烟草白粉病抗性基因的遗传分析

以烟草抗白粉病品种台烟7号为母本,感病品种NC89为父本,构建6个世代的群体,利用主基因 多基因混合遗传模型的分离分析方法,研究烟草白粉病的抗性遗传规律。结果表明,烟草白粉病抗性的遗传是由两对加性-显性-上位性主基因 加性-显性-上位性多基因（E-0模型）控制的。B1、B2和F2世代主基因的遗传率分别为88.05%、32.62%、84.43%,主基因遗传率很大,说明可以在抗病育种早期进行选择;B1、F2世代多基因遗传率均为0.00%,说明烟草白粉病的发生受一定环境影响。     

烤烟叶数、叶面积的遗传分析

以叶数较少、叶面积较小的烤烟品种丸叶为母本(P1),以叶数较多、叶面积较大的烤烟品种Coker319为父本,构建了6个世代分离群体,利用植物数量性状主基因+多基因混合遗传模型的联合分离分析方法,分析烤烟杂交组合丸叶×Co-ker319叶数、叶面积的遗传效应。结果表明:烤烟的叶数和叶面积均受2对加性-显性-上位性主基因+加性-显性-上位性多基因(E0)控制,其中叶数遗传以加性效应及显性×显性上位性效应为主,叶面积几种遗传效应差不多,其上位性效应>加性效应>显性效应,叶数和叶面积在B1世代的主基因遗传率分别为36.91%和2.13%,多基因遗传率分别为31.00%和19.53%,B2世代的主基因遗传率分别为51.60%和50.92%,多基因遗传率分别为16.84%和13.26%,F2世代的主基因遗传率分别为42.63%和30.32%,多基因遗传率分别为42.08%和12.18%,叶数和叶面积的主基因遗传率较高,适合在早代选择。     

大白菜抽薹性状的主基因＋多基因遗传分析

以大白菜易抽薹自交系06S1703和耐抽薹自交系06J32形成的P1、P2、F1、F2、B1和B2等6个世代为材料,应用主基因+多基因多世代联合分析方法,对大白菜抽薹性状进行了研究.结果表明,大白菜的抽薹性受2对加性-显性-上位性主基因+加性-显性-上位性多基因控制,其中2对主基因的加性效应值分别为-3.575 8和-13.619,显性效应值分别为-3.755 2和-2.257 7.B1、B2和F2世代的主基因遗传率分别为87.95%、95.13%和96.25%,只在B1群体中检测到多基因效应,遗传率仅为1.39%,说明大白菜的抽薹性是以主基因遗传为主,可以进行早期选择.     

陕北黄芥芥酸含量的主基因+多基因遗传分析

以吴旗黄芥×长安芥菜组合的6个世代P1、P2、F1、B1、B2和F2群体为材料,利用植物数量性状主基因+多基因模型的多世代联合分析方法研究了该组合芥酸含量的遗传特征.结果表明:吴旗黄芥×长安芥菜组合芥酸含量受2对加性-显性-上位性主基因+加性-显性-上位性多基因(E模型)控制.主基因效应中,加性效应大于显性效应,第一对主基因加性效应(da)和显性效应(ha)分别为-4.718 0和4.419 5;第二对主基因的加性效应(db)和显性效应(hb)分别-4.005 8和2.023 7;2对主基因对芥酸含量的贡献差异较大,第二对主基因加性和显性效应之和占第一对主基因加性和显性效应之和的65.98%;2对主基因间存在一定的互作效应(绝对值在0.338 7～3.694 1),其中第一对主基因显性×第二对主基因加性效应(jba)较大,为3.694 1.B1、B2和F2群体芥酸含量主基因遗传率分别为68.83%、44.76%和87.99%;多基因遗传率分别为20.29%、41.21%和0,F2代表现出较高的遗传力,可在早期世代对芥酸含量进行选择.     

白菜叶裂数性状主基因+多基因遗传分析

以叶片全缘的大白菜自交系(P1)和叶缘深裂的欧洲白菜型油菜自交系(P2)杂交所获得的6个基本世代(P1、P2、F1、B1、B2、F2)为材料,应用主基因+多基因混合遗传模型对白菜叶裂数进行遗传分析。结果表明,白菜的叶裂数受2对加性-显性-上位性主基因+加性-显性多基因的控制,第1对主基因加性效应为-1.154 7,显性效应为-1.516 8;第2对主基因的加性效应为-1.154 8,显性效应为1.034 9;多基因加性效应为0.591 9,显性效应为1.145 2,2对主基因间存在明显的交互作用。B1、B2和F2世代叶裂数的主基因遗传率分别为88.48%、90.40%、93.03%;多基因遗传率分别为4.114%、0、0。B1、B2、F2世代叶裂数表现出较高的主基因遗传率,受环境影响较小。在白菜叶裂数性状的改良中应以主基因为主,并适于早代选择。     

