宽叶弹簧草的组织培养与快速繁殖

以宽叶弹簧草Ornithogalum concodianum休眠期的鳞茎为材料,进行离体再生体系研究。结果表明,培养基MS(KH2PO4 加倍)+6-BA 4.0 mg·L-1+NAA 0.5 mg·L-1适宜鳞茎诱导,诱导率达54.2%;对鳞茎增殖的主要影响因素为6-BA,培养基2/3MS(KH2PO4 加倍)+6-BA 4.0 mg·L-1+NAA 1.0 mg·L-1+蔗糖2%适宜鳞茎增殖,增殖系数为4.0;培养基1/2MS(大量元素减半,其他成分不变)+IBA 1.0 mg·L-1+NAA 1.0 mg·L-1+活性炭1.0 g·L-1生根效果较好;适宜的栽培基质为草炭∶园土∶火山岩(体积比)＝5∶1∶1,成活率可达89.6%。     

宜昌百合小鳞茎诱导的初步研究

以宜昌百合当年成熟的鳞片为外植体,接种于21种不同激素配比的MS培养基上诱导小鳞茎,找出最适培养基。实验结果表明:在小鳞茎诱导过程中,最佳诱导培养基为:MS+6-BA1.5mg·L-1+2,4-D1mg·L-1。生根培养基以MS+IBA0.5mg·L-1为好。     

蝴蝶兰的组织培养和快速繁殖

通过诱导残败花梗上的休眠芽萌发,以萌发的幼叶和去茎尖的茎段为外植体进行组织培养,建立了蝴蝶兰(Phalaenopsis amabilis Bl.)的无菌繁殖体系,并筛选出最佳培养基组成.诱导休眠芽萌发的最佳培养基为不加任何激素的MS0培养基;原球茎诱导的适宜培养基为MS 3.0 mg·L-1 6-BA 0.5 mg·L-1 ZT 30 mg·L-1柠檬酸和MS 5.0 mg·L-1 6-BA 30 mg·L-1柠檬酸 30%椰乳(CM),其中茎段的诱导效果明显优于叶片,诱导率达95%;诱导无菌苗生根的最适培养基为1/4 MS 1.0 mg·L-1 6-BA 0.1 mg·L-1 NAA,生根率可达79%.     

血叶兰的组织培养与快速繁殖

以血叶兰的嫩茎段为外植体, 建立了血叶兰的组培快繁体系。结果表明： 芽诱导最适宜的培养基是MS＋6-BA 5.0 mg·L-1; 最适芽增殖培养基为MS＋6-BA 5.0 mg·L-1＋NAA 0.5 mg·L-1＋TDZ 0.3 mg·L-1, 芽增殖率达4.92倍; 最佳壮苗培养基为MS＋NAA 0.3 mg·L-1＋GA3 1.0 mg·L-1＋15%椰汁, 芽苗高度达到4.33 cm, 芽粗为0.61 cm; 生根最适培养基为1/2MS＋IBA 1.0 mg·L-1＋15%香蕉＋0.5 g·L-1活性炭, 生根率在93.0%以上; 炼苗后, 移栽在泥炭土＋珍珠岩＋松树皮（3：1：1, V/V/V）混合基质中, 存活率高于87.0%。     

紫花亚菊（Ajania purpurea）的组织培养与快速繁殖

以紫花亚菊茎段为外植体对其进行组织培养,MS为基本培养基,设置不同激素浓度配比,对试验结果进行观察分析,筛选出适合的配方：启动培养基为MS＋6-BA0.5mg·L-1＋NAA0.01mg·L-1;继代培养基MS＋6-BA0.3mg·L-1＋NAA0.05mg·L-1,组培苗分化率高;不定根最适诱导培养基为：1/2MS＋IBA0.15mg·L-1,生根率达90%以上,组培苗移栽成活率达95%。     

影响茎用芥菜愈伤组织诱导和植株再生的因素

茎用芥菜子叶培养在MS 0.25 mg·L-1NAA 0.5 mg·L-16-BA 0.25 mg·L-12,4-D培养基上,可获得较高质量的愈伤组织.愈伤组织培养在MS 1～1 mg·L-16-BA 0.2 mg·L-1NAA培养基上分化频率为8.3%,而在加有羧苄青霉素和头孢霉素的培养基上,最高分化频率可达52.4%.将获得的再生植株转移到1/2MS 0.1 mg·L-1 NAA的生根培养基中,可获得完整植株.     

