大果良种沙棘愈伤组织诱导及植株再生的研究

大果良种沙棘的幼嫩茎尖,茎段外植体接种在MS,1／2MS附加不同浓度配比的IAA,IBA,BA,NAA培养基上可诱导茎尖及腋芽生长,将诱导产生的无性系芽接种在MS或1／2MS附加BA0．3－0．5mg/L,NAA0．05mg/L的培养基上可形成丛生芽,同时在小叶片和嫩茎上诱导产生愈伤组织,继续培养愈伤组织表面形成大量的绿色突起,进一步分化成不定芽,在相同培养基上,不定芽上可直接产生不定芽,从而形成多达数百个的不定芽族,不定芽长至3cm时切下转至1／2MS附加IAA或IBA 0．2mg/L的培养基上可生根而形成完整 的再生植株。     

人参果的脱毒和快速繁殖

用人参果无菌实生苗茎尖进行组织培养,经过5代高温加剥离茎尖培养的方法,可以完全脱除病毒。无菌小苗茎尖接种在MS 6-BA1．0mg／L NAA0．1mg／L 2．4-D0．10mg／L的培养基上能够产生淡黄色愈伤组织,继续培养分化出较多芽点;把带芽点的愈伤组织转移至MS 6-BA1．0mg／L IAA0．05mg／L的培养上可分化出丛生芽且继代增殖效果较好;丛生芽在1／2MS NAA0．1mg／L PP3330．2mg／L的培养基上易生根,可以获得健壮完整的小苗。     

海巴戟(Morinda citrifolia L.)组织培养研究

以海巴戟（Morinda citrifolia L．）种子为试材,在不剥除种皮的情况下,在MS无激素培养基上播种1年内未见发芽,在剥除种皮的情况下,在MS无激素培养基上发芽率最高,50d内可达75％。海巴戟子叶和下胚轴均能单独由细胞分裂素BA0．7～2．0mg／L诱导不定芽发生,不定芽可直接从外植体发生,也可从愈伤组织发生,添加生长素NAA0．05～0．1mg／L则完全抑制不定芽发生,同时强烈促进愈伤组织生长和不定根发生。带芽茎段在BA1．5mg／L配合低浓度生长素时均能通过腋芽萌发和不定芽发生而增殖。芽梢在NAA0．1mg／L、IBA0．1mg／L或IAA0．1mg／L均有根群发生,但NAA0．1mg／L诱导生根时切口愈伤组织较多,部分不定根由愈伤组织发生。而IAA0．1mg／L诱导生根时根群欠发达,以IBA0．1mg／L最佳。     

迷迭香的离体培养(摘编)

培养条件 　　(1)愈伤组织诱导培养基:MS＋6-BA 1.0 mg*L－1(单位下同)＋IAA 0.025＋NAA 0.1;(2)增殖培养基：MS 6-BA 0.5;(3)分化培养基:MS 6-BA 3.0＋IAA 1.0;(4)茎尖直接诱导丛生芽培养基: MS 6-BA 0.8 IAA 0.2;(5)伸长培养基:MS 6-BA 1.0＋IAA 0.2;(6)生根培养基:MS IBA 0.25. 　　……     

不同生长调节剂对狗肝菜愈伤组织诱导和离体快繁的影响

目的 :研究不同生长调节剂对狗肝菜愈伤组织诱导和离体快繁的影响。方法 :狗肝菜不同外植体在附加不同生长调节剂的培养基上诱导愈伤组织 ,比较愈伤组织的诱导率 ;用 3因子 5水平的正交实验 ,比较不同生长调节剂对丛生芽诱导的影响 ;在附加不同生长调节剂的培养基上比较芽增殖倍数 ;附加不同浓度NAA的培养基上比较生根效果。结果 :愈伤组织诱导率相对以叶片最高 ,茎段次之 ,最后为叶柄 ;愈伤组织诱导的最佳培养基为MS 6-BA0 .5 NAA1 .5 ;不同激素对茎段芽诱导的影响次序为 6-BA>KT >NAA ,芽诱导的最佳培养基为MS 6-BA2mg/L KT1mg/L NAA0 .5mg/L ;芽继代增殖的最佳激素组合是MS 6-BA2mg/L NAA2mg/L ,增殖倍数达 3.0 0 ,影响芽继代增殖的因素次序为 6-BA >NAANAA0 .5mg/L的生根效果较好。结论 :附加一定的生长调节剂能提高狗肝菜愈伤组织的诱导率和离体快繁的效率。     

