睡菜离体快繁技术的研究

以睡菜的幼嫩茎段为外植体,接种到附加不同浓度激素配比(6-BA/NAA)的MS培养基,诱导睡菜愈伤组织、芽及根的生长。研究发现,外植体在1.0mg/L 6-BA+0.1mg/L NAA+MS的培养基上培养10d,可观察到浅绿色的愈伤组织。愈伤组织转接到4.0mg/L 6-BA+0.3mg/L NAA+MS培养基上2周左右可生成芽。对带芽的愈伤组织再进行诱导生根进而形成完整再生植株,最适根诱导培养基为0.3mg/L 6-BA+1.0mg/L NAA+MS培养基。该实验采用植物离体快繁技术成功建立了睡菜再生体系,为睡菜种苗规模化奠定了技术基础。     

康乃馨茎段愈伤组织诱导及植株再生(简报)

以康乃馨无菌苗茎段为外植体,在MS 6-BA 0.5mg/L NAA0.2mg/L培养基上诱导产生愈伤组织,愈伤组织在MS 6-BA 0.5mg/L NAA 0.2mg/L培养基上诱导芽效果较好,芽苗在1/2MS NAA 0.1mg/L培养基上可诱导生根。     

叶子花的组织培养与微繁技术研究

叶子花茎尖、茎段接种在MS附加不同浓度组合的6-BA、IAA、IBA、NAA培养基上可诱导茎尖及腋芽的生长而获得无性系芽,无性系芽茎尖和茎段在MS附加6-BA0．5mg／L,NAA0．05mg／L进行继代培养,一般不形成丛生芽,以茎尖生长和腋芽萌生增殖,增殖系数为2．73;高度大于3cm的增殖芽在1／2 MS附加IAA lmg／L、IBA lmg／L、NAA0．2mg／L培养基上生根率为80．5％,生根苗用“二步法”移栽成活率在97％以上。无性系芽的幼叶、茎段在MS附加6-BA和NAA、2,4-D培养基上能高频产生愈伤组织,但愈伤组织在所试验的所有培养基上均无不定芽或胚状体的分化。     

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.     

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。     

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。     

皱皮木瓜愈伤组织诱导与快速繁殖

以皱皮木瓜（Chaenomeles speciosa）当年生枝条的茎尖和茎段为外植体进行离体培养与快速繁殖。结果表明：芽萌发及愈伤组织诱导的最佳培养基是MS＋2.0mg·L^-1 6-BA＋1.0mg·L^-1NAA;愈伤组织分化最佳培养基是MS＋1.0mg·L^-1 6-BA＋0.05mg·L^-1NAA;芽增殖最佳培养基是MS＋1.0mg·L^-1 6-BA＋0.05-0.1mg·L^-1NAA,其增殖系数为6.59;最佳生根培养基是1/2MS＋1.0mg·L^-1IAA,生根率为86.7%;采用珍珠岩二步移栽,成活率可达90%以上。     

皂质芦荟的组织培养

将皂质芦荟的茎段及幼苗作为外植体进行组织培养,试验结果表明：皂质芦荟的茎段经40d左右可诱导形成愈伤组织,再经20d萌生再生芽：幼苗培养需要30d左右基部直接分化再生芽。同时经试验筛选出愈伤组织形成、再生芽分化和生根的最适培养基为：MS＋6－BA 2.0mg/L NAA 0.1mg/L、MS 6-BA 3.0mg/L NAA 0.1mg/L和MS NAA 0.3mg/L。     

紫色大花矮牵牛组织培养与植株再生

矮牵牛叶片外植体在MS+6-BA 1.0mg/L+NAA 0.1mg/L培养基上培养3周后产生致密的浅绿色愈伤组织;转入芽分化培养基MS+6-BA 0.5mg/L+4-PU 0.5mg/L+NAA 0.1mg/L 1周后,从愈伤组织表面不断分化产生幼芽;待幼芽长至3cm时转接至生根培养基1/2MS+NAA 1.0 mg/L+GA₃0.5mg/L中生根,长成完整植株。     

皱皮木瓜愈伤组织诱导与快速繁殖

以皱皮木瓜(Chaenomeles speciosa)当年生枝条的茎尖和茎段为外植体进行离体培养与快速繁殖。结果表明: 芽萌发及愈伤组织诱导的最佳培养基是MS+2.0 mg.L^-1 6-BA+1.0 mg.L-¹ NAA; 愈伤组织分化最佳培养基是MS+1.0 mg.L^-1 6-BA+0.05 mg.L^-1 NAA; 芽增殖最佳培养基是MS+1.0 mg.L^-1 6-BA+0.05-0.1 mg.L^-1 NAA, 其增殖系数为6.59; 最佳生根培养基是1/2MS+1.0 mg.L^-1 IAA, 生根率为86.7%; 采用珍珠岩二步移栽, 成活率可达90%以上。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细