十字花科四属植物叶片的表皮特征

对十字花科岩荠属、阴山荠属、泡果荠属、棒毛荠 属植物的叶表皮特征进行了扫描电镜观察,结果表明：表皮细胞多为不规则形,气孔主要分布于表皮,垂周壁上有明显的波状嵴或沟槽状下陷,平周壁上有各咱条纹状角质层纹饰。这些微形态特征在属间有明显的类群特异性,又有一定的过渡类型,为岩荠属及近缘属的合理划分提供一定的证据。     

阴山荠属,泡果荠属,棒毛荠属和岩荠属的扫描电镜观察

以阴山荠属、泡果荠属、棒毛荠属和岩荠属的18种植物取用实验材料,对果实外表皮、种子外种皮、毛和花粉粒等特征鉴别器官进行扫描电镜观察,提供36张照片资料,并以检索性状比较属间特征,证明该4属作为各自独立的属是恰当的。     

泡果荠属和阴山荠属（十字花科）的分属界限及两属的分类校订

泡果荠属Hilliella和阴山荠属Yinshania是十字花科中国特有的两小群植物,但是,它们的分属界定却一直颇有争议。本文结合前人的研究结果重新对这两群植物做了研究,从而进一步确认这两群植物应该界定为两个属,即泡果荠属和阴山荠属。文中比较了两属间重要的性状特征,并指出它们的主要区别在于:泡果荠属果实无假隔膜,种子较大,表面具小瘤状突起,染色体倍性为六倍体（2n=6x=42）;而阴山荠属果实有假隔膜,种子较小,表面具网纹,染色体倍性为二倍体（2n=2x=12）。两属其他方面如叶形态、叶表皮结构、被毛类型     

中国拳参属(蓼科)植物叶脉序式样的研究

用清净标本制作法对中国产拳参属（Bistorta）（蓼科）12种1变种植物的叶脉序式样在光镜下进行了比较研究。结果表明,叶脉序式样可分为3种类型：（1）环结曲行羽状脉,边缘末级脉不完全,加粗且外卷;（2）环结曲行荆状脉,二级脉与其余各级脉近等粗,边缘末级脉具边脉,不加粗;（3）直行羽状脉,盲脉无或偶有,边缘末级脉不完全,不加粗。依据叶脉序式样,结合其植物习性及外部形态特征,将拳参属植物划分为3个组：拳参组section Bistortu,乌饭树叶蓼组section Vacciniifolia F．Z．Li,L．X．Liu ＆ Y．T．Hou,sect．nov．和匍枝蓼组section Bambuphyllum F．Z．Li,L．X．Liu ＆ Y．T．Hou,sect．nov．。     

中国木犀属植物叶脉形态及其分类学意义

观察了中国木犀属植物4组19种叶脉形态。主要分析木犀属植物叶片脉序走向,脉序为环结曲行或半直行羽状脉。二级脉急转曲行或半直行,叶脉分支一般为4级,少数5级。盲脉1～2次分支,少数3次或不分支。仅柊树叶缘末级脉汇合成边脉.部分叶缘具齿,叶缘齿性状不稳定,因其内主脉不同而在本属种间表现出一个连续的变异过程。圆锥花序组与李榄属和木犀榄属从叶片脉序特征方面表现出较近的亲缘关系。四个组的叶脉形态在演化上关系上与花粉形态表现相一致。编写了叶片脉序特征分种检索表。     

阴山荠属和泡果荠属植物染色体数目及过氧化物酶同工酶的比较

阴山荠属和泡果荠属受试种类的染色体数目是：柔毛阴山荠（Ｙ．ｈｅｎｒｙｉ（Ｏｌｉｖ．）Ｙ．Ｈ．Ｚｈａｎｇ）２ｎ＝１２,叉毛阴山荠（Ｙ．ｆｕｒｃａｔｏｐｉｌｏｓａ（Ｋｕａｎ）Ｙ．Ｈ．Ｚｈａｎｇ）２ｎ＝１２,双牌泡果荠（Ｈ．ｓｈｕａｎｇｐａｉｅｎｓｉｓＺ．Ｙ．Ｌｉ）２ｎ＝４４,黟县泡果齐（Ｈ．ｙｉｃｉａｎｅｎｓｉｓＹ．Ｈ．Ｚｈａｎｇ）２ｎ＝４２,双牌泡果（Ｈ．ｐａｒｄｏｘａ（Ｈａｎｃｅ）Ｙ．Ｈ．Ｚｈａｎ     

