均与山茶科的差异较大,如五列木科花粉表面近光滑,外壁覆盖层较簿,柱状层很不发达,外壁内层相对较厚等。孢粉学上认为,肋果茶科与山茶科具有更为密切的关系,五列木科则与山茶科较疏远。支持把肋果茶科作为一个属置于山茶科内或作为山茶科的一个亚科  相似文献   

3.
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   

4.
云南松花粉形态研究   总被引:3,自引:0,他引:3  
在云南松(Pinus yunnanensis Fr.)小孢子发生发育过程中,花粉母细胞、四分孢子及花粉粒均见有粘连现象。花粉气囊的形态、大小变化复杂多样。除一般具两个正常气囊的花粉粒外,还观察到气囊不发育、具一个气囊、二个异形气囊、三个气囊和四个气囊的花粉粒。成熟花粉壁从外至内可分为外壁外层、外壁内层、内壁外层和内壁内层,它们的构成成分及形态均有明显差别。贮存后花粉的内壁结构发生了明显变化。  相似文献   

5.
葫芦科8属11种植物花粉形态的扫描电镜观察   总被引:2,自引:1,他引:1  
利用扫描电子显微镜,对葫芦科8属10种1变种植物的花粉形态进行观察研究。结果显示:冬瓜属、葫芦属和栝楼属的花粉粒为近球形,具3孔沟;苦瓜属、西瓜属和丝瓜属的花粉粒为长球形,具3沟;黄瓜属的花粉粒为近球形,具3孔;南瓜属的花粉粒为球形,具散孔。花粉粒大小、形状和外壁雕纹属、种间差异显著。  相似文献   

6.
Pollen morphology of 62 species in Aconitum L. was investigated with light and scanning electron microscopies. The pollen grains in this genus are 3-colpate and exhibit spinulate surface pattern in all the species. According to the shape of pollen grains in equatorial view Aconiturn L. may be divided into three types. Type Ⅰ pollen grains are wide elliptic; Type Ⅱ are narrow-elliptic and type Ⅲ are rectangular or close to square in shape. The pollen characteristics among species are very similar. The morphological information of the pollen grains shows that species of Aconiturn L. are a natural taxon.  相似文献   

7.
The methods using plants for biomonitoring of air and soil quality are simple, cheap, and fast and can supplement the classical physicochemical methods. In this study, biological pollen characterization of some collected legume species from an aluminum smelter area in Iran (IRALCO) was carried out to determine the actual value of pollen as a bioindicator of the effects of soil and atmospheric pollution. Young buds and flowers of six legumes (Cercis siliquastrum L., Medicago sativa L., Robinia pseudoacacia L., Melilotus officinalis (L.) lam, Trifolium repens L., and Sophora alopecuroides L.) in polluted and control plants were removed and compared. Studies of light and electron microscopic preparation showed some abnormalities during pollen development in affect of fluoride pollution. The viability of pollen grains estimated by staining with acetocarmine shows sharp differences in smearing advanced pollen grains from abnormal ones. Except M. officinalis, the pollen grains of C. siliquastrum, M. sativa, R. pseudoacacia, T. repens, and S. alopecuroides in polluted areas showed light, partial, or no staining with acetocarmine, whereas almost all of the control ones clearly stained. Observation of the pollen grains by light microscopy and scanning electron microscopy showed the significant effect of fluoride on shapes and sizes of pollen grains. The stimulation and inhibition of these pollen characteristics depend on the pollen species as well as on the pollutant and its concentration. Therefore, pollen grains provide essential information on biological impact of pollutants and they are good candidates for biomonitoring the atmospheric and edaphic pollutions.  相似文献   

8.
Xyridaceae are a predominantly tropical family of five genera that exhibit two pollen morphologies often considered to be of taxonomic importance. Xyris comprises about 95% of the species and is characterized by medium to large, elliptic, sulcate pollen grains. The other pollen class is spheroidal grains without an evident aperture. Many of the species with spheroidal grains have remarkably large and ornamented pollen found to be species specific in earlier research. A scanning electron microscopy investigation of 23 taxa representing all genera with spheroidal pollen revealed new data to further distinguish the genera based on pollen characters. Reliable specific pollen characters need to be evaluated in a statistical study.  相似文献   

