广西蕨类植物孢子形态的研究Ⅱ.铁角蕨属

利用光学显微镜和扫描电子显微镜对广西产9种铁角蕨属植物即拟狭翅铁角蕨、黑柄铁角蕨、剑叶铁角蕨、长生铁角蕨、岭南铁角蕨、石生铁角蕨、阴湿铁角蕨、半边铁角蕨和细裂铁角蕨植物的孢子形态进行了观察,对每个种的形态特征进行了详细描述,其中5种铁角蕨属植物孢子的表面纹饰为首次报道。结果如下:9种铁角蕨属植物孢子都为单裂缝,两侧对称,极面观为椭圆形或近圆形,赤道面观为肾形、椭圆形或近圆形。主要纹饰类型有翅脊状纹饰、翅状纹饰和脊状纹饰类型。讨论了各种间的差异。为铁角蕨属的分类和系统演化研究提供孢粉学的资料。     

华中铁角蕨孢子纹饰形成的超微结构观察

利用透射电子显微镜对铁角蕨科(Aspleniaceae)华中铁角蕨(Asplenium sarelii Hook.)孢子及其纹饰的形成过程进行观察。结果表明:①华中铁角蕨孢子囊发育为薄囊蕨型;②孢子外壁表面光滑,远极面的外壁厚约0.8~1.1μm,近极面的外壁厚约1.4~1.8μm;③孢子周壁厚度约4~5μm,染色较外壁深,分为内层和外层;内层紧帖外壁表面,其上具柱状、瘤状或疣状突起;外层向外隆起形成脊状纹饰的轮廓,脊的下方具空腔,脊的顶端具翅;④铁角蕨型与鳞毛蕨型孢子外壁和周壁纹饰的形成过程具有相似性;⑤孢子的成熟度对于孢子形态的研究是至关重要的,只有完全成熟的孢子的表面纹饰才是稳定的。     

中国蕨类植物孢子形态的研究IV. 金星蕨科2

利用扫描电镜对中国产金星蕨科Thelypteridaceae 14属50种植物孢子形态进行了研究。孢子单裂缝,两侧对称,极面观为椭圆形、阔椭圆形或近圆形,赤道面观为肾形或圆形。极轴长为16.8-40.5 um,赤道轴长为12.8-58 um。根据表面纹饰,孢子可分为7种类型。(1)平滑:周壁表面光滑,少纹饰,如延羽卵果蕨Phegopteris decursive-pinnata。(2)网状纹饰:周壁外层形成绳索状条纹交织成网,如紫柄蕨属Pseudophegopteris。(3)环状纹饰:周壁外层形成由绳索状丝构成的环,排列在周壁表面呈网状、不规则网状或分散的网状。如方秆蕨属Glaphyropteridopsis和针毛蕨属Macrothelypteris的针毛蕨M. oligophlebia。(4)具流苏的翅状纹饰:周壁向外形成薄片状翅,翅的边缘流苏状或具齿,片连接成网状或拟网状。如金星蕨属Parathelypteris的海南金星蕨P. subimmersa、光脚金星蕨P. japonica、钝角金星蕨P. angulariloba,钩毛蕨属Cyclogramma的耳羽钩毛蕨C. auriculata,针毛蕨属Macrothelypteris的大部分种类和毛蕨属Cyclosorus的部分种类。(5)具穿孔的脊状纹饰:周壁向外形成高或低、窄或宽的脊状纹饰连接成网状或拟网状,脊上具大小不一的穿孔。如金星蕨属、龙津蕨属Mesopteris、凸轴蕨属Metathelypteris和卵果蕨P. connectilis。(6)鸡冠状纹饰:周壁形成的短翅或短的片状脊,呈鸡冠状。如毛蕨属Cyclosorus的大部分种类。(7)刺状纹饰:周壁表面形成各种刺状纹饰,如茯蕨属Leptogramma、圣蕨属Dictyocline、沼泽蕨属Thelypteris、普通假毛蕨Pseudocyclosorus subochthodes、钩毛蕨属的大部分种类和毛蕨属Cyclosorus的部分种类。根据孢子形态特征,对本科的一些属的关系进行了探讨。     

中国蕨类植物孢子形态的研究Ⅷ.岩蕨科

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。     

中国蕨类植物孢子形态的研究Ⅲ.金星蕨科1.毛蕨属

利用扫描电镜对中国产毛蕨属51种植物孢子形态进行了研究。结果表明：该属孢子为单裂缝,两侧对称,极面观为椭圆形,赤道面观为肾形,由周壁形成表面纹饰。表面纹饰可分为3种类型：(1)周壁具流苏状的翅状纹饰,表面有突起或穿孔,有19种属于此类型;(2)鸡冠状纹饰,有11种属于此类型;(3)刺状纹饰,有10种属于此类型。另外有11种具有上述纹饰的混合纹饰,被认为是中间类型。孢子的形态特征可作为该属的分类学和孢粉学研究的资料。     

