不同花色紫斑牡丹的CDDP体系优化及其遗传多样性分析

利用CDDP（ Conserved DNA derived Polymorphism）分子标记方法,对47个不同花色紫斑牡丹品种的基因组DNA进行遗传多样性分析。结果显示：（1）采用正交实验设计,对影响紫斑牡丹CDDP PCR反应的引物浓度、DNA模板浓度两因素进行优化,优化后紫斑牡丹CDDP PCR反应体系为：总反应体系20 μL,其中包括2×Es Taq MasterMix酶（含染料）10 μL,10 pmol/μL引物1.5 μL,15 ng/μL DNA模板4 μL,ddH₂O 4.5 μL。（2）21条引物中,有19条产生了清晰的条带。19条引物共扩增出112条带,其中多态性条带 97条,占总条带数的 86.61％,多态性比例高。（3）UPGMA聚类显示,47个紫斑牡丹品种的聚类大体按照花色聚类,品种间遗传相似系数值在0.72~0.95,说明品种间相似度高,差异程度小。研究表明,CDDP分子标记方法适用于紫斑牡丹遗传关系分析,且特异条带的产生为深入研究紫斑牡丹品种鉴别提供理论依据。     

烟草种质资源遗传多样性的IRAP和ISSR标记比较分析

采用IRAP和ISSR两种分子标记方法,对国内外28份烟草种质资源进行聚类分析,并对两种方法的结果予以比较。结果如下：（1）用IRAP方法对供试材料进行PCR扩增,共得到214条条带,其中187条具有多态性,多态性比率达87．4％。当L1取值0．495时,可将28份材料划分为3个类群;L2取值0．34时,又可将第3类群划分为3个亚类群和3个单一品种组成的独立个类;（2）用ISSR方法进行PCR扩增时,共得到334条条带,其中250条有多态性,多态性比率为75％。当L1取值0．41时,可将28份烟草种质划分为2个类群和2个独立个类Coker176、BaSmaUovina,第一类群（Ⅰ）为来自美国的两个品种RG11和K730,其它24个品种为第二类群（Ⅱ）;（3）IRAP和ISSR两种方法的相关系数为0．823（r0．01=0．478）,说明这两种方法的结果高度相关,均可用来进行烟草种质资源遗传多样性的分析。用IRAP方法得到的品种间遗传相异系数（GD）平均为0．423,高于ISSR方法,而且条带更稳定、多态性比率更高,更易揭示不同品种材料的遗传差异。     

牡丹开花相关SWEET家族基因生物信息学与表达模式分析

为了揭示SWEET家族基因在牡丹开花过程中的作用,该研究以‘洛阳红’牡丹花瓣转录组数据库为基础,利用生物信息学方法对SWEET家族基因进行鉴定和分析。结果表明:(1)实验共得到10个具有完整开放阅读框的牡丹SWEET基因。(2)牡丹SWEET家族成员蛋白等电点、消光系数等差别不大,其中5个牡丹SWEET基因编码的蛋白为不稳定蛋白;亚细胞定位预测这10个牡丹SWEET基因编码的蛋白均定位在细胞膜;进化树分析显示,牡丹SWEET基因与拟南芥亲缘关系更近;结构分析表明,牡丹SWEET蛋白结构在进化过程中非常保守,这10个牡丹SWEET蛋白同时具有5个相同的Motif且均含2个MtN3 saliva结构域。(3)可溶性糖含量分析显示,从小风铃期到盛花期,牡丹花瓣中蔗糖含量不断降低,果糖和葡萄糖含量不断升高,均在盛花期达到峰值。(4)qRT-PCR分析显示,PsSWEET4盛花期表达量是小风铃期的34倍,PsSWEET8盛花期表达量是小风铃期的60倍。结合这2个基因表达与进化关系及可溶性糖变化值,初步推测PsSWEET4和PsSWEET8在开花过程中可能通过调控果糖、葡萄糖的转运而间接调控开花过程;该结果为进一步研究PsSWEET基因在牡丹生长发育过程中的功能奠定了基础。     

蓝浆果花冠形态特征及其与果实横径相关性的分析

对兔眼蓝浆果（Vaccinium ashei Reade）、北方高丛蓝浆果（V.corymbosum L．）和南方高丛蓝浆果（V.corymbosum hybrids）3个品种群及南方高丛蓝浆果实生系的花冠长度、花冠宽度、花冠长宽比和花冠口径大小等特征进行了测定和比较,并研究了花冠形态特征参数与果实横径的相关性。研究结果表明,蓝浆果不同品种群间和同一品种群内不同品种间的花冠形态特征参数差异较大;依据花冠形态特征参数,可将供试的兔眼蓝浆果和南方高丛蓝浆果各品种及南方高丛蓝浆果各实生系初步划分为4种类型,将供试的北方高丛蓝浆果各品种划分为3种类型。此外,只有南方高丛蓝浆果各品种及其实生系的果实横径与花冠宽度相关性显著（P〈0．05）,相关系数分别为0．639和0．324。     

芍药属牡丹组革质花盘亚组的系统演化探讨

芍药属牡丹组革质花盘亚组全部原产中国,它们对中国、日本、美国和欧洲的栽培牡丹品种影响甚大。作者在对本亚组9种牡丹(含3个亚种)形态学比较分析的基础上,结合花粉、染色体、蛋白质和DNA水平上的研究证据,提出了本亚组的系统演化的可能途径为:(1)卵叶牡丹→银屏牡丹→矮牡丹→圆裂四川牡丹→四川牡丹,(2)卵叶牡丹→凤丹→紫斑牡丹→太白山紫斑牡丹。另外作者对肉质花盘亚组的系统演化地位也进行了讨论。     