9.
广西野生毛葡萄雌雄株花粉形态学研究   总被引:1,自引:0,他引:1  
通过电镜扫描,对原产于广西石山地区的野生毛葡萄雌、雄株花粉形态进行比较研究。结果表明,野生毛葡萄花粉粒为小型花粉粒,雌、雄株花粉粒形状及纹饰、萌发孔特征均有较大差异:雄株花粉粒萌发孔为三孔沟类型,长球形,花粉粒P/E=1.20(P极轴值,E赤道轴值);雌株花粉粒无萌发孔,近球形,花粉粒P/E=1.12。  相似文献   

10.
Using an X-ray microanalysis system fitted with variable-pressure scanning electron microscopy, we noted that many calcium crystals accumulated under the stomium in the anther of Petunia. When the anther was dehisced and pollen grains were released from the stomata, the calcium crystals adhered to pollen grains and moved to the stigma together with pollen grains. In contrast, an X-ray microanalysis of the stigma surface before pollination detected no calcium emission on the stigma surface. Furthermore, pollen germination and pollen tube growth in medium without Ca occurred as in complete medium. However, after the pollen grains had been washed with abundant germination medium without calcium, pollen germination in the medium without Ca was inhibited. These results show that the calcium crystals dissolved in the aqueous drop under the exudate on the stigma and supplied calcium ions for pollen germination. In addition, calcium crystals were produced not only in the anther of Petunia but also in Nicotiana, suggesting that calcium crystals supply pollen grains with the calcium ions required for pollen germination and serve to improve reproduction efficiency in Solanaceae.  相似文献   

11.
This paper describes dispersed angiospermous pollen grains from the Maastrichtian of Sakhalin, Russia, with scanning electron microscopy. These pollen grains includeClavatipollenites, Tricolpites, andBetulaepollenites. Exine sculpture of the pollen grains are shown in detail. The palynomorphs imply a wide range of angiosperm diversity during Maastrichtian time at the mid- or high-latitudes in the eastern Eurasia.  相似文献   

12.
This paper presents a pollen-morphological study of Alangium, a genus mainly restricted to the tropics of the Old World, of which 18 of the 19 known species were studied. The pollen grains, studied with the use of a light microscope, a transmission electron microscope and a scanning electron microscope, were classified into 15 pollen types, to which a key is given. Comparison of fossil and recent grains produced some information about both the evolutionary trends in the characters of the pollen grains and the phytogeography of Alangium.  相似文献   

13.
须芒草族植物花粉形态的观察   总被引:2,自引:1,他引:1  
在光学显微镜下和扫描电镜下对禾本科须芒草族(Andropogoneae)中分隶于8个亚族34个属的36种植物的花粉进行形态面容和比较研究。结果显示,本族植物花粉形态较为一致,花粉近形或扁球形,单萌发孔,孔,周围加厚,具盖,外壁表面散布有颗粒。这表明其是一个自然类群。总体来讲,芬烨大的演化分异,只是表面纹饰的和芬烨大小有一;定的差异。纹饰可分为三种类型粗糙型,不明显疠状突起才明显疠状突起型。花粉开矿  相似文献   

14.
In electron micrographs it could be shown that hazelnut (Corylus avellana) pollen grains are covered on their surface by a diffusible 10 nm thick lamellar layer. On pollen surface as well as in pollen extract this layer could be precipitated and stained by the polycationic dye Cuprolinic blue. By subsequent application of both immunogold labeling with serum from a hay-fever patient allergic to tree pollen grains and histochemical detection with Cuprolinic blue this pollen surface layer proved to be an effective antigen.  相似文献   

15.
Summary In electron micrographs it could be shown that hazelnut (Corylus avellana) pollen grains are covered on their surface by a diffusible 10 nm thick lamellar layer. On pollen surface as well as in pollen extract this layer could be precipitated and stained by the polycationic dye Cuprolinic blue. By subsequent application of both immunogold labeling with serum from a hay-fever patient allergic to tree pollen grains and histochemical detection with Cuprolinic blue this pollen surface layer proved to be an effective antigen.  相似文献   

