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1.
利用扫描电镜对国产凤尾蕨科( Pteridaceae ) 2 属30 种4 变种植物孢子进行了观察。其中凤尾蕨属( Pteris) 29 种4 变种, 孢子三裂缝, 辐射对称; 极面观为钝三角形, 赤道面观为半圆形或超半圆形; 孢子极轴长26~54μm, 赤道轴长34~97μm; 外壁厚, 形成孢子表面纹饰的轮廓; 周壁薄, 紧贴于外壁上; 多数种类孢子外壁具沿赤道加厚的赤道环, 孢子表面呈瘤块状、疣块状, 或隆起的脊连成网状或拟网状等纹饰, 有的种类具近极脊和远极脊。凤尾蕨属植物孢子的形态稳定, 种间差异明显, 但孢子形态特征与孢子体的形态特征是不相关的。栗蕨属( Histiopteris) 植物孢子为单裂缝, 两侧对称, 极面观椭圆形, 赤道面观豆形; 孢子极轴长22~23μm, 赤道轴长29~36μm; 周壁很薄, 由外壁形成孢子纹饰的轮廓; 表面呈粗的块状纹饰。从孢子形态上看, 栗蕨属与凤尾蕨属有很大差异, 将其放在一个科中不合适。  相似文献   

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戴锡玲  王全喜 《西北植物学报》2007,27(11):2210-2216
利用扫描电镜对中国产岩蕨科(Woodsiaceae)3属18种植物孢子进行了观察。结果表明,孢子单裂缝,两侧对称,极面观为椭圆形或宽椭圆形,赤道面观为半圆形或超半圆形;极轴长32~50μm,赤道轴长43~61μm;外壁表面光滑,由周壁形成孢子表面纹饰的轮廓,根据表面纹饰,孢子可分为5种类型:(1)片状纹饰:周壁表面形成疏密不一的片状褶皱,并连成网状;(2)脊状纹饰:周壁表面形成脊状褶皱,并连成网状;(3)翅脊状纹饰:周壁表面具脊状褶皱,并连成网状,脊的顶端具流苏状不明显的低翅;(4)翅状纹饰:周壁外层形成翅状纹饰,翅的边缘较薄;(5)丝毛状纹饰:周壁结构疏松,由细丝交织成立体网状。上述孢粉学特征表明,岩蕨科是一个自然的类群,其3属的亲缘关系较近,都是岩蕨科的合理成员。  相似文献   

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利用扫描电镜对国产阴地蕨科(Botrychiaceae)3属12种植物孢子进行了观察.结果表明: 孢子具三裂缝;极面观为钝三角形或近圆形;赤道面观为半圆形或超半圆形.极轴长20~34 μm,赤道轴长31~40 μm.由外壁形成孢子表面纹饰的轮廓;周壁薄,疏松地覆盖在外壁表面.孢子表面纹饰可分为以下3种类型:①疣块状纹饰(verrucate-rugulate):孢子远极面形成顶端扁平而大的疣块状纹饰,再由疣块连接成短的条状或拟网状;②疣状纹饰(verrucate):孢子表面具大小不等的疣状纹饰,相邻的疣愈合成短条状或不愈合;③脊状纹饰(lophate):孢子表面具脊状褶皱,并连接成网状.从孢子形态、纹饰类型和孢壁结构看3属属内差异明显,属间差异不明显,研究结果支持阴地蕨科具1属--阴地蕨属,其下可分3个组.  相似文献   

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中国金粉蕨属孢子形态的研究   总被引:2,自引:1,他引:1  
于晶  王全喜  包文美 《植物研究》2001,21(2):227-230,T001,T002,T003
利用扫描电子显微镜对我国产金粉蕨属8种2变种蕨类植物的孢子进行了观察。结果表明,该属孢子形态较为一致。三裂缝,辐射对称,极面观为钝三角形或三角圆形,赤道面观为椭圆形,超半圆形成或扇形,周壁较薄,外壁突起形成表面纹饰的基本轮廓,具赤道环,近极脊和远极脊等结构,种间差异主要表现在远极面的纹饰形态上,从孢子形态上看,金粉蕨属与中国蕨科其它属差异较大,而与凤尾蕨属相似,建议将本属放在凤尾蕨科。  相似文献   