盐节木同化枝的腋芽丛生与快速繁殖

本文通过同化枝腋芽丛生方式建立了盐生植物盐节木的快速繁殖体系。以在MS附加200 mmol·L-1 Na Cl的培养基上无菌种子萌发、生长共计4~5个月、高约3~4 cm的盐节木小苗为材料,从上截取0.5 cm长的同化枝小段为外植体,培养在MS附加不同浓度的6-BA与NAA的培养基中。结果表明:同化枝腋芽诱导与增殖最佳培养基均为MS+0.05 mg·L-1 6-BA+1mg·L-1 NAA或MS+1 mg·L-1 6-BA,初代培养30 d后,腋芽诱导率达97.5%,平均芽增殖系数为2.50;继代增殖培养时,将同化枝切成1 cm长的小段芽增殖系数提高到4.92;一次性芽苗伸长与生根培养基为MS+0.05 mg·L-1 IBA,生根率达99%;小苗经炼苗后移栽到沙子、营养土和蛭石体积比为1:1:1的基质中,成活率可达91%。     

枇杷叶荚蒾的愈伤组织诱导及植株再生

以枇杷叶荚蒾幼叶为外植体,MS为基本培养基,研究不同种类和浓度的植物生长调节物质对愈伤组织诱导、分化及生根的影响,建立了枇杷叶荚蒾再生体系。结果表明:枇杷叶荚蒾最佳灭菌组合为75%酒精预处理20s,再用0.1%HgC12浸泡12min;最佳愈伤组织诱导培养基为MS+6-BA1.0mg·L-1+NAA0.25mg·L-1+2,4-D1.0mg·L-1,诱导率最高达92%;最适芽分化培养基为MS+6-BA1.5mg·L-1+NAA0.2mg·L-1,分化率达87.25%;适宜的生根培养基为1/2MS+NAA1.0mg·L-1,生根率达85%。     

水杉愈伤组织诱导及植株再生

通过愈伤组织诱导器官发生途径,建立了水杉（Metasequoia glyptostroboides）的植株再生体系,探讨了不同外植体（种胚、幼叶切块、茎段、根段）和植物生长调节剂对不定芽直接再生和愈伤组织诱导器官发生的影响。结果表明：以种胚、无菌苗叶片、茎段和根作为外植体,在MS补加2,4-D、NAA和6-BA不同组合的培养基上都能诱导得到愈伤组织,其中种胚诱导愈伤组织效果最好,诱导率可达100%,茎诱导效果次之,诱导率为97.1%。诱导愈伤组织效果较好的培养基有：MS＋1.0mg·L-12,4-D＋0.5mg·L-16-BA、MS＋0.1mg·L-16-BA＋1.0mg·L-1NAA、MS＋0.5mg·L-16-BA＋1.0mg·L-1NAA、MS＋1.0mg·L-16-BA＋1.0mg·L-1NAA、MS＋0.5mg·L-16-BA＋2.0mg·L-1NAA、MS＋1.0mg·L-16-BA＋2.0mg·L-1NAA和MS＋0.5mg·L-12,4-D＋0.5mg·L-1NAA。以愈伤组织在MS培养基上植株再生效果最好,再生率为62.5%。     

油桐叶柄高效直接再生体系的建立

以油桐无菌苗叶柄为外植体,研究植物生长调节剂对其离体培养及植株再生的影响。结果表明:叶柄直接诱导不定芽的最佳培养基1/2MS+3.0 mg·L-1 6-BA+0.05 mg·L-1 IAA,诱导率达91.67%;最佳继代增殖培养基1/2MS+3.0 mg·L-16-BA+0.05 mg·L-1 IBA+1.0 mg·L-1 GA3,增殖系数可达4.89;最佳生根培养基为1/2MS+0.05 mg·L-1 IBA,生根率96.18%。炼苗移栽到泥炭土:珍珠岩:黄土=2:1:1的基质中,成活率达93.55%以上。     

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