植物生长物质对大花红景天愈伤组织诱导及苗再生的影响

以大花红景天植物的茎、叶、芽、种子为材料,采用DPS软件正交设计法,通过添加不同植物生长物质,考察其对大花红景天愈伤组织形成及苗再生的影响,为低海拔条件下建立大花红景天植株再生体系提供数据基础。结果表明：种子和芽是诱导愈伤组织最适宜的外植体;植物生长物质对愈伤组织形成的影响大小为6-BA〉KT〉2,4-D〉NAA〉IAA,愈伤组织形成的最佳培养基为MS＋6-BA 4.0 mg.L-1＋KT 0.1 mg.L-1＋NAA 0.1 mg.L-1＋IAA 0.2 mg.L-1;不定芽分化的最佳培养基为MS＋TDZ 0.5 mg.L-1＋NAA 0.5 mg.L-1,诱导率达63.14%,不定芽数平均为11.4。本试验获得的最佳培养基配方,适宜在低海拔条件下进行快速诱导大花红景天的愈伤组织和植株再生。     

北玄参毛状根诱导及其植株再生

利用发根农杆菌A4和R1601感染北玄参(Scrophularia buergeriana)叶片外植体,诱导产生毛状根,产生的毛状根可在无激素的液体和固体MS培养基上快速生长。rol B基因的PCR检测表明,Ri质粒中的T-DNA片段整合到了北玄参毛状根的基因组中。毛状根在附加0.5 mg·L–1 6-BA及0.1 mg·L–1 NAA的MS固体培养基上形成绿色愈伤组织,之后形成不定芽,并获得再生植株;毛状根在附加0.5 mg·L–1 6-BA及0.02 mg·L–1 NAA的MS固体培养基上培养约15–20天可直接形成不定芽,且不定芽的诱导率达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%。     

芨芨草愈伤组织器官发生及植株再生

芨芨草(Achnatherum splendens(Trin.)Nevski)种子消毒并在MS培养基上萌发获得无菌苗,以幼苗的叶鞘和胚轴为外植体诱导愈伤组织,经继代后进一步诱导不定芽及生根.研究结果表明,诱导愈伤组织最适合的培养基为B5 1.5 mg·L-12,4-D 0.5 mg·L-1NAA;诱导芽分化较适合的培养基为B5 0.5 mg·L-1 6-BA 0.2 mg·L-1 NAA;1/4B5 1.0 mg·L-1NAA 0.2 mg·L-1 IBA 1.0 g·L-1活性炭培养基则有利于芨芨草试管苗的生根.本实验建立了完整的芨芨草植株再生体系,移栽成活率高.     

芨芨草愈伤组织器官发生及植株再生

芨芨草(Achnatherum splendens (Trin.) Nevski)种子消毒并在MS培养基上萌发获得无菌苗, 以幼苗的叶鞘和胚轴为外植体诱导愈伤组织, 经继代后进一步诱导不定芽及生根。研究结果表明, 诱导愈伤组织最适合的培养基为B5+1.5 mg.L-12,4-D+0.5 mg.L-1 NAA; 诱导芽分化较适合的培养基为B5+0.5 mg.L-1 6-BA +0.2 mg.L-1 NAA; 1/4 B5+1.0 mg.L-1 NAA+0.2 mg.L-1 IBA +1.0 g.L-1活性炭培养基则有利于芨芨草试管苗的生根。本实验建立了完整的芨芨草植株再生体系, 移栽成活率高。     

香石竹毛状根诱导、离体培养及其植株再生

为了探讨利用发根农杆菌遗传转化所产生的毛状根来创新香石竹种质的可能性,本文采用叶盘法,建立了发根农杆菌Agrobacterium rhizogenes对香石竹Dianthus caryophyllus L.叶片外植体的遗传转化及其植株再生体系。结果表明,发根农杆菌ATCC15834感染香石竹幼嫩叶片外植体12 d后,从叶片外植体切口中脉处产生白色毛状根,21 d后约90%的叶片外植体产生毛状根。所获得的无菌毛状根能在无外源激素的MS固体和液体培养基中快速自主生长。PCR扩增和硅胶薄层层析结果显示发根农杆菌Ri质粒的rol B和rol C基因以及冠瘿碱合成酶基因已在香石竹毛状根基因组中整合并得到表达。将毛状根置于MS+6-BA 1.0-3.0 mg/L+NAA 0.1-0.2 mg/L中培养15 d后产生淡黄绿色的疏松愈伤组织。愈伤组织不定芽分化的最适培养基为MS+6-BA 2.0 mg/L+NAA 0.02 mg/L,培养6周后不定芽分化率为100%;平均每个愈伤组织产生30-40个不定芽;将不定芽转至1/2 MS或1/2 MS+0.5 mg/L NAA的培养基中10 d后产生不定根,发育成再生植株。再生植株移植于栽培基质中20 d后,成活率达95%以上。     

