籼粳交稻米蒸煮品质性状的遗传效应分析

以2个粳型光温敏核不育系和4个籼稻品种为材料,配制籼粳交组合,用包括基因型×环境互作效应的胚乳性状遗传模型对3个蒸煮品质性状(直链淀粉含量、胶稠度、碱消值)进行了遗传研究,结果表明:直接加性和母体加性效应对三个性状的遗传变异起主要作用.基因型×环境互作主要表现为显性×环境以及细胞质×环境互作.直链淀粉含量的普通遗传率都不显著,只有较高的互作母体遗传率;胶稠度具有显著的普通直接遗传率和互作细胞质遗传率;碱消值的普通直接遗传率和普通母体遗传率都极显著.根据遗传效应预测值对供试亲本的利用价值作了评价。     

不同环境条件下粳型杂交稻米碾磨品质性状的遗传效应分析

采用包括基因型×环境互作效应的种子遗传模型,对粳型杂交稻稻米碾磨品质性状进行了遗传研究.结果表明:各碾磨品质性状除了受制于种子直接效应、细胞质效应和母体效应等遗传主效应外,还明显受到各基因型×环境互作效应的影响.其中糙米率性状以遗传主效应为主,而精米率、整精米率性状以基因型×环境互作效应为主.在遗传主效应中,糙米率性状主要受种子直接加性效应、母体加性效应的控制;在基因型×环境互作效应中,精米率和整精米率性状都是以种子直接加性×环境互作效应和母体加性×环境互作效应为主,细胞质×环境互作效应也起着较为重要的作用.大部分稻米碾磨品质性状的狭义遗传率均较高,其中糙米率性状以普通狭义遗传率为主,而精米率和整精米率性状则以互作狭义遗传率为主.另外,根据性状的遗传效应预测值对各亲本的育种利用价值作了评价.     

籼粳杂交稻穗部性状的遗传效应及其与环境互作

采用包括基因型与环境互作效应的加性显性加性×加性上位性遗传模型,分析了不同环境下籼粳杂交稻穗部性状的遗传特点.结果表明,除了主穗粒数的加性与环境互作和二次枝梗数的显性与环境互作不显著外,其他性状均存在显著和极显著的加性、显性、加性×加性上位性遗传效应及其与环境的互作效应,其中均以显性效应为主,显性与环境互作效应对枝梗性状的影响较为明显.遗传率分析表明,各性状的普通广义遗传率最大,互作遗传率也有一定作用.杂种优势预测表明,除了一次、二次枝梗数外,其他性状均表现正向的杂种优势,基因型与环境互作只影响杂种优势表达的程度,而不改变其方向.遗传效应预测值结果表明,IR6615837、IR6560085、明恢63和R6694个亲本可以明显改良杂交后代多数穗部性状,且环境影响程度较小,可作为优良亲本列于育种计划中.     

小麦冠层叶片性状基因效应的岭估计

选用6套具有P_1、P_2、B_1、B_2、F_1和F_2的六世代遗传材料,采用K．Mather提出的六参数遗传模型,用岭回归方法估算了小麦冠层叶片性状的基因效应．结果表明：各冠层叶片性状都存在1～3种上位性效应,遗传机制较为复杂,其遗传模式可分为加性—显性—上位性、以加性为主的加性—显性—上位性和显性—上位性3种,还讨论了现有几种常用遗传模式的复共线性,以及对冠层叶片性状的选择．     

陆地棉数量性状的遗传分析 Ⅰ.17个农艺性状的基因效应估计

由11组各含P_1、P_2、F_1、F_2、B_1和B_2家系的平均数及其方差,估计了陆地棉有关株型的10个性状和有关产量、品质的7个性状的基因效应。结果表明,株高,主茎节间长,第5、10、15果枝节间长和纤维长度的遗传,除有加性、显性效应外,尚有不可忽略的上位性效应;第1、10果枝与主茎夹角的遗传属加性-显性模型;第1果枝节间长,第5、15果枝与主茎夹角,每株铃数,单铃籽棉重,衣分,霜前籽棉、籽棉和皮棉产量则主要是加性遗传效应。因而一般地说,株型性状的遗传并不比产量性状简单。     

