大豆5个花叶病毒株系抗性基因的定位

以科丰 1号×南农 1138 2为亲本构建的RIL群体NJRIKY为材料 ,对群体进行了 5个SMV株系 (Sa、Sc 8、Sc 9、N1 、N3)的抗病性鉴定。结果表明 :大豆对 5个SMV株系的抗性均受一对显性基因控制。用Mapmaker 3 0进行连锁分析 ,发现Rsa与Rn1、Rn3和Rsc9均连锁 ,距离分别为 2 1 4cM、2 3 5cM和 35 3cM ;Rsc8只和Rn1连锁 ,距离为 35 8cM ;Rn1和Rn3之间的遗传距离最近 ,为 10 2cM。多点分析结果表明 :5个抗病基因的排列顺序和遗传距离为Rsc8 35 8cM Rn1 10 3cM Rn3 2 1 5cM Rsa 35 8cM Rsc9。根据RFLP、SSR标记分析结果构建了一套大豆遗传图谱 ,该图谱包含 2 2个连锁群、2 5 6个标记 ,总遗传距离为 30 5 0 9cM。将 5个抗病基因定位于N8 D1b W连锁群 ,有 3个RFLP标记和Rn1、Rn3都连锁 ,分别为A6 91T、K4 77I、LC5T。它们与Rn1、Rn3的距离分别为 15 0 4cM、17 82cM、15 37cM和 16 14cM、17 82cM、16 5 8cM。     

甜瓜抗白粉病基因SRAP分子标记筛选

以感白粉病甜瓜A120和抗白粉病甜瓜A119为亲本构建F2代分离群体,采用BSA和SRAP相结合的方法筛选与甜瓜抗白粉病基因相连锁的分子标记.结果显示,294条SRAP引物中有6条引物在抗病与感病池间表现出多态性;对8个高抗和8个高感单株进行扩增,引物me46em51和me3em6分别在高感单株中扩增出210 bp和205 bp的多态性条带,而高抗单株无此扩增带,与抗病、感病池结果一致.采用JoinMap3.0软件进行连锁分析,两标记与抗白粉病基因的连锁距离分别为18.2 cM和23.4 cM,初步推测本实验中甜瓜白粉病抗性为隐性多基因控制.     

白菜紫色性状RAPD连锁标记的筛选与染色体定位研究

以紫菜薹自交系95T2-5、大白菜自交系94S17-1及其F1、F2、BC1植株为材料,进行RAPD分析,从640个随机引物中筛选出2个引物S79和S123,分别能扩增出与紫色性状连锁的条带S79-934和S123-750。连锁分析发现,标记S79-934和S123-750与紫色基因间的遗传距离分别为13.73cM和18.65cM,并且位于紫色基因的两边。回收S79-934特异带,克隆转化并测序,比较分析表明其与大白菜1号染色体上已知克隆KBrH077A05的全序列(113253bp)有99%的相似性,初步推断控制紫色性状的主基因位于大白菜1号染色体上。     

葡萄无核基因定位与作图的研究

以UBC 269484和GSLP1569的序列为支点,设计合成了包括UBC 269和GSLP1在内的9条引物,以葡萄 有核亲本红地球和无核亲本红光无核的DNA为模板,对这9个引物进行筛选,结果GSLP1、39970524 5号引物和 39970524 6号引物在无核亲本红光无核上扩增出了特异标记GSLP1569、39970524 5 564、39970524 6 1538和 39970524 6 1200。用这3个特异引物在红地球、红光无核、无核白和红地球×红光无核杂交组合F1代163株杂 种的DNA样上进行PCR扩增,结果4个特异标记在F1群体中与无核主效基因共分离。4个特异标记也出现于所 用组合中无核基因原始供给者无核白上。这些标记和葡萄无核主效基因相连锁。用QTXb17遗传作图软件,对葡 萄无核主效基因S定位与作图,当P=0.01时,LOD值在32.7～46.4之间,置信界限在0.2～9.9之间。这4个 特异标记和无核主效基因S处于在同一连锁群,位于无核主效基因S的两侧,覆盖基因组12.3cM。特异标记 39970524 5 564、GSLP1569、39970524 6 1538、39970524 6 1200距S基因的遗传距离分别为0.6cM、1.2cM、 4.9cM和11.1cM。     

大豆曲茎性状的遗传分析和RAPD标记研究

曲茎遗传材料NG94-156与遗传背景不同的3个正常茎品种杂交,获得1个F2群体和2个重组自交家系(F7:8)。后代分离分析的结果表明,NG94-156的曲茎性状受两对隐性重叠基因控制。利用4个亲本和1个重组自交家系筛选260个RAPD随机引物,其中有1个引物S-506扩增出的多态性条带有较好的重复性。经过连锁分析,RAPD标记S-5061600与控制曲茎的基因的遗传距离为6.94 cM。     

