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1.
青藏高原东缘风毛菊亚属16种植物果皮微形态研究   总被引:1,自引:0,他引:1  
采用扫描电子显微镜对青藏高原东缘风毛菊亚属中的16种植物果实表皮微形态特征进行观察,结果表明:(1)果皮纹饰类型为:条纹型,有隔条纹型和网纹型。(2)根据种内个体间、组内种间以及组间的比较, 认为在风毛菊亚属中, 果实表皮显微特征在种内个体间比较稳定, 变异很小; 同组内种间表现出较大的相似性而不同组间存在着一定差异。说明在组和组下等级的分类学处理以及在系统位置和亲缘关系的探讨上, 果实显微特征具有重要的分类学价值。  相似文献   

2.
苔草属果实表皮的超微结构及其在分类学上的意义   总被引:8,自引:0,他引:8  
报道了国产苔草属,两亚属,7组中的16种植物在电子显微镜下果实表皮的特征和研究结果。根据种内个体间、组内种间以及亚属间的比较,作者认为在苔草属中,果实表皮显微特征在种内个体间比较稳定,变异很上;同组内种间表现出的较大相似性和不同组间存在的一定差异性。说明在组和组下等级的分类学处理以及在系统位置和亲缘关系的探讨上,果实显微特征具有重要的分类学价值。同时由于是微特征在各间甚至属间相互交叉和渗透,在划分  相似文献   

3.
中国柴胡属植物叶表皮特征及系统学意义   总被引:4,自引:0,他引:4  
利用光学显微镜和扫描电镜对我国柴胡属(Bupleurum L.)13种(含1变种)植物的叶表皮进行了观察,首次报道了它们的微形态特征。结果表明:除了大叶柴胡(B.longiradiatum Turczaninow)气孔器仅存在于下表皮,其余12种柴胡的上、下表皮都存在气孔器,气孔器类型包括不规则型和不等型两种。叶表皮细胞形状为多边形或不规则型,垂周壁式样可区分为平直一弓形、浅波状。保卫细胞壁加厚明显,极端联合形成极层结构。在扫描电镜下,气孔器内陷于表皮细胞间。角质膜条纹状,有的条纹隆起,有的条纹上附有蜡质胶状分泌物和鳞片。光镜和电镜下叶表皮柴胡属微形态表现出相当高的多态性;而在特定的分类群中,又表现为高度的一致性,为种间分类提供了新的证据。  相似文献   

4.
利用光学显微镜和扫描电镜对21种珍珠菜属植物叶表皮纹饰特征进行了研究。根据叶表皮外壁纹饰特征,可以明显的划分为两种类型,即黑腺珍珠菜型和细梗香草型。这两种类型与以雄蕊群的构造为主要依据的属下分类系统的对应关系不密切,表明叶表皮纹饰特征在亚属级水平上分类学意义不大。但该属植物叶腺体的有无,颜色和分布以及叶表皮纹饰特征在种内相当稳定,种间差异较大,在种级水平上具有重要的分类学意义。  相似文献   

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用光学显微镜和扫描电镜,较全面地观察了铁线莲属(Clematis)植物和邻近类群和叶表皮特征,并对其系统学意义进行了讨论。在光学显微镜下,观察了铁线莲属12组63种5变种及其同族邻近类群3属9种;在扫描电镜下,观察了铁线莲属7组27种2变种及其邻近类群2属6种植物的成熟叶表皮细胞及气孔器的特征,在光学显微镜下可见:叶表皮细胞形状(表面观)为多边形、不规则形,垂周壁式样为较平直,浅波状和波状,气孔器普遍存在于下表皮,少数种的上表皮也有分布,其类型均为无规则型,在扫描电镜下可见:叶片通常具有条纹或有颗粒状或鳞片状附属物,气孔器外拱盖内缘通常为浅波状或近平滑。在黄花铁线莲组(sect.Meclatis(Spach)Tamura)和灌木铁线莲组(sect.Fruticella Tamura)中,叶表皮具有双面气孔器的特征对于组下亚组的划分有一定意义。并且叶表皮特征对于一些种的分类学处理也有一定的价值,同时也为属下组间的系统进化关系提供了一些线索。  相似文献   