剑叶龙血树组织培养与快速繁殖的研究

用剑叶龙血树的腋芽、顶芽或茎段作外植体,构建了剑叶龙血树组织培养再生体系。试验结果如下:剑叶龙血树腋芽、顶芽或茎段诱导愈伤组织的最佳培养基为MS+6-BA 2.0mg/L+NAA 0.5mg/L,诱导率达95%;选择MS+6-BA 2.0mg/L+NAA0.2mg/L+30g/L的蔗糖+8g/L琼脂培养基有利于芽的分化和增殖,在1/2MS+NAA 0.2mg/L+IBA0.4mg/L+活性炭的培养基中诱导生根效果最好。     

玉竹的组织培养与快速繁殖

以玉竹[Polygonatum odoratum (Mill.) Druce]根状茎、叶片和茎段为外植体,于附加不同激素配比的MS培养基中诱导愈伤组织、不定芽和不定根,探讨增殖培养和植株再生的条件.结果表明,叶片和茎段外植体诱导愈伤组织和芽的分化率很低;而根状茎外植体易于培养,有较高的诱导率和增殖倍数,其愈伤组织、不定芽和不定根的诱导率分别可达87%、90%和99%以上.适宜根状茎外植体愈伤组织诱导的培养基为MS+1.0 mg/L 6-BA+0.5 mg/L NAA,有利于增殖和丛生芽分化的培养基为MS+2.0 mg/L 6-BA+0.5 mg/L IBA和MS+3.0 mg/L 6-BA+0.1 mg/L NAA,而1/2MS+3.0～5.0 mg/L NAA适宜诱导试管苗生根培养.试管苗的移栽成活率可达85%以上.     

西藏红景天组织培养研究

以西藏红景天嫩叶和幼茎为材料,研究西藏红景天不同外植体的离体培养技术。结果表明：西藏红景天嫩叶是诱导愈伤组织和芽的理想外植体,诱导松散型愈伤组织有两种培养基,分别是黑暗培养下MS 6-BA2．0 mg／L NAA0．2mg／L和MS 6-BA3．0mg／L NAA0．3mg／L;生芽培养基为MS 6-BA2．0mg／L IAA0．25mg／L;生根培养基为MS IAA0/5～1．0mg／L。     

杜衡离体繁殖的研究

以马兜铃科植物杜衡为研究材料,试图通过茎尖培养来获得愈伤组织,继而诱导愈伤组织分化形成杜衡小植株。试验证明：杜衡茎尖在MS基本培养基附加6-BA 0.6mg/l和NAA0.1mg/;这一激素组合上可诱导茎尖基部形成愈伤组织;将愈伤组织分割转接到附加6-BA0.2mg/l和NAA0.01mg/l 的MS基本幅度基上可使愈伤组织分化形成小芽;分化形成的芽置于1/8-1/4MS(大量元素减少,其余成分不变)附加6-BA0.1mg/l和GA1mg/l的培养基上,可促使芽的正常生长;新生芽转接在1/4MS附加IBA0.5mg/l培养基上促使其生根。     

香蕉草叶柄离体培养与快速繁殖(简报)

以香蕉草叶柄为外植体进行离体培养及快速繁殖条件研究。结果表明,叶柄外植体在培养基MS＋6-BA 2．0mg／L＋NAA 0．3mg／L＋蔗糖30g／L＋卡拉胶7g／L上诱导形成愈伤组织后,转入分化培养基MS＋KT 1．0mg/L＋NAA0．2mg/L可诱导不定芽分化;不定芽转入增殖培养基MS＋6-BA 1.0mg/L＋NAA 0．5mg／L可旺盛增殖,增殖系数4．5。不定根分化培养基为MS＋IBA 0．2mg／L＋NAA 0．05mg／L,生根苗在水族箱移栽成活率达98％。     

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     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.