甘蓝型特高含油量油菜种质资源及主栽品种指纹图谱构建

本研究选择特高含油量资源7份,与中国各油菜主产区具有代表性的主栽品种16份,利用SSR多引物组合法开展指纹图谱构建研究。选择多态丰富、图谱清晰稳定且来自不同连锁群的引物28对,对所有材料进行指纹图谱分析,共获SSR指纹条带302条,其中多态性条带为279条,每引物所获条带6-16条,平均10.79条,平均多态率92. 38%,通过指纹图谱将所有材料有效地区别开来。用非加权类平均法（UPGAM）聚类分析显示：高油材料之间以及高油材料与主栽品种之间遗传距离均有较大差异,在遗传距离0.171处可将23份材料分成9个类群,其中7份高油材料分处4个类群,遗传距离差异显著;而其他8份主栽品种被分别聚类在另外5个类群中;所有材料间皆具有丰富的遗传多样性,其中高油材料与主栽品种间遗传差异更大。     

32个柿主栽品种SSR图谱构建及遗传变异分析

以32份柿主栽品种为试验材料,利用SSR标记技术构建其指纹图谱并进行遗传多样性分析。从78对候选引物中筛选出20对多态性高、稳定性好的引物作为核心引物,构建柿主栽品种SSR指纹图谱。结果显示:(1)20对引物在32份材料中共扩增出183条多态性条带,每对引物扩增出3～20条不等,平均每对引物扩增出9.15条,多态性比率为81.3%。各个位点的杂合度在0.410 3～0.914 3之间,平均为0.702 7。(2)8对引物在12个品种上具有特征带型,采用5对引物进行组合鉴定即可将32个柿品种完全区分开。(3)依据SSR带型特征,对每对引物生成的不同带型直接编号,简化柿SSR带型记录方法,并利用每个品种的带型编号,建立其DNA指纹图谱,结果表明,核心引物组合法比特征谱带法更适用于构建中国柿主栽品种DNA指纹图谱。(4)根据系统聚类分析将32个柿主栽品种分为两大类,品种间的亲缘关系与地理来源具有一定的相关性。     

SSR标记在毛木耳种质资源遗传多样性研究中的应用

本研究利用基于毛木耳全基因组开发的SSR标记对27份毛木耳菌株（野生14株、栽培13株）的遗传多样性进行分析。首先随机选取3个菌株（2个野生菌株、1个栽培菌株）的DNA为模板,从144对SSR引物中筛选出扩增条带清晰、稳定性强、多态性丰富的引物24对。24对SSR引物共检测到116个多态性SSR片段,每对引物的多态性片段有3-7个,引物平均检测效率为4.83个,Shannon’s遗传多样性指数范围是0.866-1.885,多态性位点比率100%。供试菌株遗传相似系数范围是0.618-0.971,说明毛木耳种质资源具有丰富的遗传多样性。野生菌株与栽培菌株间平均遗传相似系数分别为0.746、0.779,说明毛木耳野生菌株遗传多样性更为丰富。经聚类分析,在遗传相似系数为0.680时,可将供试菌株分为无色（白色）类群Ⅰ和有色（浅黄色到红褐色）类群Ⅱ。遗传相似系数为0.704时,可将供试菌株中栽培菌株和野生菌株明显区分（14株野生菌株均在类群Ⅱ-2中,13株栽培菌株分别在类群Ⅰ和Ⅱ-1中）。本研究表明基于全基因组的SSR标记能从分子水平上揭示各菌株间的遗传差异,丰富毛木耳遗传多样性的研究手段,并为进一步进行毛木耳的品种选育、遗传学研究等提供有力手段。     

利用SSR标记鉴定香菇单核体及杂交后代

【目的】研究简单重复序列(Simple sequence repeat,SSR)分子标记方法用于香菇原生质体单核体、孢子单核体及其杂交后代的分离和鉴定。【方法】利用基于香菇全基因组序列信息开发的SSR标记,分析由香菇品种"L808"双核菌丝制备的原生质体单核体、孢子单核体及其杂交后代的SSR指纹。【结果】对制备的原生质体单核体的鉴定中,在不经过杂交配对的情况下,鉴定出"L808"的两种不同极性的原生质体单核体,其分离比例为191:1,该鉴定结果得到SSR标记、随机扩增多态性DNA(Random amplified polymorphismic DNA,RAPD)标记及传统方法的验证。另外,开发的香菇SSR标记还能以多位点组合的方式,用于对孢子单核体及其杂交后代的鉴定。【结论】应用SSR标记可加快香菇单核体的制备进程,并提高鉴定单核体及相关杂交菌株的准确性,促进香菇遗传育种研究。     

基于SSR标记分析大豆疫霉根腐病抗源的遗传多样性

丰富的遗传多样性可为大豆育种提供宽阔的遗传基础,本研究基于35对SSR标记,对60份东北地区大豆疫霉根腐病抗性品种进行了遗传多样性分析,共检测到189个等位基因,平均每个位点等位变异数5.4个,多态性信息含量指数(PIC)为0.1550~0.8195,平均为0.6636;遗传相似系数的变异范围为0.31~0.74。利用5对高多态性SSR引物构建了60份抗性材料的指纹图谱,这5对SSR引物构建的指纹图谱可以将60份疫霉根腐病抗性材料逐一区分开。采用NTSYS2.10基于遗传距离的聚类分析,将60份抗性材料分为7个类群,其中78.33%的抗性品种(系)的遗传相似系数在0.45~0.74间,表明遗传差异相对较窄,品种间遗传多样性水平较低。聚类分析与群体遗传结构分析结果有部分重合,均反映出不同地区的抗性材料间存在一定的渗透和交流。     

