利用RAPD标记评价小豆种质遗传多样性

本研究利用10个RAPD引物对180份小豆种质的基因组DNA进行扩增,共扩增出44条带,其中35条具有多态性,比例为79.5%,平均每个引物扩增出3.5条多态性带;平均遗传距离为0.274,变异幅度为0.05～0.60,平均遗传多样性指数为0.692;基于RAPD标记,把180份小豆种质聚类划分为4个组群,该组群的划分与小豆的生态地域性似乎不存在明显的相关性.     

利用AFLP标记鉴定小豆种质遗传多样性

利用11对AFLP引物对106份小豆种质的基因组DNA进行扩增,共扩增出603条清晰可辨的带型,其中208条具有多态性,比例为34.5%,平均每对引物扩增出18.9条多态性带.基于AFLP标记,把106份小豆种质聚类划分为4个组群,该组群的划分与小豆的生态地域性存在一定的相关性.     

利用RAPD标记评价小豆种质遗传多样性

本研究利用10个RAPD引物对180份小豆种质的基因组DNA进行扩增,共扩增出44条带,其中35条具有多态性,比例为79．5％,平均每个引物扩增出3．5条多态性带;平均遗传距离为0．274,变异幅度为0．05－0．60,平均遗传多样性指数为0．692;基于RAPD标记,把180份小豆种质聚类划分为4个组群,该组群的划分与小豆的生态地域性似乎不存在明显的相关性。     

利用AFLP标记鉴定小豆种质遗传多样性

利用11对AFLP引物对106份小豆种质的基因组DNA进行扩增,共扩增出603条清晰可辨的带型,其中208条具有多态性,比例为34．5％,平均每对引物扩增出18．9条多态性带。基于AFLP标记,把106份小豆种质聚类划分为4个组群,该组群的划分与小豆的生态地域性存在一定的相关性。     

野生小豆种质资源植株形态性状多样性分析

对来自中国、日本、韩国、缅甸4国的55份野生型、40份半野生型小豆种质资源植株形态性状的多样性进行分析,结果表明,野生型小豆与半野生型小豆在株高、平均成熟期、子粒颜色、百粒重等性状方面有明显的差别。95份小豆种质资源通过聚类分析,截值为1.488时可划分为5大类群。来源于缅甸和中国的野生型小豆种质各聚为1个类群,韩国和日本的种质混聚为3个类群。缅甸种质具平均成熟期长、茎秆粗、主茎分枝数多、百粒重轻等特点。中国贵州野生型种质植株较高、茎秆较细、单荚粒数较多、平均成熟期较长。日本野生型种质具有丰产特征。日本和韩国的半野生型小豆,平均成熟期较其他类群早、百粒重高、明度指数高。     

小豆种质资源农艺性状综合鉴定与评价

通过田间观测和室内分析,对来自全国各生态区的262份小豆优异种质资源连续2年进行了农艺性状鉴定及综合评价。结果表明:262份小豆微核心种质资源在考察的16个形态学性状中均具有丰富的遗传变异类型;不同年份间生态环境尤其是光照条件对小豆农艺性状影响较大;主成分分析确定了3类影响因子,表明小豆资源的选育要集中在生长势良好(生育日数较短、株高较矮),单株荚数和单荚粒数多的地方品种;聚类分析结果显示在相似系数为0.40时可将参试材料分为5大类群,各类群间性状差异明显;群体性状表现与地理来源之间没有直接的关系。     

我国小豆应用核心种质的生态适应性及评价利用

为提高我国小豆(Vigna angularis)应用型核心样本的育种利用效率,本研究通过两年两点的田间试验,分析了166份这些核心种质农艺性状的变异情况,明确了其生态适应性和可利用价值。结果表明,166份小豆核心种质在广西南宁均表现为直立生长,并能正常成熟收获,;在河北唐山仅有64.2%XX88份种质的小豆种质在河北唐山两年内均表现为直立生长,且有25份不能正常开花结荚。大部分数量性状年度间差异与生态环境有关,其中唐山的年度间差异不明显,而南宁的年度间均达到极显著差异,反映了小豆对生态环境、气候条件的较强敏感性。所有种质在南宁的生育期显著提前,而产量相关因子中,单株荚数、百粒重等均显著小于唐山。综合分析表明不同种质的生态适应性存在较大差异,说明选育广适性小豆品种是可能的。综合最终根据农艺性状的综合表现,分别筛选出适合南宁和唐山育种利用的优异种质共16份。筛选出适合南宁种植的绿豆种质8多少份,适合唐山种植的绿豆种质10多少份。     

小豆种质资源子粒淀粉和支链淀粉含量分析

对小豆主产区的325份种质资源的子粒总淀粉和支链淀粉相对含量进行了鉴定评价.结果表明:小豆子粒中总淀粉含量为44.79%～67.44%,平均为57.06%;支链淀粉相对含量为62.61%～98.94%,平均为82.24%;品种间差异均达极显著.筛选出总淀粉高于62.64%和支链淀粉相对含量高于93.57%的种质资源各16份、直链淀粉相对含量高于29.14%的种质资源13份.     

基于SSR标记分析小豆及其近缘植物的遗传关系

本研究利用87对SSR引物分析了80份栽培小豆(Vigna angularis)、22份野生小豆(V.angularis var.nipponensis)以及10份豇豆属(共7个种)近缘植物,旨在比较豇豆属不同种的遗传多样性,并分析种间的遗传关系.结果显示87对SSR引物在112份小豆及其近缘植物资源中共检测到667个等位变异.其中有75个、71个和82个SSR位点分别在栽培小豆、野生小豆和近缘植物中表现为多态.随机抽样分析发现,平均每SSR位点检测到的等位变异数目为近缘植物>野生小豆>栽培小豆,与多态信息含量(PIC)值一致,说明近缘植物及野生小豆中蕴含着丰富的遗传变异,是栽培小豆育种的重要基因来源.聚类分析显示,栽培小豆、野生小豆和近缘植物间的遗传分化比较明显,分别聚为三大类,其中栽培小豆的遗传背景与其生态环境相对应;近缘植物又可以分为三个亚类,亚类间的遗传距离与其亲缘关系相对应.本研究结果也说明利用SSR标记辅助豇豆属的种间分类是可行的.     

利用SSR分子标记检测黄淮夏大豆(Glycine max)初选核心样本的代表性

作物核心种质是用最小的样本代表其全部遗传资源的最大遗传多样性。为了检测大豆初选核心样本取样的代表性,本研究从黄淮夏大豆初选核心样本中,随机选取两个类群,其材料数分别为20份和14份;从保留种质的相应奥群中,分别随机选取6份和5份,共计45份材料,进行14个农艺性状和20对SSR引物的分析。对两组材料进行农艺性状聚类．保菌种质与初选核心种质聚在了一起;利用SSR分子标记数据聚类,也得到了相同的结果。初选核心样本两个类群材料的等位变异数分别为129个,136个;保留种质相应类群材料的等位变异分别为76个,71个;初选核心种质两个类群材料分别包合了整个资源86.00％和86．62％的遗传多样性。本研究为大豆核心种质构建及检测提供分子水平的依据。     

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.