贵州3种车前草的随机扩增多态性DNA(RAPD)亲缘关系分析

利用随机扩增多态性DNA(RAPD)技术对贵州车前草的3个种进行了分析,建立了它们的指纹图谱.从60个随机引物中筛选出的9个引物共产生94条DNA片段,大小分布在0.1～0.2kb之间,其中71个条带具有遗传多态性,约占总数的75.53％.平均每个引物扩增的DNA带数为10.44条.应用NTSYSpc软件进行聚类,将聚类结果转化为3种车前草之间的遗传关系树形图.结果显示,车前和平车前首先聚类,其Dice相似性系数为0.76,在三者中它们的亲缘关系较近;而大车前与它们的遗传相似性系数为0.56,亲缘关系较远.     

应用SRAP标记分析金丝瓜（Cucubitapepo L.）种质资源遗传多样性与亲缘关系

本研究应用SRAP分子标记技术对56份金丝瓜和32份南瓜属（包括西葫芦美洲南瓜、中国南瓜、印度南瓜）种质资源遗传多样性与亲缘关系进行分析。结果表明：（1）从285对SRAP引物中共筛选出50对多态性引物对供试品种基因组DNA进行PCR扩增,获得713条清晰可辨的标记,其中多态性条带634条,多态性比率达88.92%,说明出南瓜属种间遗传多样性较丰富;（2）在56份金丝瓜品种中,共扩增出586条清晰可辨条带,多态性条带350条,多态性比率为59.73%,说明金丝瓜品种间的遗传相似性较高;（3）通过分子聚类分析可将供试金丝瓜品种划分为5个亚类群。金丝瓜与西葫芦美洲南瓜的亲缘关系较近,与中国南瓜的亲缘关系较远,而与印度南瓜的亲缘关系最远;根据分子聚类分析结果证实初步鉴定应可以明确将金丝瓜划归为南瓜属中西葫芦美洲南瓜的一个变亚种。     

辣椒种质遗传多样性的RAPD和ISSR及其表型数据分析

用RAPDI、SSR分子标记及28个表型性状数据对辣椒属5个栽培种的13份材料进行了分析,结果表明:23条RAPD引物共扩增出209条带,平均每个引物扩增出9.09条,多态性位点比率为83.73%;16条ISSR引物共扩增出94条带,平均每个引物扩增出5.88条,多态性位点比率为79.79%.与RAPD相比,ISSR标记检测到的有效等位基因数(Ne)及Shannon多样性指数(I)、遗传离散度(Ht)和遗传分化系数(Gst)等遗传多样性参数都较大,多态性位点比例在亲缘关系较近的一年生辣椒(Capsicum annuum)种内较高,说明ISSR有更高的多态性检测效率,并且适合亲缘关系较近的种群间遗传多样性分析.基于RAPDI、SSR的聚类与基于表型数据的聚类之间存在极显著正相关,且都能将C.annuum与其它栽培种区分开来.     

RAPD和ISSR标记对水稻化感种质资源遗传多态性的分析

运用RAPD和ISSR技术分析水稻化感种质资源的遗传多态性。从供试材料中筛选到具有多态性的RAPD引物12条,ISSR引物7条。RAPD引物共扩增到85条清晰的多态性条带,多态性条带比率为69．4％。ISSR引物共扩增到34条清晰的多态性条带,多态性条带比率为53．0％。对两种标记结果进行UPGMA聚类分析,结果极其类似,呈极显著的正相关(r=0．74)。聚类结果表明,地理位置相近的品种聚为一类。部分具有较强化感作用潜力的水稻品种亲缘关系很近,表明控制其化感作用性状的基因可能是等位的相同基因。而部分化感作用潜力差异显著的水稻品种聚为一类,这是由于人类在长期高产品种的定向选择过程中,水稻化感作用性状不被注意而丢失,遗传基础日益狭窄的原因。     

利用AFLP技术分析丹顶鹤的亲缘关系

建立了丹顶鹤(Grus japonensis)AFLP分析体系,经筛选,利用28对选择性扩增引物构建了5对丹顶鹤AFLP亲缘关系分析图谱,共得到1 114个扩增条带,其中多态性条带551条,多态性比例为49.5%。每个引物组合扩增的条带数为20～66条,其中,引物E4M1扩增的条带最多,为66条;引物E6M1扩增的条带数最少,为20条。经统计分析,计算了各样品间的相似性系数在0.71～0.88之间,得到5对丹顶鹤的遗传距离,并构建了UPGMA聚类图,结果1号与2号、3号与4号鹤的亲缘关系较近,其余3对鹤(自然配对)亲缘关系较远。表明丹顶鹤具有识别亲缘关系的行为机制,丰富了丹顶鹤繁殖行为机制的研究内容,并为深入研究建立合理的散养丹顶鹤繁育体系提出了建议。     

