杨属派间核型比较研究

对杨属五派代表种的核型进行了分析,各代表种核型公式如下:欧洲山杨(白杨派)2n=2x=38=21m(2SAT)+4sm+13st(1SAT);小叶杨(青杨派)2n=2x=38=1M+26m(1SAT)+8sm(1SAT)+1st+2t(1SAT);大叶杨(大叶杨派)2n=2x=38=2M+22m+8sm+6st;胡杨(胡杨派)2n=2x=38=2M+23m+3sm+10st(2SAT);箭杆杨(黑杨派)2n=2x=38=3M+29m(2SAT)+5sm+1st。杨属派间核型差异主要表现在中部与次中部着丝点(M,m)和近端部与端部着丝点(st,t)染色体数目上。白杨派和胡杨派具较多的st、t染色体,核型不对称系数比其它派高。按Stebbins理论白杨派和胡杨派属进化类型。     

三倍体杨树核型分析

对4种三倍体杨树核型进行了比较分析,三倍体毛白杨核型为：2n=3x=57=1M 31m 10sm 15st;三倍体I-214为：2n=3x=57=2M 33m(2SAT) 10sm(1SAT) 10st(3SAT) 2t;三倍体武黑1号为：2n=3x=57=2M 38m(4SAT) 14sm(2SAT) 3st;三倍体廊坊3号为：2n=3x=57=35m 10sm(1SAT) 10st(2SAT) 2t(1SAT)。结果显示三倍体毛白杨核型与三倍体黑杨核型有显著不同,表明它们的基因组结构不同,起源各异。     

重楼属和延龄草核型的一致性

本文报道的重楼属3个种和变种与延龄草的核型基本一致,表明它们之间的亲缘关系很近,其核型简式为:延龄草(T. tschonoskii)2n=10=4m 2m(SAT) 2st(SAT) 2t(SAT) 1B;五指莲(Paris axialis)2n=10=6m 2t 2t(SAT) 2B;狭叶重楼(P. polyphylla var. stenophylla)2n=10=2m(SAT) 4m 2st 2t;小重楼(P.polyphylla var.minora)2n=10=4m 2sm 4t.     

紫苏属植物染色体数目和核型分析

通过对26份紫苏属材料进行染色体数目的观察,并对其1种(包括紫苏和白苏)及2变种材料各一份进行核型分析.结果显示,紫苏属植物染色体数均为2n=40,其核型公式分别为紫苏[P.frutescens(L.)Britton var.frutescens(zi-su)]2n=40=20m(2SAT) 10sm 10st;野生紫苏[P.frutescens var.purpurascens(Hayata)H.W.Li]2n=40=18m 14sm(2SAT) 8st;回回苏[P.frutescens var.crispa(Benth.)Deane ex Bailey]2n=40=10m(2SAT) 14sm 16st;白苏[P.frutescens(L.)Britton var.frutescens(bai-su)]2n=40-24m 12sm(2SAT) 4st.结果表明,紫苏属不同原(变)种植物的染色体数日相同,但在核型上存在一定的差异,其染色体核型为首次报道.     

云南淡黄花百合10居群核型研究

对云南淡黄花百合 10个居群核型进行了研究 ,结果如下 :普洱居群 2n =2x =2 4 =4m(4SAT ) 8st (1SAT ) 12t;大湾居群 2n =2x =2 4 =4m (4SAT ) 4sm (1SAT ) 6st 10t ;宝山居群 2n =2x =2 4 =4m (4SAT ) 4st (1SAT ) 16t ;元阳居群 2n =2x =2 4 =4m (4SAT ) 8st(1SAT ) 12t;玉屏山居群 2n =2x =2 4 =4m (4SAT ) 4sm (1SAT ) 12st 4t;易门居群 2n =2x =2 4 =4m (4SAT ) 2sm 14st (1SAT ) 4t ;峨山居群 2n =2x =2 4 =4m (4SAT ) 2sm 14st(1SAT ) 4t;老鹰地居群 2n =2x =4m (4SAT ) 2sm 14st (1SAT ) 4t;双柏居群 2n =2x =2 4 =4m (4SAT ) 12st (1SAT ) 8t;牟定居群 2n =2x =2 4 =4m (4SAT ) 8st (1SAT ) 12t。研究表明各居群的核型都属于Stebbins的 3B型 ,不同居群间存在染色体类型和随体染色体的多型性 ,同时还发现了B染色体和 4倍体染色体数目变异 ,本文最后讨论了云南淡黄花百合种内居群间核型分化的原因。     