药用植物金荞麦愈伤组织诱导与植株再生

目前转基因技术已成为植物定向遗传改良的重要手段,而建立稳定高频的离体再生系统是实现遗传转化的基础和前提.本试验以25 ～30 d苗龄的金养麦(Fagopyrum dibotrys)无菌苗叶片、茎节间、叶柄为外植体进行愈伤组织诱导与植株再生研究.结果表明:叶片在MS +2,4-D 4.0 mg/L +6-BA 1.0 mg/L培养基上愈伤组织诱导率达到89％.茎节间在MS +2,4-D 2.0 mg/L +6-BA 2.0 mg/L培养基上愈伤组织诱导率为87％.叶柄在MS +2,4-D 4.0 mg/L +6-BA 2.0 mg/L+ IBA 0.2 mg/L培养基上的最高诱导率仅为54％.愈伤组织分化不定芽的适宜培养基为MS +6- BA2.0 mg/L +TDZ0.2 mg/L +NAA0.2 mg/L;金荞麦不定芽在1/2 MS +NAA 0.5 mg/L的培养基上生根效果最好.组培再生植株经炼苗后移栽到田间成活率达80％以上,且生长表现正常.高频完整再生体系的建立,为金荞麦进一步遗传操作和扩大药材资源奠定了基础.     

金线莲外植体筛选及愈伤组织诱导研究

以金线莲茎段、叶片、茎片、不定芽为试材,分别在添加6-BA、ZT、NAA、KT 5个不同处理的MS及1/2MS培养基上培养,诱导愈伤组织。结果表明,以茎段、茎片、不定芽为外植体,在MS + 6-BA 2.0 mg/L + NAA0.5 mg/L、MS + NAA 2.0 mg/L + KT 0.1 mg/L和MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + ZT 0.2 mg/L培养基中培养,均能成功诱导愈伤组织。不定芽为诱导愈伤组织最佳外植体,最佳培养基为MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + KT 0.2 mg/L。     

费约果外植体灭菌及愈伤组织的诱导

以费约果(Feijoa sallowiana Berg.)嫩叶和带芽茎段作为外植体,研究费约果愈伤组织诱导的最佳条件和方法.结果表明:(1)最佳基本培养基是MS;(2)二步灭菌法优于一步灭菌法;(3)嫩叶和带芽茎段愈伤组织诱导的最佳活性炭浓度分别为2.0 g L-1和3.0 g L-1;(4)最佳青霉素浓度分别为200 mg L-1和50 mg L-1;(5)光培养方式优于暗培养方式.(6)费约果嫩叶诱导愈伤组织的最佳培养基是MS 2.0 mgL-1 2,4-D 1.0 mg L-1 KT(或0.1 mg L-1NAA);(7)带芽茎段的最佳培养基是MS 1.0 mg L-16-BA 0.5 mg L-1NAA 1.0 mg L-1GA或MS 2.0 mg L-16-BA 0.1 mgL-1NAA 1.0 mgL-1GA.     

蓝花楹组织培养与快速繁殖研究

以蓝花楹(Jacaranda mimosifolia Humb.et Bonpl.)胚轴为外植体进行组织培养和快繁体系建立的研究。结果表明,蓝花楹种子经40℃-45℃温水浸泡后发芽率较高,达到55.7%。蓝花楹不定芽和愈伤组织诱导的最适培养基分别为MS+6-BA2.0 mg L-1+NAA 0.1 mg L-1+2,4-D 0.1 mg L-1和M S+6-BA 0.5 mg L-1+NAA 1.0 mg L-1+2,4-D 1.0 mg L-1。不定芽和愈伤组织增殖的最适培养基分别为改良MS培养基+6-BA 0.5 mg L-1+NAA 0.5 mg L-1+IBA 0.5 mg L-1和MS+6-BA 1.0 mg L-1+NAA 0.5 mg L-1+ZT 3.0 mg L-1。愈伤组织分化最适培养基为M S+BA 1.0 mg L-1+NAA 0.5 mg L-1+2,4-D 0.5 mg L-1。最适生根培养基为1/2MS+蔗糖20 g L-1+NAA 0.1 mg L-1+活性炭2.0 g L-1,生根率达78.3%。     

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