二花蝴蝶草的组织培养及植株再生

二花蝴蝶草(Torenia biniflora)为玄参科蝴蝶草属一年生植物,分布于广东、广西等亚热带地区,是一种观赏性较高的野生花卉。在自然生长条件下,二花蝴蝶草繁殖速度慢、增殖率低,而且花色和花型种类偏少,无法满足市场多样化的要求。植物组织培养技术为观赏植物的品种改良和新品种选育提供了新途径,目前蓝猪耳、蔓性蝴蝶草和单色蝴蝶草等蝴蝶草属植物的组织培养已获得成功,但二花蝴蝶草的组织培养尚未见有相关报道。该研究以二花蝴蝶草全展叶片为外植体,研究了培养基中添加不同种类和浓度植物生长物质对不定芽诱导和生长的影响,以及离子强度和不同浓度IBA对生根的影响。根据不定芽的诱导率和平均芽数筛选出最佳不定芽诱导培养基,并从生根率、平均根数和平均根长等方面筛选出最佳生根培养基。结果表明:不定芽诱导与植物生长物质的浓度和种类有关,以MS+6-BA 0.5 mg·L-1+NAA 0.2 mg·L-1培养基的诱导效果最佳;二花蝴蝶草生根的最佳基本培养基为1/2MS,不同浓度的IBA对二花蝴蝶草的生根影响也不相同,其中以IBA(0.05 mg·L-1)诱导不定芽的生根效果最佳。该研究建立了二花蝴蝶草的高频离体再生体系,为二花蝴蝶草的快速繁殖和遗传转化研究奠定了基础。     

肠道菌群参与心血管疾病发病过程

肠道菌群参与代谢综合征的现象已有报道,而在2011年4月的Nature上又报道了肠道菌群参与心血管疾病的发生。这接二连三的发现不得不让我们重新审视一下这位生活在我们肠道中,且一直被认为对人体有重要保护作用的朋友。作者在筛选血浆心血管疾病标记物过程中,发现有三个候选物质呈明显相关,似乎处于同一代谢通路。经确认分别是胆碱、TMAO和betaine,这三种物质不仅同在食物来源磷脂酰胆碱代谢通路上,且其代谢必须依赖肠道菌群参与。肠道中胆碱在肠道微生物作用下生成TMA并被人体吸收,TMA在肝脏被FMO3氧化生成TMAO,发挥其作用。在研究中发现血浆胆碱、     

微繁殖改良植物

促进生根 Horticultural Research AFRC研究所的T.R.Marks指出,从微繁殖的Rhododendron yakushimanum小植株分离出的微插条具有高的生根能力,这一能力在移出培养基6周内保留于取自小植株的小插条中。此外,经2年的离体培养后,与成熟嫁接植株的插条相比,微繁殖植株插条的生根率及根发育的数量均较大。这些比率近似于从较早的微插条小插条中获得的数据。可是,从常规的和微繁殖母株分离的叶状插条的生根需要植物生长素,而由离体培养的微插条生根不需要植物生长素。Marks把生根率高的现象归因干插条的“返老还童”。在另一项研究中,Marks发现Rhododendron插条的生根潜力如何与栽培品种的选择关系重大。在离     

直杆桉试管短枝人工包埋种皮的研究

桉树是速生经济用材树种,其材质好,广泛应用于工、农业,可作为能源(称石油树)、造纸及人造纤维的重要原料。有关桉树组织培养,国际上早在1965年就开展了研究,1969年从愈伤组织诱导出了小植株,到目前为止,已从许多种类的不同外植体诱导出了不定芽或体细胞胚胎发生,并相继在许多实验室开展快速繁殖研究,而且成功地摸索出一套建立无性繁殖的方法。但桉树的试管苗生根仍是一大难关。de Fossard(1974)曾报道未能诱导出根。后来,一些研究者虽报道诱导出根,但生根率很低。为此,我们用人工膜包埋技术试验并结合调整外源激素种类和浓度,使生根率大大提高。结果报道如下。     

唐菖蒲球茎中抗真菌物质的部分性质研究

本文报道唐菖蒲球茎中抗真菌活性物质的成分及其分子量测定方法和结果。用沸水提取,经过超滤、透析、柱层析,纯化到一种有抗真菌活性的物质。排除了它是蛋白质、核酸、脂类及小分子物质的可能性,确定这是一种多糖,定名为唐菖蒲抗真菌多糖（Gladiolus hntifungal Polysaccharide,简称GAFS）。真空旋转蒸发干燥后,用苯酚-硫酸法测得干燥后的样品糖含量为44．08％,用FPLC（快速蛋白质液相层析仪）测其分子量为15750。     