栽培稻F_1花粉不育基因座S-α的分子定位

以栽培稻品种台中65及其等基因已不育系TISL4为材料,用RFLP和RAPD等技术,对F_1花粉不育基因座S－a定位。通过用RFLP和RAPD方法对亲本间进行多态性分析,发现亲本间的多态性很低,说明经多代回交后,在等基因系基因组中供体亲本的DNA片段所占的比例很小。通过连锁分析,将S－a定位在第1染色体上。S－a与分子标记CDO548、O11—1000、RG146和Y13－500之间的遗传距离分别为6.4cM、6.8cM、7.2cM和11.3cM。S－a基因座上S－a~i／S-a~j等位基因互作使携带S-a~j基因的花粉败育是寻致该F_2群体产生偏态分离的主要原因。     

小麦品种Triticum spelta album中抗条锈病基因Yr5的RAPD标记

共用520个10碱基随机引物对小麦抗条锈基因Yr5的近等基因系进行了RAPD分析,发现了3个特异性DNA片段S1496、S14181950与Yr5基因连锁,其中S1496761与Yr5基因紧密连锁,遗传距离为2．7cM。经对特异性DNA片段S1496 761进行克隆,测序,设计了PCR扩增用专化引物SC－S1496 761a和SC－S149676b,用该引物可扩增出与原RAPD引物扩增出的相似的特异DNA片段,由于该引物还可扩增出迁移率极为相近的另1条非特异带,在琼脂糖凝胶上难以分辨,需用聚丙烯酰胺凝胶电泳结合银染进行检测,经用F2分离群体及部分相关品种材料检测,已证明该标记的可靠性。     

人工合成甘蓝型油菜中花色与芥酸含量的遗传连锁分析

利用人工合成的甘蓝型油菜品系．No．2127-17(白花、有芥酸)与加拿大双低甘蓝型油菜品种Quantum(黄花、低芥酸)配制杂交组合。对亲本、F1、BC1、F2和DH(doubled haploid)5个世代的花色及芥酸含量进行分析,结果表明：花色受单基因控制,且白花对黄花为显性;芥酸含量仅表现出一对基因的差异且具有加性效应的遗传模式。花色和芥酸含量的连锁分析表明：白花与高芥酸紧密连锁．在DH群体中重组频率为5．8％。采用集团分离分析法(Bulked Segregant Analysis,BSA),从685条10个碱基的随机引物筛选到一个与黄花和低芥酸含量紧密连锁的RAPD标记S92-1400。在遗传图谱上黄花基因和低芥酸基因距离S92-1400标记的图距分别为2．2cM和5．4cM。     

亚麻抗锈病基因M4的特异分子标记

用520个10碱基随机引物对含有亚麻抗锈病基因M4的近等基因系材料NM4及其轮回亲本Bison进行RAPD分析,其中OPA18引物在NM4材料中稳定地扩增出特异的DNA片段。用Bison与NM4杂交产生的F2分离群体进行的遗传连锁性分析表明,RAPD标记OPA18432与M4基因紧密连锁,二者之间的遗传距离为2.1cM。将OPA18432片段回收,克隆和测序,成功地将其转化为SCAR标记。对不同抗源材料的扩增分析表明,该标记是M4基因的特异标记。目前这一标记已成功地应用于亚麻抗锈病基因M4的分子标记辅助选择育种。     

利用分子标记定位农垦58S的光敏核不育基因

对农垦５８Ｓ（Ｏｒｙｚａｓａｔｉｖａｓｐ．ｊａｐｏｎｉｃａ）／大黑矮生标记基因系ＦＬ２组合组建可育集团和不育集团,并以亲本为对照进行了ＲＦＬＰ、ＲＡＰＤ和双引物ＲＡＰＤ分析,结果第１２染色体上的一个单拷贝标记Ｇ２１４０与光敏核不育基因连锁遗传,二者间的遗传图距为１４．１ｃＭ（ｃｅｎｔｉｍｏｒｇａｎ）。在筛选过的１０４０个随机单引物和１９０个双引物中,仅引物ＯＰＡＵ１０扩增出与光敏核不育基因连锁的１．５ｋｂＤＮＡ片段,回收、克隆该ＤＮＡ片段并制备探针,将其转换成共显性的ＲＦＬＰ标记并命名为ＯＰＡＵ１０１５００。分离群体连锁分析表明该标记与标记Ｇ２１４０紧密连锁,将农垦５８Ｓ的一对光敏核不育基因定位于第１２染色体上。     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).