大麦与纤毛鹅观草属间杂种F5和BC1F4的同工酶研究

对栽培大麦（ＨｏｒｄｅｕｍｖｕｌｇａｒｅＬ．品种“Ａｒｕｐｏ”）与纤毛鹅观草（Ｒｏｅｇｎｅｒｉａｃｉｌｉａｒｉｓ（Ｔｒｉｎ．）Ｎｅｖｓｋｉ）属间杂种后代Ｆ５和回交后代ＢＣ１Ｆ４（以“Ａｒｕｐｏ”作回交亲本）的不同类型株系与其双亲的幼根、幼芽、幼穗、幼嫩籽粒分别进行了酯酶、过氧化物酶同工酶分析。结果Ｆ５和ＢＣ１Ｆ４各株系的酯酶同工酶、过氧化物酶同工酶酶谱具有母本“Ａｒｕｐｏ”全部或绝大多数酶带,父本Ｒ．ｃｉｌｉａｒｉｓ的１～３条酶带和数量不等的双亲所没有的新酶带,也出现酶带的减少。结果表明,纤毛鹅观草的遗传物质已稳定地遗传给了其自交和回交后代。酶谱变异与植株习性出现一定程度的关联。由于在不同时期内结构基因的表达起不同作用,因此,在用同工酶分析法鉴定易位系时,最好不同的器官采用不同的酶类或一种同工酶多时期连续分析。     

对用球茎大麦法诱导的大麦加倍单倍体及其后代表现的研究

用栽培大麦１０个品种间杂交组合的Ｆ１代与球茎大麦３个品系杂交,获得胚乳退化的杂效种子４８６７粒,解剖出幼胚２７６２个,再生植株４７６棵,成活植株３８２棵,加倍单倍体结实植株１２９棵,并对这１２９棵植株进行了后代观察。结果表明,杂交结实率可达９６。０％;再生植株加倍处理结实率在与球茎大麦ＰＢ１的组合中平均为６５。６％,与Ｃｂ２９２０／４的组合中平均为６１．３％,与２ｘ的组合中平均为２．９％。     

苏联球茎大麦有利基因引入普通小麦的研究

本研究从1979年开始,用抗病性较强的苏联球茎大麦(4x)为父本,普通小麦品种中国春(6x)为母本进行属间杂交,经离体培养杂种幼胚,获得了属间杂种(F_1)。杂种自交不育,用秋水仙素加倍亦不成功,而以中国春5B单体与之回交,获得回交一代(BC_1F_1)。杂种F_1形态为两亲的中间型,其花粉母细胞染色体数在24—30条之间。BC_1F_1代杂种的形态与F_1相似,染色体数在45—49条之间(其中大多数细胞终变期有20—21个二价体和3—7个单价体)。BC_1F_1代自交或回交均有部分结实。以后各代继续自交分离;于1985—1986年,分离出6个异源二体附加系(2n=22Ⅱ)和异源八倍体(2n=28Ⅱ)以及若干个与母本形态有明显差异的整倍体杂种后代(2n=21Ⅱ)。这些整倍体和非整倍体后代中,有2个附加系的蛋白质含量较高(22.30％和20.37％);在整倍体后代中有两个株系与其父本一样对小麦黄花叶病(WYMV)具有抗性,而其母本与浙江省当前推广的小麦品种均不抗病,说明球茎大麦抗黄花叶病基因可能已导入母本中国春小麦。     

谷子三体系列的建立

以谷子（Ｓｅｔａｒｉａ ｉｔａｌｉｃａ （Ｌ．） Ｂｅａｕｖ．）四倍体为母本、二倍体为父本杂交。在２１００ 个杂交后代中得到５ 株三倍体。对三倍体植株授以二倍体花粉,将收获的种子播种后,从所培育的植株中获得９ 种三体共２８３ 株。其中８ 种具有明显的形态特征,只有三体Ⅳ植株形态与二倍体非常相似     

小麦返白系与不同基因型小麦品种杂交后代IPO表达的研究

以小麦返白系和对照矮变１号以及返白系与各不同生态类型的冬性、半冬性、春性小麦的杂交、回交Ｆ１、Ｆ２代为材料,研究这些不同基因型品种在返白期间过氧化物酶同工酶（ＩＰＯ）基因表达模式的动态变化特点。结果表明,在返白期间以返白系为母本的各杂交、回交品种的白化苗中,ＩＰＯ的个别酶分子表现了可逆的基因阻遏和去阻遏的表达现象。这种表达特点在正、反杂交后Ｆ１代中表现一致,从遗传模式上分别属于质－核互作型的分子遗     

普通小麦×大麦杂种后代细胞遗传学研究

普通小麦×大麦杂种与普通小麦回交,产生了具有普通小麦细胞质带有部分大麦细胞核的普通小麦－大麦属间杂种后代,对其连续多年套袋自交,测交、细胞学鉴定和定向选择,从自交后代群体中筛选出一部分异附加系、异代换系和易位系街人有大麦某些特性的小析类型,并系统地对本和二体附加系自交后代染色体的分离行为作了遗传分析。结果表明：２ｎ＝４３的单体附加标株自交分离出单体附加的频率为２５．６％,二体附加的频率为１．２％;     