十字花科2个种的染色体数目

棒毛荠 Cochleariella zhejiangensis (Y. H. Zhang) Y. H. Zhang et R. Vogt与浙江泡果荠 H illiella warburgii (O. E. Schulz) Y. H. Zhang et H. W. Li同属十字花科 ,亲缘相近。前者因果瓣具十分独特的棒状毛和其它一些特征而独立成属 [1 ,2 ] 。后者原在广义岩荠属 Cochlearia L.中东亚分布的一个组中 ,该组后经整理扩大提升成泡果荠属 [3]。对于该 2种的分类归属 ,争议颇多。赵一之 [4]认为两者差别不大 ,将前者作为后者的变种更为恰当 ,并将棒毛荠属、泡果荠属与阴山荠属合并。陆莲立 [5]认为两者果瓣上的差别是同一植物种…     

阴山荠属的研究

本文为阴山荠属和泡果荠属的分类研究提供了染色体数目试验结果。受试种类按染色体数目的分异形成两大类群,与按形态地理分类法得出的结果一致。阴山荠属(Yinshania):柔毛阴山荠Y.henryi,2n=12;叉毛阴山荠Y.fur-catopilosa,2n=12;乾宁阴山荠Y.qianningensis,2n=12;泡果荠属(Hiliela):昌化泡果荠H.changhuaensis.2n=42,奇异泡果荠H.paradoxa,2n=42;双牌泡果荠H.shuangpaiensis,2n=44;弯缺泡果荠H.sinuata,2n=44;黟县泡果荠H.yixianensis,2n=42。染色体数目结合形态学和地理分布研究,支持两属作为各自独立的属存在。本属是中国特有分布属,形态演化研究表明,本属阴山荠组是较原始的类群,小果组是较进化的类群。文中讨论了属中各种的分布规律和全属的分布特点,认为川西及其邻近地区是本属多样化中心和近代分布区中心,本属可能是从该地区,并随着新生代第三纪喜马拉雅造山运动和青藏高原的崛起,以及第四纪冰期、间冰期的迭次变化产生的全球性气候波动而分化迁移。本属基本上属亚热带、暖温带的半湿润半干旱生态类型。根据本属重要器官较稳定的特点,以及地区性特有成分较高的特点,认为本属是较古老的中国特有成分     

绣球亚科的脉序研究

本文对绣球亚科全部９个属中选取４５个种或变种作了叶脉序的研究。绣球亚科除黄山梅属外,大体呈曲行羽状脉。叉叶蓝属,蛛网萼属和草绣球属同具真曲行羽状脉和相似的高级脉序;赤壁草属和冠盖藤属表现出明显的环结曲行羽状脉式样;钻地风属多呈现分支曲行羽状脉式样;常山属和绣球属包含多种过渡类型,与其它属密切相连。黄山梅属脉序为独特的羽状达缘型式样,明显表现出向掌状脉的过渡,与其它属不同。脉序研究支持Ｔａｋｈｔａｊａｎ系统把黄山梅属提升为亚科的处理,同时又表明从脉序性状来看,绣球亚科各属之间性状彼此重叠,没有十分明确的界限。     

关于浙江泡果荠和棒毛荠的分类问题

再次对浙江泡果荠Hilliella warburgii和棒毛荠Cochleariella zhejiangensis作比较研究后,本文认为：两者差别明显,尤其是后者子房和果实表面密被发达的膜质棒状毛,又有各自不同的地理分布区,显然是不同属植物。棒毛荠属(单型属)的属名模式是Cochleariella zhejiangensis Y．H．Zhang et R．Vogt。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

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     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

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