棉花优异纤维品质性状的双列杂交分析

利用5个具有不同纤维品质性状的品种(系)配制完全双列杂交组合20个,通过亲本和F1的2年随机区组试验,结果为除纤维整齐度受环境等因素影响较大,其余性状主要受遗传因素控制;在与环境的互作中,纤维强度和长度的互作效应小,麦克隆值的加性和母体效应及伸长率的显性效应与环境的互作较大,均达到了显著水平;遗传主效中,所有的研究性状不存在母体效应,以加性为主;强度与长度加性遗传率高,分别占77．6％和73．2％;麦克隆值的加性效应占45．2％,显性效应所占的比例在纤维性状中最高,为11．5％。纤维品质性状的群体平均优势仅麦克隆值的较高(3．2％),达到了显著水平,其余性状的优势仅为-0．4％-0．7％。纤维品质性状的遗传结果与杂种优势一致。在杂种优势利用时,可以通过双亲平均值的高低来预测F1的纤维品质表现。纤维强度、长度和细度的加性遗传率高,这些性状均可以早代选择。     

水稻单株有效穗数主基因＋多基因混合遗传分析

选择单株有效穗数差异大的3个亲本CB1（15.3）、CB4（6.4）和CB7（11.8）,配制CB1×CB4和CB7×CB4组合,建立了相应的P_1、F_1、P_2、B_1、B_2、F_2群体,将其分为中、晚两个生产季节种植,考察了有效穗数性状.利用主基因＋多基因混合遗传模型理论的Akaike信息准则（AIC）在B_1、B_2、F_2代中鉴定影响数量性状的主基因存在与否,主基因存在时通过分离分析估计主基因和微效基因的遗传效应及所占总变异的分量.结果表明该性状在所有B_1、B_2、F_2中均符合2对加性-显性-上位性主基因＋加性-显性-上位性多基因的遗传模式,主基因遗传率为30.64%-72.26%,多基因遗传率为3.41%-28.20%,总基因遗传率为45.96%-87.29%;相同组合种植季别主基因遗传率及一阶参数对比表明,杂交亲本的选择及种植季别对该性状遗传率影响较小,h_a、h_b、j_（ab）、j_（ba）值均为负值表明显性效应和加性显性互作对该性状表达具有抑制作用.     

玉米单株穗数及其它数量性状的基因效应与遗传变异分析

对于玉米单株穗数、籽粒产量及其他重要数量性状进行了世代平均值分析。试验包括多穗×非多穗自交系间的28个杂交组合的P_1、P_2、F_1、F_2、B_1和B_2群体两年的结果。单株穗数、开花前日数和穗位高在大多数组合内表现为显著的加性基因效应。籽粒产量、开花前日数、株高和穗位高几乎在所有组合内都表现显著的显性效应。所研究的10个性状平均加性效应引起的变异比例一般都超过显性效应变异比例。三种基因效应中,上位效应对世代平均值遗传变异的贡献最小,而且往往不显著。籽粒产量的遗传变异主要由基因的显性效应所引起。     

籼粳杂交稻穗部性状的遗传效应及其与环境互作

采用包括基因型与环境互作效应的加性-显性-加性×加性上位性遗传模型,分析了不同环境下籼粳杂交稻穗部性状的遗传特点.结果表明,除了主穗粒数的加性与环境互作和二次枝梗数的显性与环境互作不显著外,其他性状均存在显著和极显著的加性、显性、加性×加性上位性遗传效应及其与环境的互作效应,其中均以显性效应为主,显性与环境互作效应对枝梗性状的影响较为明显.遗传率分析表明,各性状的普通广义遗传率最大,互作遗传率也有一定作用.杂种优势预测表明,除了一次、二次枝梗数外,其他性状均表现正向的杂种优势,基因型与环境互作只影响杂种优势表达的程度,而不改变其方向.遗传效应预测值结果表明,IR66158-37、IR65600-85、明恢63和R6694个亲本可以明显改良杂交后代多数穗部性状,且环境影响程度较小,可作为优良亲本列于育种计划中.     

甘蓝型油菜主要农艺性状的遗传模型和基因效应分析

本文以甘蓝型优质油菜(81008×Tower)正反交各12个世代的资料,按照4种不同的遗传模型,对包括单株产量在内的8个农艺性状的遗传方式进行了详尽地分析。结果表明:所有性状的遗传皆不符合简单的加性-显性模型,上位性效应普遍存在,且对世代平均数有较大影响;单株产量及几个产量性状的遗传均受重复型互作基因的控制,杂种优势需利用三基因或多基因间的互作效应。     

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