16.
The Aurantioideae is one of seven subfamilies of the Rutaceae consisting of two tribes, the Clauseneae, containing five genera, and the Citreae, with 28 genera. Each tribe contains three subtribes. The pollen morphology of the subfamily Aurantioideae is described and illustrated for the first time based on light and scanning electron microscopy. Five pollen types have been recognised in the subfamily, based mainly on aperture number and exine ornamentation. The pollen grains show a high degree of intergeneric variation. Pollen grains of Clauseneae are 3-colporate, microstriate or microstriato-reticulate, whereas pollen grains of Citreae are almost always 4/5 colporate with exines varying from microperforate to coarsely reticulate. Congruence between pollen types and the currently accepted classification is discussed, as well as the systematic implications of pollen morphology for the subfamily.  相似文献   

17.
以白莲花粉为实验材料,介绍了进行花粉形态计算机量化分析的步骤。花粉经醋酸法处理后,用电子显微镜对花粉进行观察照相,尔后用计算机技术对花粉电镜照片进行处理,最后用C语言编制了计算花粉形态面积的计算机程序。结果表明:花粉计算机量化分析有助于快速定量测定有关花粉形态指标,是花粉数量分类的一种有效方法。  相似文献   

18.
以白莲花粉为实验材料 ,介绍了进行花粉形态计算机量化分析的步骤。花粉经醋酸法处理后 ,用电子显微镜对花粉进行观察照相 ,尔后用计算机技术对花粉电镜照片进行处理 ,最后用C语言编制了计算花粉形态面积的计算机程序。结果表明 :花粉计算机量化分析有助于快速定量测定有关花粉形态指标 ,是花粉数量分类的一种有效方法。  相似文献   

19.
Summary. Rapid diffusion of allergenic proteins in isotonic media has been demonstrated for different pollen grains. Upon contact with stigmatic secretion or with the mucosa of sensitive individuals, pollen grains absorb water and release soluble low-molecular-weight proteins, these proteins enter in the secretory pathway in order to arrive at the cell surface. In this study we located allergenic proteins in mature and hydrated-activated pollen grains of Parietaria judaica L. (Urticaceae) and studied the diffusion of these proteins during the first 20 min of the hydration and activation processes. A combination of transmission electron microscopy and immunocytochemical methods was used to locate these proteins in mature pollen and in pollen grains after different periods of hydration and activation processes. Activated proteins reacting with antibodies in human serum from allergic patients were found in the cytoplasm, wall, and exudates from the pollen grains. The allergenic component of these pollen grains changes according to the pollen state; the presence of these proteins in the exine, the cytoplasm, and especially in the intine and in the material exuded from the pollen grains, is significant in the hydrated-activated studied times, whereas this presence is not significant in mature pollen grains. The rapid activation and release of allergenic proteins of P. judaica pollen appears to be the main cause of the allergenic activity of these pollen grains. Correspondence and reprints: Department of Plant Biology, Faculty of Biology, University of León, Campus de Vegazana, 24071 León, Spain.  相似文献   

20.
12种十字花科植物花粉形态研究   总被引:1,自引:0,他引:1  
采用扫描电子显微镜对十字花科8属12种植物的花粉形态特征进行了观察分析.其中8种为首次报道.观察结果表明:4族8属12种十字花科植物花粉形态的一般特征为:花粉粒长球形至超长球形;极面观三裂圆形,少数四裂圆形;外壁纹饰为网状或细网状纹饰;三沟,偶四沟.12种植物的花粉可划分为5种类型:(1)花粉粒长球形,网状纹饰,三沟;(2)花粉粒超长球形,网状纹饰,三沟;(3)花粉粒长球形,细网状纹饰,三沟;(4)花粉粒超长球形,细网状纹饰,三沟;(5)花粉粒长球形,三或四沟,网状纹饰.十字花科花粉形态特征在不同族间、不同属间以及同属不同种间均没有明显规律,在十字花科分类过程中,不宜单独以花粉形态特征作为依据.  相似文献   

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