植物生长调节剂对白头翁叶片培养的影响

以白头翁试管苗叶片为外植体,以MS为基础培养基,探讨不同细胞分裂素和生长素对叶片不定芽诱导、愈伤组织的诱导、增殖、再分化的影响。实验结果表明：细胞分裂素TDZ适合于白头翁叶片培养,与生长素搭配使用使叶片发生分化;2,4-D对愈伤组织的诱导能力相对较强。叶片直接诱导不定芽的激素组合为TDZ0．3mg／L＋NAA0．1mg／L;愈伤组织增殖的激素组合为TDZ0．2mg／L＋2,4-D0．2mg／L,将愈伤组织转接到TDZ和NAA组合的培养基上时会再分化。     

费尔干猪毛菜愈伤组织的诱导、分化及植株再生体系的建立

探讨了植物生长调节剂、外植体等因子对费尔干猪毛菜（Salsola fergartica Drob．）愈伤组织诱导、分化与植株再生的影响。结果表明：2,4-D与6-BA组合使用时,在一定浓度范围内均有愈伤组织产生,最佳的诱导培养基为MS＋2,4-D2．0mg／L＋6-BA0．2mg／L,下胚轴为诱导愈伤组织的最佳材料;愈伤组织继代培养较好的培养基为MS＋NAA0．1mg／L＋6-BA1．0mg／L;愈伤组织不定芽分化培养基为MS＋6-BA0．5mg／L＋NAA0．05mg／L;根分化的培养基为1／2MS＋IBA0．2mg／L,且生根率可达72％。以带柄子叶为外植体,诱导丛生芽的最佳分化培养基为MS＋6-BA1．0mg／L,再生频率可达90．74％。     

黄山药愈伤组织诱导与分化

采用黄山药野生植株作为外植体,试验了不同激素处理对黄山药愈伤组织的诱导、分化影响,结果表明：不同的外植体的诱导率差别较大,叶片的诱导率最高,最高达到85．7％,茎段的诱导率较低,平均诱导率仅10％左右。以叶片作为外植体诱导愈伤组织的最佳培养基配方为MS 2,4-D2．0mg／L 6-BA2．5mg／L;愈伤组织分化生芽的最佳配方为MS BA1．0mg／L NAA0．5mg／L 蔗糖2％ pH6．4;愈伤组织分化生根的最佳配方诱MS BA1．0mg／L NAA0．1mg／L 蔗糖3％ pH6．80。     

雌雄栝楼的组织培养研究

对雌雄栝楼（Trlctmsanthes kirilowii Maxim）分别进行组织培养的研究结果表明：在雌雄栝楼组织培养过程中,愈伤组织的诱导和分化适宜的培养基均存在性别差异。愈伤组织诱导的适宜培养基分别是,雌性栝楼培养基为MS＋NAA0．5mg／L＋IBA0．5mg／L＋6-BA1．5mg／L;雄性栝楼培养基为MS＋NAA0．1mg/L＋IBA0．5mg／L＋6-BA0．5mg／L和MS＋NAA0．1mg／L＋IBA1．0mg／L＋6-BA1．0mg/L。愈伤组织分化的适宜培养基分别是,雌性栝楼培养基为MS＋NAA0．1mg／L＋IBA0．4mg／L＋6-BA1．2mg／L;雄性栝楼培养基为MS＋NAA0．3ms／L＋IBA0．2mg／L＋6-BA0．8mg／L;雌雄栝楼无根苗生根的适宜培养基均为MS＋NAA0．1mg／L。     

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％。     

尾巨桉胚培养与快速繁殖研究(简报)

尾巨桉种胚在改良H＋2,4-D0．5mg／L＋6-BA0．1mg／L＋蔗糖3％培养基上诱导形成愈伤组织,每个愈伤组织块在改良H＋6-BA1．0mg／L＋NAA0．5mg／L＋蔗糖5％培养基上分化形成芽点,经30d继代培养,产生有效苗30～50株。利用改良MS＋6-BA0．4mg／L＋NAA0．2mg／L＋蔗糖3％培养基进行壮苗,改良MS＋ABT0．6mg／L＋IBA0．2mg,L＋蔗糖1．5％培养基进行生根诱导．有效成苗率达95％以上。移栽成活率达98％．     

肯氏相思的组织培养(简报)

1．植物名称肯氏相思（Acaciacunninghamia）2．材料类别茎尖、嫩茎段和叶片3．培养条件基本培养基为MS。（1）诱导愈伤组织培养基为：MS＋6－BA1．0＋NAA0．2,（2）诱导分化培养基为：MS＋6－BA0．5＋NAA0.2,（3）诱导生极培养基为：3／4MS＋NAA0．2,以上激素浓度均为mg／L     

火龙果愈伤组织诱导与植株再生

为了建立火龙果愈伤组织诱导与植株再生体系,以火龙果茎段、幼苗和子叶为外植体进行离体培养试验。结果表明：茎段诱导愈伤组织的最优培养基为1／2MS＋2,4-D2．0mg·L^-1＋6-BAO．5mg·L^-1,诱导子叶愈伤组织的最适培养基是1／2MS＋2,4-D2．0mg·L^-1＋6-BA1．0mg·L^-1,诱导愈伤组织分化的最优培养基为1／2MS＋6-BA4．0mg·L^-1＋NAA0．5mg·L^-1,最佳生根培养基为1／2MS＋6．BA1mg·L^-1＋NAA0-3mg·L^-1。     

牡丹子叶离体再生体系研究

以日本牡丹品种“太阳”为试验材料,研究不同激素组合对牡丹胚初代培养、愈伤组织诱导、分化及植株再生的影响。结果表明：牡丹胚初代培养在1．0mg／L6-BA＋0．25mg／LTDZ的MS培养基上,牡丹胚诱导率最高可达96．1％;剪取无菌子叶转接到附加含有2．0mg／L6-BA＋2．0mg／L2,4-D＋0．2mg／LTDZ的MS培基养上进行愈伤组织培养．诱导率可达100％;愈伤组织在MS＋0．5mg／LKT培养基上分化出芽,分化率达26．6％：不定芽在1／2MS＋1．0mg／LNAA＋4．0mg／LIBA生根培养基上的生根率达27％．     

桃儿七成熟胚的离体培养研究

以MS为基本培养基,通过添加不同激素和附加物等措施对桃儿七种子成熟胚进行了无菌苗和愈伤组织诱导初步研究。研究结果表明：0．5mg／L IAA＋0．2mg／L KT＋0．3mg／L GA3处理可获得生长良好的无菌苗,诱导率达41．67％。1．0mg／L 2,4-D＋0．4mg／L KT＋0．3mg／L GA3处理愈伤组织诱导率可达36．67％,添加500mg／L水解酪蛋白（CH）或10mg／L D-生物素有益于愈伤组织的诱导。光照和变温培养有利于提高无菌苗和愈伤组织的诱导率,有效降低褐化率。     

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.     

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.     

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