贵州地方山羊品种的RAPD分析

用180条引物对黔东南小香羊、贵州白山羊、贵州黑山羊和黔北麻羊4个贵州地方山羊品种(种群),以及南江黄羊和波尔山羊进行RAPD分析,其中27条引物扩增出多态性图谱。这27条引物共扩增出281条带,多态带为115条,平均多态频率为40．92％(范围20％～80％);每条引物平均扩增条带为10．41条(范围4～16条);扩增带分子量在210～2800bp。贵州白山羊与贵州黑山羊之间的遗传距离指数(0．0605)最小,而波尔山羊与其他品种之间的遗传距离指数(0．1059～0．1488)最大。NJ法聚类结果显示,贵州白山羊与贵州黑山羊间的亲缘关系最近,其次为黔北麻羊,而黔东南小香羊与其他3个贵州地方品种的亲缘关系较南江黄羊还远。分析表明,黔东南小香羊在遗传上为一独立的品种;而贵州地方山羊品种间具有较近的亲缘关系,遗传变异较小,具有较高的遗传稳定性。     

利用SRAP标记分析海南旱稻地方品种的遗传多样性及其分子身份证的构建

利用SRAP标记对来自海南省的28份旱稻种质进行了亲缘关系分析。从255对引物组合中筛选出46对扩增条带清晰、多态性高的引物组合,并选用其中的18对引物组合对28份材料进行SRAP扩增,共扩增出180个条带,其中多态性条带160条,多态性比率为87.75%,平均每对引物组合产生10个条带和8.9个多态性条带。并且,运用UPMGA方法进行的聚类分析结果表明,供试旱稻种质的遗传相似系数范围为0.687 0-0.921 2,在遗传相似系数0.687 0处分为两大类群,第I类群全部为海南山栏稻种质,第Ⅱ类群为海南地方旱稻坡压和本研究组自育旱稻品种。对海南旱稻地方品种的划分表明,山栏稻种质间亲缘关系较近,海南地方旱稻坡压可能与籼型水稻种质具有一定的遗传相似性。此外,还构建了28份海南省旱稻种质的SRAP标记分子身份证,可为山栏稻种质的遗传亲缘关系,种质鉴定及新品种选育等方面提供依据。     

中国桑树选育品种ISSR指纹图谱的构建及遗传多样性分析

利用ISSR标记构建了24个选育桑品种的指纹图谱,用3种独立的方法（特殊的标记;特异的谱带类型;不同引物提供的谱带类型组合）可以有效地鉴别桑树选育品种,证明ISSR标记在桑树品种的鉴别方面是一个有效的工具和方法。17个ISSR引物共扩增出80条带,40条带具有多态性,占50．0％。24份选育桑树品种间平均遗传相似系数、Nei’S基因多样性（gene diversity）和Shannon’S信息指数分别为0．8731,0．1210和0．1942。桑树选育品种间的遗传多样性较低,说明中国选育桑品种间遗传距离较小,亲缘关系较近,。遗传基础较狭窄。UPGMA法聚类和PCA分析都清楚地显示了24个桑树选育品种的亲缘关系,聚类结果与桑树品种的系谱基本一致。     

桂西南早熟荔枝实生资源遗传多样性的ISSR分析

利用ISSR标记技术对83份早熟荔枝(品种)单株遗传多样性进行分析。筛选出多态性高的10条IS-SR引物,共扩增出128条DNA条带,其中多态性带107条,多态性百分率为83.59%,表明桂西南早熟荔枝实生资源遗传多样性较丰富;用NTSYS软件计算出这83份材料的DICE相似系数在0.64～0.95之间,遗传亲缘关系较近;用UPGMA方法构建分子树状图,在相似系数0.75时,可将栽培品种与桂西南早熟实生单株区分开。各地区资源混杂聚类在一起,不能按地区单独聚类。     

30个枣树种质资源遗传多样性的ISSR分析

取30个枣树品种进行ISSR分子标记分析,其扩增条带分别进行琼脂糖和聚丙烯酰胺凝胶电泳检测,以期获得不同产地品种之间的遗传多态性。从100条选择扩增的ISSR引物中筛选出17条扩增清晰、重复性和稳定性好的引物,选取其中8条扩增条带多态性强的引物进行遗传聚类分析。结果表明：（1）1％琼脂糖凝胶电泳和5％聚丙烯酰胺凝胶电泳检测扩增总条带数分别为72和127条,其中多态性条带分别为51条和113条,多态性条带比率（PPB）分别为70．8％和88．9％。（2）基于UPGMA软件对30个品种的遗传差异性分析表明,8个ISSR引物可以将枣树品种之间遗传差异明显区分开来。两种电泳检测方法相比较,聚丙烯酰胺凝胶电泳检测可获得较为精细的枣树品种间遗传图谱。其遗传相似系数范围在0．56～1．00之间,以0．62为最低遗传相似系数,可将30个枣树品种分成3个大类,6个亚类,为进一步研究枣树品种间分类、起源进化关系和分子辅助育种奠定基础。     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various