‘挽春’（Paeonia rocldi‘Wan Chun’）——中国西北紫斑牡丹品种群中的一个优良品种

紫斑牡丹品种群是中国的主要牡丹品种群之一。文中描述了一个优良紫斑牡丹品种‘挽春’（Paeonia rockii‘Wan Chun’）的特征、习性和表现,该品种在紫斑牡丹品种群中具有代表性。紫斑牡丹品种可用于园艺观赏、经济林营造、荒山绿化以及荒漠治理。根据多年的调查和相关文献,按照紫斑牡丹品种的生长适应程度和引种栽培难易程度,将中国有可能引种栽植紫斑牡丹品种的地区划分为4类。介绍了各类地区在引种栽培方面需要注意的关键技术措施,分析了紫斑牡丹品种向全国各地推广过程中存在的问题,并提出了建议。     

不同品种牡丹对丛枝菌根真菌群落结构的影响

对山东菏泽赵楼牡丹园栽培的不同品种牡丹(Paeonia suffruticosa)根围丛枝菌根(ar-buscular mycorrhiza,AM)真菌孢子密度、种属构成、种丰度、分布频度、物种多样性指数及其物种组成相似性等进行了研究.结果表明:不同品种牡丹根围AM真菌的种属构成、种丰度和分布频度等均不相同,其中,从‘凤丹'和‘赵粉'根围中各分离到10种AM真菌,从‘乌龙捧盛'和‘洛阳红'根围中分离到9种,从‘胡红'根围中分离到8种;‘凤丹'根围AM真菌孢子密度最高,为59个·50 g-1土,‘胡红'最低,为47个·(50 g)-1土;‘赵粉'的物种多样性指数最高(1.89),‘胡红'最低(1.71).‘凤丹'和‘胡红'的菌根侵染率最高,为63.6%,‘乌龙捧盛'最低,为52.7%.不同牡丹品种之间AM真菌种类组成的相似性系数在0.71～0.95,其中‘乌龙捧盛'和‘凤丹'的相似性系数最高(0.95),而‘胡红'与‘洛阳红'的相似性系数最低(0.71).牡丹基因型能改变AM真菌群落结构特征.     

基于ITS和matK基因对牡丹组序列分析及其亲缘关系的研究

以芍药属牡丹组全部9个野生种、5个紫斑牡丹栽培品种及3个中原牡丹品种为试材,进行核糖体内转录间隔区（ITS）和叶绿体成熟酶K （matK）基因片段测序分析,探讨ITS和matK序列为牡丹组所有野生种种间关系提供分子证据。从GeneBank中选取了1个牡丹及3个外类群芍药、川赤芍和草芍药的ITS及matK序列。对试验样品进行DNA提取、PCR扩增并双向测序得到44条序列,人工校正后将所得44条序列进行比对;计算碱基组成频率、变异位点、简约信息位点数、转换/颠换比率、种内及种间遗传距离,以邻接法进行系统发育分析。结果表明,牡丹组所有个体ITS序列长度在750~800 bp,含有86个多态位点,74个简约信息位点,转换/颠换比率（R）为1.2;而matK序列含有20个简约信息位点,转换/颠换比率（R）为1.7。ITS序列分析将牡丹组野生种分为两大枝,稷山牡丹、紫斑牡丹、卵叶牡丹和杨山牡丹聚为一枝,狭叶牡丹、滇牡丹、黄牡丹和大花黄牡丹聚为另一枝,这两枝分别与革质花盘亚组和肉质花盘亚组相对应,而四川牡丹位于革质花盘亚组最底端,支持前人研究将四川牡丹归为革质花盘亚组。matK序列分析的牡丹组野生种间遗传距离结果不理想,未能清晰的表明野生种之间的亲缘关系。由此说明,ITS序列更适合牡丹组野生种间亲缘关系的研究分析。     

动态吸附与气相色谱-质谱（GC-MS）联用分析密蒙花（醉鱼草科）的挥发性花香成分

采用气相色谱-质谱联用技术对动态吸附法收集的密蒙花（Buddleja officinalis）花香成分进行了分析,并用气相色谱面积归-化法对各成分进行了定量。从密蒙花中分离出16个挥发性成分,定性定量出其中的11个,占挥发性成分总量的95．44％。其中丁基醋酸乙酯（81．57％）、苯甲醛（4．92％）、3-已烯-1-醇（3．26％）、欧洲丁香醛（2．34％）和芳樟醇（1．05％）为主要成分。该研究阐明了自然条件下密蒙花的花香成分及组成,其结果为今后定向创新醉鱼草属新香型观赏品种提供了科学依据。     

铜陵牡丹和垫江牡丹的同工酶分析

采用垂直板聚丙烯酰胺凝胶电泳技术,对铜陵牡丹和垫江牡丹进行过氧化物酶（POD）和酯酶（EST）同工酶的测定分析。结果显示,两个品种牡丹的POD同工酶酶谱共栓出7条酶带,其中铜陵牡丹分离带为7条,垫江牡丹为3条,铜陵牡丹多出4条特有酶带,且活性较强;EST酯酶同工酶中,两种牡丹共有酶带为5条,活性上略有差异,铜陵牡丹特有2条酶带,垫江牡丹特有1条酶带。     

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.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细