百合科六属十五种植物的细胞学研究

本文对云南西北部百合科6属15种的染色体和核型进行了报道。 (1)Clintonia udensis Trautv．et Mey间期核属于浓密分散型,前期染色体属于渐变型,分裂中期体细胞染色体2n=14=8m+4sm+2st(2SAT),核型不对称性属于2A型;(2)鹿药属四个种间期核属于复杂中央微粒型,前期染色体属于中间型,分裂中期体细胞染色体分别为Smilacina henryi(Baker)Wang et Tang,2n=36=12m+16sm+6st+2t(2SAT), 核型不对称性属于2C型;Smilacina fusca Wall., 2n=36=14m(2SAT)+12sm+10st(2SAT), 核型不对称性属于2B型; Smilacina tatsienensis(Franch．)Wang et Tang, 2n=36=22m+2sm+2st(2SAT), 核型不对称性属于2C型;Smilacina atropurpurea(Franch．)Wang et Tang,2n=36=18m+6sm(2SAT)+12st,核型不对称性属于2C型;(3)黄精属四个种的间期核属于复杂中央微粒型,前期染色体属于中间型,分裂中期体细胞染色体分别为Polygonatum kingianum Coll．et Hesml．,2n=30=12m(2SAT) +6sm+lst+2t, 核型不对称性属于2C型; Polygonatum cirrhifolium(Wall．) Royal,2n=30=10m+4sm+12st+4t, 3C型; Polygonatum curvistylum Hua, 2n=78=24m(2SAT)+14sm(6SAT)+40st, 核型不对称性属于3C 型; Polygonatum cathcartii Baker,2n=32=12m+6sm+10st+2t+2bs,核型不对称性属于2C型;(4)百合属,假百合属,豹子花属三个属的间期核和前期染色体形态相似,都属于复杂中央微粒型,前期染色体属于中间型,分裂中期体 细胞染色体分别为Lilium henricii Franch,2n=24=2m(2SAT)+2sm+10st+10t,核型不对称性属于3A型;Lilium bakerianum Coll．et Hesml．var． rubrum Stearn, 2n=24=4m (2SAT)+10st+10t(2SAT),核型不对称性属于3A型;Nomocharis bilouensis Liang 2n=24=2m(2SAT)+2sm+12st+8t,核型不对称性属于3A型;Nomocharis pardanthina Franch．,2n=24=4m(2SAT)+12st (2SAT)+8t,核型不对称性属于3A型;Nomocharis sauluensis Balf, f.,2n=24=4m(2SAT)+10st(2SAT)+10t,核型不对称性属于3B型;Notholirion campanulatum Cotton et Stearn2n=24=2m(2SAT)+2sm+14st(2SAT)+6t,核型不对称性属于3A型。     

百合属4种植物的核型研究

采用常规压片法对4种百合属植物野百合(L.brow n ii F.E.B row n ex M ie llez.)、兰州百合(L.d av id iiDuchartre var.un icolor(Hoog.)Co Hon.)、川百合(L.d av id ii Duchartre)、湖北百合(L.henry i B aker)进行了核型研究.结果表明,4种百合的染色体数目均为2n=24,核型除川百合为3A外,其余3种均为3B型.核型公式分别为:野百合2n(2x)=24=4m(2SAT) 2sm(2SAT) 4st 14t,兰州百合2n(2x)=24=2m(2SAT) 2sm 10st(2SAT) 8t 2T,川百合2n(2x)=24=2m(2SAT) 2sm 12st(3SAT) 8t,湖北百合2n(2x)=24=4m 18st 2t,其中湖北百合染色体核型为首次报道.通过比较发现,兰州百合与川百合的核型最为相似,亲缘关系相近;核型不对称性为兰州百合>川百合>野百合>湖北百合,以湖北百合的核型较为原始.     

五种国产木来木属（广义）植物的核型

对分布于我国的木来木属Cornus L．(广义)4个主要类群的5种植物进行了细胞学研究。结果表明,这5种植物的染色体数目和核型分别为：灯台树 C．controversa Hemsl．2n=20=2m+8sm+10st;红瑞木 C．alba L．2n=22=8sm+12st+2t;毛木来C．walteri Wanger．2n=22=8sm+14st(0-2SAT);山茱萸C.officinalis Seid. et Zucc. 2n=18=8m+l0sm(0-2SAT);四照花(变种)C．kousa var. chinensis Osborn 2n=22=2sm+6st(0-2SAT)十14t。     

中国毛茛属新分类群及其核型

新种R．shuichengensis L,Liao有两种核型类型,即基本型2n=2x=16=4m+2sm+10st(2SAT);杂合型2n=2x=16=4m+2sm+9st(1SAT)+1t(1SAT),其核型和近缘种R．trigonus Hand．- Mazz.核型相似,但其随体染色体短臂比后者更小而不同。新变种R．silerifolius var．dolicanthus L. Liao核型(2n=2x=16=4m+2sm+10st(2SAT)与原变种Var．silerifolius不同。根据形态和染色体的特征,我们认为本文中两个新分类群和R．Trigonus是国产毛茛组中x=8至x=7的过渡类群。     

五种国产Lai木属（广义）植物的核型

对分布于我国的Lai木属Cornus L.(广义）4个主要类群的5种植物进行了细胞学研究。结果表明,这5种植物的染色体数目和核型分别为：灯台树C.controversa Hemsl.2n=20=2m 8sm 10st;红瑞木C.alba L.2n=22=8sm 12st 2t;毛Lai C.waltari Wanger.2n=22=8sm 14st(0-2SAT);山茱萸C.officinalis Seib.et Zucc.2n=18-8m 10sm(0-2SAT);四照花（变种）C.kousa var.chinensis Osborn 2n=22=2sm 6st(0-2SAT) 14t.     

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).