香菇主要栽培菌株遗传多样性的AFLP分析

采用AFLP技术分析了收集到的31个主要香菇栽培菌株的DNA多态性。采用6对引物共扩增得到了443条DNA带,其中共有条带为189条,多态性比率为57.34%,说明收集到的香菇菌种具有一定的遗传多样性,它们之间存在一定的遗传差异。用平均连锁聚类法构建了所有样本的遗传相关聚类图,以0.80的相似性为切割点,31个菌株可分成4个类群,类群Ⅰ主要由上海农科院食用菌研究所和福建三明真菌研究所提供的香菇菌种组成,类群Ⅱ全部由收集到的日本栽培品种组成,类群Ⅲ由浙江庆元与福建三明真菌所的菌种组成,类群Ⅳ为上海农科院食用菌所的7402。本研究为香菇遗传信息数据库的建立奠定基础,为优良品种选育和亲缘关系的研究提供分子生物学依据。AFLP技术通过不同菌株的指纹图谱的不同能够有效分辨其基因型,可为香菇的栽培菌株质量监测和菌种鉴定提供快速有效的技术手段,从而为规范食用菌菌种生产管理提供科学依据。     

红麻微卫星DNA标记指纹图谱的构建

DNA指纹图谱对新品种选育、种质资源保存和管理具有重要的意义。然而,利用SSR标记构建红麻DNA指纹图谱的研究仍十分有限。在本研究中,利用课题组开发并筛选出的131对SSR引物,分析不同来源的96份红麻种质资源,包括红麻品种审定的区试对照品种福红952。结果表明,131对引物共扩增出375条带,平均每对引物扩增出2.6条带。以遗传相似系数0.614为切割线时,可以分为2个类群,52个为类群P1,44个为类群P2;以遗传相似系数0.710做切割线,可分为5个亚群。利用这131对引物标记所得的数据成功绘制了一份85个品种独特的指纹图谱,其中福红952可被HcEMS238引物特异识别。其他11份因存在遗传相似性高的现象,未被识别。上述结果为红麻品种的真实性鉴定及遗传多样性分析提供依据。     

中国35个苦荞审定品种EST-SSR指纹图谱构建与遗传多样性分析

核心引物对种质资源遗传多样性分析、品种鉴定、指纹图谱构建等研究具有重要价值。本研究以35个苦荞（Fagopyrum tataricum（L.） Gaertn）审定品种为材料,从91对苦荞EST-SSR引物中筛选出50对多态性引物。综合考虑引物多态性信息量（PIC）大小、鉴别力（DP）,筛选出等位变异位点数在2~4,PIC值在0.60~0.78之间的6对引物（SSR9007、SSR6873、SSR7642、SSR2234、SSR6789、SSR68216）构建了供试品种的分子指纹图谱。遗传多样性聚类分析结果表明,供试品种的相似系数为0.50~0.99。当遗传相似系数为0.60时,可将供试品种分为4大类群,其中54.3%的供试品种被聚为一类,表明苦荞审定品种遗传组成差异较小,遗传基础狭窄。聚类结果表明各类群间没有明显的地域分布趋势,但能较好的反映供试品种间的亲缘关系。     

甘蔗属不同种及优良甘蔗栽培品种的SSR标记遗传多样性分析

应用21对SSR引物与毛细管电泳技术,分析了52个甘蔗属品种的遗传多样性。共检测出327个SSR标记,平均每对引物检测15.6个。选择141个共显性标记构建SSR标记指纹图谱数据库,利用DNAMAN软件与UPGMA统计方法分析参试材料遗传多样性。DNAMAN软件同源分析显示,新台糖16号与台优1号之间的同源性最高(87%),品种之间最小的同源性为55%;利用UPGMA统计方法可把参试材料分成4个遗传相似性较高的类群。结果表明,SSR标记与毛细管技术的结合,可构建甘蔗种质资源SSR标记指纹图谱、分析甘蔗种质资源遗传多样性。聚类分析显示参试甘蔗材料的遗传基础相近,为了提高甘蔗选育种效率,应拓宽甘蔗选育种亲本的遗传基础,提高杂交栽培品种的抗虫、抗病等特性。     

43个福建省茶树品种指纹图谱构建及遗传多样性分析

为了解福建省茶树品种的遗传多样性,从38对SSR引物中筛选出扩增条带清晰,多态性较好的引物23对,对43个茶树品种的遗传多样性进行了分析,并选取扩增条带少、多态性较高的7对SSR引物构建茶树品种指纹图谱。聚类结果表明,43个茶树品种可聚成10个类群,遗传距离最远的品种是‘八仙茶’,距离最近的品种是‘福鼎大毫茶’与‘九龙大白茶’;福建省选育的乌龙茶品种比绿茶品种的遗传多样性丰富;同时来源于共同亲本的品种表现出较高的相似系数,聚为一类;来源地相同的品种也因有较高的相似系数而聚为一类;地理距离越远的品种,遗传距离也越大。这为茶叶生产选种和茶树遗传改良提供参考依据。     

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