一种利用基因表达变化检测、鉴别抗生素的新方法

本研究利用基因表达变化构建一个高通量检测筛选抗生素化合物的新方法。采用含luxCDABE报道子的质粒pCS26和pMS402为载体,构建大肠杆菌重组质粒、筛选铜绿假单胞菌以及沙门氏菌的随机启动子库,获得对抗生素有反应的启动子-报道子融合体,构成抗生素筛选体系。通过重复实验筛选出15个启动子-报道子融合体,它们对不同抗生素有不同的反应,通过这一系统可以检测样品中的抗生素,并初步判断与现有抗生素的异同。使用这种方法可以进行高通量筛选潜在的抗菌物质。     

多基因型黑果枸杞高效快繁体系的建立

旨为建立适用于不同种源多基因型的黑果枸杞高效稳定的组培再生体系,为工厂化育苗与大面积推广奠定基础。收集7个不同种源地的黑果枸杞种子并制备无菌苗,利用植物组织培养技术,研究不同种类、不同浓度植物生长调节剂对黑果枸杞生根和分化的影响。在黑果枸杞的茎段诱导分化培养基筛选过程中,针对黑果枸杞培养过程中容易出现的玻璃化现象,通过多种培养基比较,确定了一种最适合不同种源多基因型黑果枸杞茎段分化的培养基MS+蔗糖30 g/L+琼脂7 g/L+6-BA 0.1 mg/L;在黑果枸杞的叶片诱导分化培养基筛选过程中,通过调节生长素类物质及细胞分裂素的浓度,获得一种适合于不同基因型的黑果枸杞叶片分化的培养基MS+蔗糖30 g/L+琼脂6 g/L+NAA 0.5 mg/L+6-BA 0.5 mg/L;在黑果枸杞生根培养基的筛选过程中,通过改变生长素浓度,获得了一种最适合于不同种源多基因型黑果枸杞生根的培养基1/2MS+蔗糖30 g/L+琼脂7.5 g/L+IBA0.25 mg/L。在大规模试验的基础上,克服了不同种源黑果枸杞使用一种培养基时在生根分化过程中常出现的玻璃化、不生根、不发芽等问题,建立了适宜不同种源多基因型黑果枸杞高效稳定的组织培养再生体系。     

紫茉莉不定芽诱导和植株再生

紫茉莉(Mirabilis jalapa)观赏价值较高,是一种重要的污染修复植物.组织培养技术为植物品种改良和选育的重要途径,但紫茉莉离体快繁方面的研究尚未见有相关报道.该研究以紫茉莉叶片和茎段为外植体,通过观察和统计外植体愈伤组织和不定芽的诱导情况,分析不同植物生长物质对紫茉莉植株再生的影响.结果表明:紫茉莉带芽茎段比较适合丛生芽的诱导,当带芽茎段在MS+1.0 mg·L-16-BA+1.5 mg·L-1 KT+1.0 mg·L-1 NAA+0.05 mg·L-1 TDZ培养基中培养时,不定芽的增殖系数较高.无论是MS或1/2MS培养基,都可诱导不定根的产生,其中生根效果较好的培养基为1/2 MS+0.5 mg·L-1 NAA.该研究结果探索了紫茉莉组织培养的最适条件,根据愈伤组织诱导率和不定芽的增殖系数筛选出了适宜不定芽诱导的培养基类型,根据不定芽生根情况确定了最佳的生根诱导培养基,为建立紫茉莉高效稳定的再生和遗传转化体系奠定了基础.     

P物质放射免疫测定法及在大白鼠动情周期中垂体内P物质含量的变化

本文报道了P物质放射免疫测定方法的建立。用此方法测定了大白鼠脑不同部位(下丘脑、垂体、嗅球和小脑)中P物质的含量,还测定了大白鼠不同情期垂体中P物质含量的变化,观察到间情期垂体P物质的含量最高,动情前期显著降低,动情期仍维持在低水平。因此认为P物质在垂体水平对LH和FSH的分泌有抑制性影响。     

草莓中黄酮类物质的测定以及与抗氧化活性之间的相互关系

报道草莓中黄酮类物质含量的测定方法,并比较了总抗氧化成分与抗氧化活性(DPPH,FRAP)之间的相互关系.黄酮类物质的水解随着HCl浓度和水解时间的不同发生较大的差异,结果表明,总多酚类物质和总黄酮类物质之间有很高的相关关系,总多酚类物质和总黄酮类物质对DPPH有很高的相关关系,而且总多酚类物质和总黄酮类物质对FRAP的相关关系各为r=0.958, P ＜0.05和r=0.936, P ＜0.05,从结果可以推测:草莓体现出很强的抗氧化活性,这与草莓中的总多酚类物质成分密不可分.     

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