中国蕨类植物孢子形态的研究 Ⅱ. 中国蕨科

利用扫描电镜对国产中国蕨科Sinopteridaceae植物9属61种6变种的孢子进行了观察。结果表明,该科植物的孢子可分为3种类型：(1)孢子球形,三裂缝;周壁较厚,疏松地包在孢子之外;外壁光滑,表面纹饰由周壁形成,呈网状、嵴状、刺状或皱状。除金粉蕨属Onychium和珠蕨属Cryptogramma外,该科其他属的植物都具此类型孢子。(2)孢子钝三角形,三裂缝;周壁较薄,由周壁和外壁共同形成表面轮廓,表面具疣状或颗粒状纹饰。具此类型孢子的只有珠蕨属。(3)孢子钝三角形,三裂缝,沿裂缝两侧各有一脊状隆起或瘤状纹饰;周壁薄,由外壁形成表面纹饰的基本轮廓;具赤道环、近极脊和远极脊。具此类型孢子的只有金粉蕨属。另外,从孢粉学的角度对该科的分类和系统演化进行了探讨。     

中国介蕨属孢子形态的研究

采用光学显微镜和扫描电子显微镜对国产介蕨属Dryoathyrium 14种植物及宁陕蛾眉蕨Lunathyri- um ningshenense 的孢子形态进行了观察。介蕨属孢子单裂缝,两侧对称,极面观为椭圆形,赤道面观为半 圆形或肾形。根据其周壁褶皱隆起形成的表面纹饰,介蕨属孢子可分为3种类型：第一种类型的周壁 具有网状或拟网状脊状纹饰,具此类型的种有翅轴介蕨D．pterorachis,中华介蕨D．chinense,朝鲜介蕨 D．coreanum;第二种类型的周壁具有裂片状、弯裂片状或瘤状突起,具此类型的种有介蕨D．boryanum, 陕甘介蕨D．confusum,无齿介蕨D．edentulum,鄂西介蕨D.henryi,华中介蕨D．okuboanum,川东介 蕨D．stenopteron,刺毛介蕨D．setigerum,绿叶介蕨D．viridifrons;第三类型的周壁具有刺状、不规则 棒状或乳头状突起,具此类型的种有直立介蕨D．erectum,镰小羽介蕨D．falcatipinnulum,蛾眉介蕨D． unifurcatum。宁陕蛾眉蕨的孢子形态与朝鲜介蕨D．coreanum 十分相似,支持将前者作为后者的异名的分类处理。     

中国冷蕨属孢子形态研究

采用光学显微镜和扫描电子显微镜对中国产冷蕨属(Cystopteris Bernh.)8种植物的孢子进行详细的观察与比较。结果表明:(1)冷蕨属孢子均为单裂缝,两侧对称,极面观为椭圆形,赤道面观为肾形。但不同种孢子在大小和周壁纹饰等方面均有差异。(2)依据周壁表面纹饰将冷蕨属植物分为3种类型:第一种类型是刺状纹饰(或以刺状纹饰为主),主要有冷蕨(Cystopteris fragilis)、西宁冷蕨(C.kansuana)、膜叶冷蕨(C.pellucida)、藏冷蕨(C.tibetica)、欧洲冷蕨(C.sudetica)和宝兴冷蕨(C.moupinensis);第二种类型是瘤状纹饰,主要有高山冷蕨(C.montana);第三种类型是颗粒状纹饰,主要有皱孢冷蕨(C.dickieana)。依据孢子纹饰的类型支持高山冷蕨作为独立类群,同时发现颗粒状纹饰是皱孢冷蕨的明显特征。     

中国蹄盖蕨属植物孢子形态的研究

利用扫描电子显微镜对我国产蹄盖蕨属44种植物的孢子进行了观察。结果表明,该属孢子形态为单裂缝,两侧对称,极面观为椭圆形,赤道面观为豆形。外壁表面光滑,由周壁形成表面纹装饰。根据周壁的结构和表面纹饰,可分为两种类型;一是周壁外层发达,形成粗大的脊状纹饰,有11种属此类型;二是周壁外层很薄或不完全发育,由周壁内层或中层形成表面纹饰,有33种属此类型纹饰。本文还就本属的孢子形态特征以及与本属的属下分类关系、本属与邻近属的关系等进行了讨论。     

铁角蕨属4种植物配子体发育的比较研究

以腐叶土为基质培养铁角蕨(Asplenium trichomanes L.)、阿尔泰铁角蕨[A.altajense(Kom.)Grubov]、假大羽铁角蕨(A.pseudolaserpitii folium Ching)和细裂铁角蕨(A.tenui folium D.Don)的孢子,用光学显微镜观察并比较它们的配子体发育过程,以期为铁角蕨属的系统学研究提供基础资料.结果显示,4种铁角蕨属植物配子体均具有:孢子两面型、单裂缝、周壁具褶皱、书带蕨型萌发,成熟原叶体心形,原叶体具有毛状体等共同特征,表明铁角蕨属的演化处于较进化的系统位置,但它们的毛状体形态和细胞数目明显不同,可为属内分系提供依据.研究发现,4种铁角蕨属植物配子体的边缘细胞形状以及假根的形态和数量均有差异,其叶绿体能象单细胞一样进行无丝分裂,强光照射下叶绿体向相邻细胞的侧壁集中等现象.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.