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利用扫描电镜对中国产卷柏科25种植物孢子形态进行了观察。结果显示:(1)卷柏科植物大孢子为球状四面体,辐射对称;具三裂缝,裂缝为孢子半径的1/2~3/4;极面观一般为三角圆形或近圆形,赤道面观为近圆形、近扇形或近椭圆形;极轴长为158~548μm,赤道轴长为196~675μm。(2)小孢子为球状四面体,辐射对称;具三裂缝,裂缝为孢子半径的1/2~3/4或几达赤道线;极面观一般为近圆形或三角圆形,赤道面观为近圆形或近扇形;极轴长为10~40μm,赤道轴长为17~63μm。(3)孢子表面具颗粒状、瘤状、疣状、刺状、棒状、网状、片状、疣块状和脑状纹饰。研究认为,孢子形态特征可以作为该科亚属及种的分类学依据。  相似文献   

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利用光镜、扫描电镜和透射电镜对凤尾蕨科(Pteridaceae)蜈蚣草(Pteris vittata L.)孢壁的形成和发育进行研究。结果表明:蜈蚣草孢子四面体型,极面观钝三角圆形,赤道面观半圆形或超半圆形,近极面具瘤状纹饰和近极脊,远极面具脊并连成网状,具赤道环;孢子具乌毛蕨型外壁,由外壁外层构成纹饰的轮廓;实心型周壁由2层构成,且内层薄、外层具小球体。结合孢子外壁和周壁的发育特征,认为凤尾蕨科与裸子蕨科和水蕨科的亲缘关系较近,支持将裸子蕨科和水蕨科置于凤尾蕨科。  相似文献   

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利用扫描电镜对中国产石松科6属9种1变型植物孢子形态进行了观察.结果表明:石松科植物孢子为四面体形,辐射对称;具三裂缝,裂缝为孢子半径的1/2~3/4或几达赤道线,有些种裂缝具唇状边缘;极面观一般为圆角三角形或近圆形,赤道面观为扇形或近椭圆形;极轴长为23~50 μm,赤道轴长为24~54 μm;由外壁形成孢子表面网状、棒状、脊状、拟网状、瘤状和颗粒状纹饰的轮廓;周壁薄,通常只有1层.从孢粉学特征看,石松属和扁枝石松属孢子形态有交叉,属间特征不明显;而小石松属、卡罗利拟小石松属、垂穗石松属和藤石松属的属间孢子形态特征明显.  相似文献   

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利用扫描电镜对中国产叉蕨科7属34种植物孢子的形态进行了观察。叉蕨科植物孢子为左右对称,极面观为椭圆形,赤道面观为半圆形、超半圆形或豆形;极轴长为18~38μm,赤道轴长为23~57μm;单裂缝,裂缝长度为孢子全长的1/2~2/3;孢子具脊状、翅状、刺状和耳状4种纹饰,孢子表面有时具细刺、颗粒或孔。通过孢粉学分析,叉蕨科依据孢子形态特征和依据孢子体形态特征的分类结果并不一致,孢粉纹饰类型呈现一定程度的属间交叉;支持将叉蕨科和鳞毛蕨科进行重新划分的MAARTEN J.M的新分类系统。  相似文献   

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中国蕨类植物孢子的形态Ⅶ.桫椤科   总被引:1,自引:0,他引:1  
对中国桫椤科(Cyatheaceae)11种植物的孢子形态进行了扫描电镜的研究。桫椤科孢子辐射对称,三裂缝,裂缝长度达孢子半径的3/4左右,极面观三角形,赤道面观为半圆形或扇形,孢子极轴长为27~42μm,赤道轴长为32~52μm。孢子表面纹饰是由周壁形成的,可分为4种类型,即条纹状、疣状、刺条状、短刺状。根据孢子的形态特征,对中国桫椤科孢子类型进行了划分,对属的划分问题进行了探讨。  相似文献   

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利用光学显微镜和扫描电子显微镜对广西产凤尾蕨科及其近缘科蕨科、姬蕨科和碗蕨科5属9种植物的孢子形态进行了观察研究,详细描述了9种植物孢子的形态及表面纹饰特征.井栏边草、刺齿凤尾蕨、隆林凤尾蕨、剑叶凤尾蕨、林下凤尾蕨、蕨和碗蕨植物的孢子为三裂缝,辐射对称;极面观为钝三角形,赤道面观为半圆形或超半圆形;栗蕨和姬蕨植物孢子为...  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

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Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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