棉属种间高代系的过氧化物酶同工酶研究

利用薄层等电聚焦方法,对已稳定遗传２０代的棉属陆地棉（Ｇｏｓｓｙｐｉｕｍ ｈｉｒｓｕｔｕｍ ）×中棉（Ｇ．ａｒｂｏｒｅｕｍ ）种间高代系蕾期真叶及花药中的过氧化物酶同工酶进行研究,结果表明：１．同一棉种的不同品种,其过氧化物酶同工酶基本相同,同一染色体组的不同棉种,其过氧化物酶同工酶存在一定的差异,不同染色体组的棉种,其过氧化物酶同工酶存在显著的差异;２．高代系的同工酶谱与母本“科遗２号”相似,而与父本中棉“完紫”具有较大的差异     

以小麦叶片过氧化物酶同工酶pI6.1酶带为生化标记研究小麦在各生长期对白粉病的敏感性(英文)

小麦白粉病以其多发性、普遍性成为世界各地小麦生产的主要病害之一。在研究抗病品种对白粉病菌侵染的抗病机理中,采用等电聚焦凝胶电泳技术对抗、感白粉病小麦品种的叶片过氧化物酶同工酶酶谱进行的比较发现：两者的ｐＩ６．１酶带（位于等电聚焦凝胶电泳酶谱ｐＩ６．１）从拔节期至田间发病期之间的表现水平有很大差别。可以将其视为区别抗、感白粉病品种的特征性酶带。实验采用功能叶片（Ｆｉｇ．１）,对５０个小麦品种品系、抗、感病品种间４个组合的正反交Ｆ１代、１１９株Ｆ２代、６５株抗病品种／感病品种／／感病品种的回交一代（ＢＣ１）材料,在ｐＨ５～８范围内进行过氧化物酶同工酶的等电聚焦凝胶电泳分离。胶片于联苯胺染色液中显色。抗病品种中,ｐＩ６．１酶带在小麦全生育期均有较强的活性,染色后着色深,多属一级酶带;感病品种中,ｐＩ６．１酶带在拔节之后变得模糊不清、甚至消失踪迹,多为三级、零级酶带;然而、感染白粉病之后酶活性重新表现,并再次回升为一、二级酶带（Ｔａｂ．１）。此结果在五个年份中均能很好地重复（Ｔａｂ．２）。抗、感病品种间正反交Ｆ１代的ｐＩ６．１酶带均正常（Ｆｉｇ．２）,证明：ｐＩ６．１酶带的活性是核基因的表达行为。进而在拔节期至发病     

组织培养与普通小麦异源易位系选育

以中国春小麦品种中８６０１、澳大利亚栽培小麦品种Ｓｕｎｓｔａｒ、Ｍｉｌｌｅｗａ作母本,与抗大麦黄矮病毒病（ＢａｒｌｅｙＹｅｌｌｏｗＤｗａｒｆＶｉｒｕｓ,简称ＢＹＤＶ）的小麦－中间偃麦草异附加系Ｌ１杂交,取杂种的幼胚和幼穗作离体培养,获得大量再生植株。经酶联免疫吸附分析（ＥＬＩＳＡ）、限制性内切酶长度多态性分析（ＲＦＬＰ）、染色体数目的检查和田间抗性鉴定,在再生植株回交后代中获得了抗ＢＹＤＶ的杂合易位株,经自交和花药培养纯合,选育出Ｄ１０９１、Ｄ１０９４、Ｄ１６５８、ＴＣ５、ＴＣ６、ＴＣ７等一批抗性稳定或基本稳定的普通小麦选系。以白黑麦６Ｒ二体附加系为抗源,与严重感染白粉病的陕７８５９杂交,经幼胚培养在再生植株回交后代中筛选到白粉病免疫的普通小麦杂合易位系。研究结果表明：在小麦远缘杂交中,组织培养可以作为导入外源基因产生易位的手段之一加以利用。     

利用phlb突变体创造普通小麦—簇毛麦６ＶＳ端二体代换系

用中国春phlb突变体（C.S.phlbphlb)与普通小麦－簇毛麦６Ｖ（６Ａ）异代换系（Ｓub.6V)杂交,再用phlb突变体与Ｆ１回交,在高配对植株中筛选出一个６Ｖ染色体发生变化的植株,编号为ＬＶ０２,用染色体Ｃ－分带和荧光原位杂交技术,对ＬＶ０２株系的后代进一步鉴定,在ＢＣ１Ｆ２中筛选鉴定出１株编号为ＬＶ０２－０１的植株,该株含有４０条普通小麦染色体,１条簇毛麦６Ｖ染色体和１条６Ｖ短臂端着丝粒染色体,在ＬＶ０２－０１的分离后代中用同样技术鉴定出８株普通小麦－族毛麦６ＶＳ端二体代换系。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.