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利用扫描电镜和解剖镜对西藏色季拉山区分布的龙胆科6属20种植物种子微形态进行观察研究。结果显示:这20种植物的种子颜色有黑色、黄色、黑褐色、黄褐色、灰褐色和红棕色6种;种子形状分为长卵球形、卵球形、椭圆球形、矩圆形和近球形;表皮纹饰可分为4种类型,即网纹型、条纹型、疣状型和嚼烂型,其中网纹型又细分为6个亚型。根据种子微形态特征,笔者对龙胆科相关属的进化趋势、分类学意义和分类鉴定等进行了讨论,认为獐牙菜属(Swertia L.)和龙胆属(Gentiana(Tourn.)L.)进化程度较高;从种子微形态特征上看肋柱花属(Lomatogonium A.Br.)、花锚属(Halenia Borkh.)和假龙胆属(Gentianella Moench.)间有较近的亲缘关系;龙胆科各属种子表皮纹饰特征与分类系统基本吻合。本研究表明种子微形态在植物分类研究中具有十分重要的意义,可作为植物系统划分、鉴定和进化研究的参考性状。  相似文献   

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在光学显微镜和扫描电镜下,对栒子属(Cotoneaster Medikus)2组15种植物的叶表皮特征进行了观察,发现疏花组(Sect. Cotoneaster)植物叶表皮细胞多为多边形,垂周壁一般为平直—弓形,气孔均为无规则型;单花组(Sect. Uniflos)植物叶表皮细胞常不规则型,垂周壁多浅波状,气孔除无规则型(anomocytic)外还兼有十字型(staurocytic)、四分体型(tetracytic)和等三体型(isotricytic)。依据气孔周围角质膜特征等叶表皮性状,把15种植物分为W型、S型和I型,其中W型是S型的特化类型,疏花组的种类为W型或S型,单花组的种类为I型。叶表皮微形态特征可以为栒子属植物组及种的分类学处理提供解剖学资料。  相似文献   

8.
堇菜属(Viola)植物种类多、分布广、形态变异大,物种鉴定和分类系统争议较大。因此,为解决该属物种的分类学问题,以中国云南产的8种堇菜属植物为研究对象,利用显微镜和石蜡切片技术观察叶形态解剖特征,结果如下(:1)叶型可分为4种:肾形、戟形、卵形和三深裂(;2)叶片边缘和叶脉处稀疏分布着单细胞单列毛状体,可分为3类:短柱状、中柱状和长柱状(;3)叶表皮细胞垂周壁式样有平直-弓形、浅波状和深波状,气孔器类型有平列型、横列型和无规则型;气孔多为椭圆形,少数为近圆形;(4)叶中脉处上下表皮突起有均等型和不等型(;5)叶柄横切面轮廓和主维管束形态相关,前者为椭圆形、半圆形和近圆形,后者为浅U型、深U型和圆形。分析结果表明,堇菜属的叶型、表皮毛被、叶表皮细胞形态、气孔类型、叶中脉处的上下表皮形态、叶柄横切面及主维管束轮廓等,在种间差异明显,可以用作属内物种划分和近似种间的区别,支持长萼堇菜(V. inconspicua)、早开堇菜(V. prionantha)和紫花地丁(V. philippica)是一组有近缘关系的独立种。  相似文献   

9.
应用光学显微镜和扫描电子显微镜对29种野豌豆属植物叶表皮微形态特征进行了观察。结果显示:叶表皮细胞形状有无规则形和多边形2种,垂周壁式样有深波状、浅波状和平直-弓形;表皮角质层纹饰微形态多样,大多数植物叶片表面不具有腺毛或仅中脉有,少数植物叶片表面具腺毛;部分叶表皮上有柔毛,少数植物无毛。气孔器存在于上表皮、下表皮、或上下表皮均有,形状为椭圆形、卵圆形,均为无规则型。野豌豆属植物叶表皮的这些微形态特征,在属内组间没有明确的规律性,但可为探讨本属种间的分类学及亲缘关系提供依据。  相似文献   

10.
国产润楠属植物的叶表皮特征及其系统学意义   总被引:3,自引:0,他引:3  
对45种国产润楠属(Machilus Nees)植物的叶表皮进行光学显微镜和扫描电镜观察,其中31种为首次报道.结果表明:润楠属植物叶表皮细胞形状为多边形或不规则形,气孔复合体均为平列型且仅分布在下表皮;上下表皮细胞的垂周壁式样有5种类型:平直、圆滑、浅波、波状、平直-弓形;下表皮毛被有(稀疏、密集或非常密集)或无;上表皮平周壁纹饰类型有:点状、平滑、条纹(或波浪条纹);下表皮内面平周壁纹饰类型有:不规则、平滑、粗糙网状、微毛状、颗粒状、鳞片状.这些特征在本属种间存在较显著的差异,可作为区分种类的辅助特征和种间亲缘关系,因而对润楠属植物的分类学研究和亲缘关系的确定有较大意义.  相似文献   

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K. Hausmann 《Protoplasma》1979,100(2):199-213
Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.  相似文献   

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Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices  相似文献   

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This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.  相似文献   

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Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418  相似文献   

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