黄瓜抗黑星病不同基因源的遗传分析

基于苗期人工接种鉴定结果,获得2份抗黑星病黄瓜材料(HX1,Cucumis sativus var.sativus,DI=5;HX5,C.sativusvar.xishuangbannesis,DI=38.7)和1份感病材料(HX8,C.sativus var.sativus,DI=80)。利用上述3份材料构建了2个组合(HX1×HX8,HX5×HX8)的6世代群体(P1、P2、F1、F2、B1和B2),并分别进行黑星病苗期人工接种鉴定。采用主基因+多基因联合遗传分析方法进行遗传分析,结果表明2份材料抗黑星病的遗传规律不同。组合HX1×HX8的F1单株表现为抗病,而组合HX5×HX8的F1单株基本表现为感病。HX1对黑星病的抗性符合两对加性-显性-上位性主基因+加性-显性多基因混合遗传模型(E_1模型),HX5的抗性遗传符合加性-显性多基因模型(C模型)。在组合HX1×HX8中,两对主基因的加性效应均大于显性效应,B1、B2和F2群体的主基因遗传率分别为72.51%、98.19%和96.91%,多基因遗传率均为0,表明HX1对黑星病的抗性以主基因遗传为主;HX5对黑星病的抗性遗传以多基因的显性效应为主。     

萝卜不同抗源对黑腐病抗性的遗传分析

不同抗病基因的挖掘是作物持久抗性遗传改良的基础。本研究利用2份抗黑腐病(Xanthamonas campestris pv.campestris)萝卜(Raphanus sativus L.)材料(KB10Q-22、KB10Q-24)和1份感病材料(KB10Q-33)构建了2个F2群体,采用苗期剪叶+喷雾法接种黑腐病菌Xcc8004进行抗病性鉴定。应用P1、P2、F1、F24个世代的数量性状主基因+多基因混合遗传分析方法,研究了萝卜2个不同抗源抗黑腐病的遗传规律,结果表明2份材料的遗传规律不同。以KB10Q-22为母本的F1植株表现为抗病,其遗传模型为E_0模型,即2对加性-显性-上位性主基因+加性-显性-上位性多基因模型;而以KB10Q-24为母本的F1植株表现为感病,其遗传模型为D_0模型,即1对加性-显性主基因+加性-显性-上位性多基因模型。两群体主基因遗传率分别为87.73%和55.64%,抗性遗传以主基因为主。     

辣椒果实性状主基因+多基因遗传分析

以果实性状差异较大的一年生辣椒材料C.annuum B9431(P1)和灌木辣椒材料C.frutescens H108(P2)为亲本,构建4世代群体(P1、P2、F1、F2),应用数量性状主基因+多基因混合遗传模型方法对辣椒6个果实性状进行遗传分析,为辣椒果实性状QTL定位及分子标记辅助育种研究奠定理论基础。结果表明:6个果实性状均符合2对主基因+多基因遗传模型。其中,单果重量、果实纵径、果实横径、果形指数和果肉厚度5个性状均符合E-0模型,即2对加性-显性-上位性主基因+加性-显性-上位性多基因混合遗传模型;果柄长度最佳遗传模型为E-5,即2对完全显性主基因+加性-显性多基因模型。单果重量、果实纵径、果实横径、果形指数、果肉厚度和果柄长度主基因遗传率分别为87.64%、37.67%、82.46%、94.82%、83.33%和40.00%,多基因遗传率分别为7.50%、54.56%、10.53%、0.27%、12.96%和37.78%。     

烤烟不同生育时期产量性状的遗传效应分析

以烤烟高产品种竖把老母鸡和台烟7号与低产品种TI245配制成2个杂交组合,分别获得6个世代植株(P1、P2、F1、F2、B1、B2),运用主基因+多基因混合遗传多世代联合法对2个组合不同生育时期的产量性状进行遗传分析。研究结果表明,2个组合的产量性状在性状建成中发挥调控作用的基因数目与基因效应存在发育阶段性差异。基因加性效应与显性效应存在于整个发育过程中,且效应程度在不同生育时期存在明显差异,同时加性×加性、显性×显性互作效应在产量性状的发育过程中呈间断性表达。基因遗传力在不同生育时期存在差异,现蕾期产量性状的表型变异受基因遗传效应的决定作用高于其他2个生育时期,受环境因素影响小,且不同组合间的基因效应也存在显著差异,组合Ⅱ的遗传效应明显高于组合Ⅰ。不同组合的烤烟产量性状在不同生育时期主基因+多基因遗传效应差异显著,受环境影响程度不同,因此在育种工作中既要考虑基因效应,又要注意环境影响。     

辣椒开花期的主基因+多基因遗传分析

应用植物数量性状主基因+多基困混合遗传模型对早熟辣椒‘E100’与‘L101’杂交组合多个世代群体开花期进行了联合分析.结果表明:开花期由两对加性-显性-上位性主基因+加性-显性-上位性多基因的控制;主基因遗传率在B1、B2和F2世代分别为55.27%、53.83%和76.05%;B1、B2和F2世代多基因遗传率分别为34.13%、42.78%和16.94%.     

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     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV