球子蕨孢子的无菌繁殖

以球子蕨成熟孢子为外植体,研究了不同激素及浓度对其孢子萌发、愈伤组织诱导、丛生芽分化及生根的影响。结果表明:孢子萌发最适培养基为1/2MS+2%蔗糖,20d后萌发率达55.7%;诱导愈伤组织的最适培养基为MS+0.5mg·L-1KT+0.5mg·L-12,4-D,诱导率达36%,愈伤组织为绿色颗粒状;颗粒状愈伤组织在不添加激素的MS培养基中即可生长出大量丛生芽,转化率可达49.3%;低浓度(0.2mg·L-1)的IAA可有效促进幼孢子体苗生根。     

矮晚柚的组织培养与快速繁殖

以矮晚柚种子萌发的无菌苗为实验材料,利用茎尖和上胚轴诱导丛生芽的发生,利用丛生芽获得再生植株。实验表明:矮晚柚成熟和未成熟种子在1/2MS、MS上均能萌发,萌发率最高可达96%,成熟种子萌发的无菌苗更利于后期的分化。最适外植体为无菌苗的上胚轴,筛选出丛生芽最佳增殖培养方案为MS+6-BA 2.0 mg·L~(-1)+NAA 0.1 mg·L~(-1)+蔗糖40 g·L~(-1)+靠近茎尖上胚轴,最高增殖系数达8.4,最佳生根培养基为1/2MS+NAA 0.2 mg·L~(-1)+IBA 0.2 mg·L~(-1)+活性炭0.2 g·L~(-1),生根率达90%以上。移栽至蛭石+珍珠岩+营养土(1:1:2)的营养砵上,成活率可达80%。     

白及种子萌发与快速繁殖技术的研究

将不同胚龄的白及种子接种到不同培养基中进行培养,对白及种子萌发率、萌发时间、丛生芽增殖、生根等方面进行了研究。结果表明:白及种子萌发率与其胚龄及有胚率成正相关,萌发时间则与胚龄及有胚率成负相关;胚龄16周的种子在1 g/L花宝1号 2 g/L花宝2号的培养基上萌发率可达84%;胚龄等于或大于20周的种子萌发率不受培养基成分的影响,均可达100%,萌发时间只需7 d;丛生芽增殖的最佳培养基为1/2 MS 4.0 mg/L6-BA 0.2 mg/L NAA 100 g/L CM,其增殖倍数达4.41倍;诱导生根较好的培养基为1/2 MS 0.2 mg/L NAA,生根率达90%。     

紫花三叉白芨快繁技术研究

为建立白芨(Bletilla striata)高效实用的组织培养快繁体系,以紫花三叉白芨成熟未开裂的蒴果、块茎、叶片为外植体,筛选最佳外植体材料,并研究不同生长调节剂浓度培养基对原球茎萌发、丛生芽诱导以及生根影响。结果表明,白芨种子为最佳外植体材料;培养基KC + NAA 0.5 mg·L–1有利于白芨原球茎丛生芽诱导;培养基MS + 6-BA 2.0 mg·L–1 + NAA 0.2 mg·L–1 + 10%椰汁有利于丛生芽增殖及成苗;将2 cm高幼苗转入生根培养基1/2MS + NAA 0.5 mg?L–1中,其生根效果最好,生根率达98.67%。     

金钱草的试管快速繁殖研究

以中药金钱草 (LysimachiachristinaeHance)的茎段为外植体于MS附加不同激素配比的培养基上 ,探讨丛生芽诱导及生根培养的条件。在MS +6 -BA 0 .5～ 1.5mg·L-1+IBA 0 .2～ 0 .5mg·L-1和MS +6 -BA 1.5mg·L-1+NAA 0 .5mg·L-1的培养基上均可获得良好的丛生芽诱导 ,苗的生长迅速 ,繁殖系数高 ;在MS或MS +IBA 0 .1mg·L-1培养基上易于诱导生根。丛生芽诱导率和生根率均为 10 0 %。     

新疆鼠尾草的组织培养与植株再生

1 植物名称新疆鼠尾草(Salvia deserta Schang). 2 材料类别种子萌发形成的幼嫩叶片. 3 培养条件基本培养基为MS.(1)丛生芽诱导及增殖培养基:MS 6-BA 2.0 mg·L-1(单位下同) NAA0.25;(2)生根培养基:1/2MS IBA 0.5.培养基(1)的蔗糖浓度为3.0%,(2)的蔗糖浓度为1.5%;琼脂为7.0 g·L-1,pH 6.0.     

阔鳞鳞毛蕨孢子的无菌繁殖

以阔鳞鳞毛蕨（Dryopteris championii）成熟孢子为外植体,研究了不同植物生长调节剂及浓度对其孢子萌发、愈伤组织诱导、丛生芽分化及生根的影响。结果表明：1/2MS＋2%蔗糖为孢子萌发最适培养基,20 d后萌发率达65%;诱导愈伤组织的最适培养基为MS＋KT 0.5 mg.L-1＋2,4-D 1 mg.L-1,诱导率达39.8%,愈伤组织为绿色颗粒状;颗粒状愈伤组织在MS＋KT0.2 mg.L-1的培养基中生长出大量丛生芽,转化率可达66.3%;MS＋IAA 0.2 mg.L-1＋NAA 0.2 mg.L-1培养基可有效促进幼孢子体苗生根。     

印度沉香的组织培养和快速繁殖

1植物名称印度沉香(Aquilaria agallocha). 2材料类别种子长成的无菌苗的顶芽. 3培养条件 (1)种子萌发培养基:1/2MS;(2)丛生芽诱导培养基:MS 6-BA 0.1 mg·L-1(单位下同);(3)芽伸长培养基:MS 6-BA 0.05;(4)生根培养基:1/2MS.上述培养基均附加3%蔗糖、0.8%琼脂,pH 5.8.培养温度为(26±1)℃,光照12h·d-1,光照度2 000 lx.     

柳杉种子无菌苗组培快繁体系的建立

以柳杉种子在无菌条件下萌发的幼苗为外植体,研究3种基本培养基和3种植物生长调节剂对不定芽诱导、增殖及生根的影响,建立了完整的组培快繁体系。结果表明,柳杉种子经预处理后,用75%酒精消毒20 s,再用0.1%HgCl2浸泡600 s的消毒效果较好,污染率为10.00%,成活率为82.33%;丛生芽诱导的最适培养基配方为DCR＋6-BA 0.2 mg·L-1,诱导率较高,达66.67%;丛生芽增殖的最适培养基配方为DCR＋6-BA 0.2 mg·L-1＋IBA 0.05 mg·L-1,增殖倍数达到11.00;适宜的生根培养基为DCR＋NAA 0.01 mg·L-1＋IBA 0.2 mg·L-1,生根率为90.00%,平均生根数为4.09。     

葡萄柚种子无菌苗组培快繁体系的建立

以葡萄柚种子在无菌条件下萌发的幼苗作为外植体供体,子叶切断作为丛生芽初代诱导培养的接种材料,以MT作为基本培养基,通过调节不同植物生长调节剂及其浓度组合、不同质量浓度的蔗糖,选择最佳初代培养基、继代培养基和生根培养基,对葡萄柚组培快繁技术体系进行研究。结果表明:(1)葡萄柚种子经预处理后,先用75%酒精表面灭菌15 s,再用0.1%Hg Cl2浸泡20 min的消毒效果最好,污染率为18.33%,萌发率为89.91%;(2)初代培养的最适培养基为MT+1.0 mg·L-16-BA(6-苄氨基腺嘌呤)+0.2 mg·L-1IBA(吲哚丁酸)+0.2 mg·L-1GA(赤霉素)+蔗糖40 g·L-1,腋芽诱导率较高,为93.33%;(3)浓度为0.2 mg·L-1的GA能提高初代培养的腋芽诱导率,但还达不到显著水平;(4)继代培养的最适培养基为MT+0.5 mg·L-16-BA+0.2 mg·L-1IBA+0.2 mg·L-1GA+蔗糖40 g·L-1,丛生芽增殖系数达到4.25,芽深绿色,茎粗壮,节间较长,生长旺盛;(5)浓度为0.2 mg·L-1的GA能显著提高继代培养的增殖系数;(6)最适合继代培养的蔗糖浓度为40 g·L-1,丛生芽长势极好;(7)最佳生根培养基为1/2 MT+NAA 0.2 mg/L+蔗糖40 g·L-1+AC 0.1%,生根率达68.89%,根粗壮;(8)生根苗移栽30 d后成活率在75%以上。该研究建立了葡萄柚的组织培养快繁技术体系,为葡萄柚的规模化生产提供了可行的技术依据。     

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.