海滨锦葵胚轴愈伤组织诱导及植株再生

以海滨锦葵(Kosteletzkya virginica)胚轴为外植体, 在9种不同激素配比的培养基上进行愈伤组织诱导、继代培养、不定芽分化及生根培养, 确定了植株再生的最适培养条件: (1)愈伤组织诱导最适培养基为MS + IAA 1.0 mg.L-1 + KT 0.3 mg.L-1 + sucrose 30 g.L-1 + agar 8 g.L-1, 愈伤组织诱导率为93.94%; (2)不定芽诱导最适培养基为MS + IAA 0.1 mg.L-1 + ZT 0.5 mg.L-1 + sucrose 30 g.L-1 + agar 8 g.L-1, 不定芽诱导率为65.83%; (3)生根最适培养基为MS + sucrose 30 g.L-1 +agar 8 g.L-1, 生根率为96.67%。炼苗移栽后, 成活率可达85%。     

蒙花忍冬的组织培养与快速繁殖研究

以金银花 蒙花 品系的茎段为外植体 ,于 MS和 B5附加不同激素配比的培养基上 ,探讨愈伤组织形成和丛生芽诱导及生根培养的条件 .诱导愈伤组织和丛生芽的培养基为 B5+BA2 .0 m g· L- 1 +KT0 .2～ 0 .5 mg· L- 1+IAA 0 .5～ 1 .0 mg· L- 1 +L H 1 0 0 0 m g· L- 1 ,继代增殖培养的培养基为 B5+BA 2 .0 m g· L- 1 +KT 0 .5 m g·L- 1 +IAA1 .0 m g· L- 1 +L H1 0 0 0 m g· L- 1和 B5+BA2 .0 mg· L- 1 +KT0 .36 m g· L- 1 +IAA1 .0 mg· L- 1+CH 1 0 0 0 m g· L- 1 +1 / 2 MS :大量元素 ,生根培养基为 1 / 2 MS +IBA 0 .2 mg· L- 1 +L H 1 0 0 0 mg·L- 1 .结果表明 L H和 CH在金银花愈伤组织和丛生芽诱导方面具明显的作用     

万寿菊杂交亲本的离体培养

以万寿菊‘钻石’雄性不育株的幼嫩叶片和子房为外植体进行离体快繁,结果表明:培养基MS+0.8 mg·L-1 IAA+0.6 mg·L-1 6-BA+30 g·L-1蔗糖既有利于叶片愈伤组织的诱导也有利于不定芽的分化,愈伤组织诱导率达97.9％,不定芽诱导率达45.8％;培养基MS+0.5 mg·L12,4-D+0.5 mg·L-16-BA+ 30 g·L-1蔗糖为诱导子房愈伤组织的最佳培养基,出愈率为77.8％;培养基MS+0.05 mg·L -1 NAA+0.5 mg·L-1 6-BA+ 30g·L-1蔗糖为诱导子房愈伤组织不定芽分化的最佳培养基;将不定芽接至MS培养基上,7d后即可生出不定根,生根率可达98％,移栽成活率达90％以上.     

利用丛生芽和愈伤组织微繁技术培养紫茎泽兰的研究

通过丛生芽直接增殖和愈伤组织再分化两条途径建立紫茎泽兰的无性系,可为进一步研究紫茎泽兰入侵的分子生态机制提供植物材料。结果表明:MS+BA2.0mg·L-1+NAA0.05mg·L-1为丛生芽增殖的最适培养基,MS+BA0.1mg·L-1+NAA0.1mg·L-1和MS+BA2.0mg·L-1+NAA0.2mg·L-1分别适于叶片愈伤组织的诱导和分化,而1/2MS+IAA0.1mg·L-1对生根最有利。     

马铃薯叶片高效再生体系的建立

以4个马铃薯栽培品种为试材,进行了叶片离体再生研究,结果表明:东农303、鄂1号叶片愈伤组织诱导的最佳培养基为MS+6-BA2.5mg·L-1+NAA0.2mg·L-1;费乌瑞它为MS+6-BA2.0mg·L-1+NAA0.1mg·L-1;夏波帝为MS+6-BA2.0mg·L-1+NAA0.2mg·L-1,愈伤组织的诱导率均可达100%.诱导不定芽分化的最佳培养基分别是:费乌瑞它、鄂1号为MS+6-BA2.5mg·L-1+GA35.0mg·L-1;东农303为MS+6-BA1.0mg·L-1+IAA0.1mg·L-1+GA32.5mg·L-1;夏波帝为MS+6-BA2.5mg·L-1+IAA0.5mg·L-1+GA32.5mg·L-1,其不定芽分化率分别达94.3%、100%、100%和90%.     

秦岭野百合鳞片植株再生体系的建立

以鳞片为外植体,建立了秦岭野百合(LiliumbrowniiF.E.Brown)植株再生体系。结果表明愈伤组织诱导的最适培养基为MS+6-BA1.0mg·L-1+NAA0.1mg·L-1,最适继代培养基为MS+6-BA0.5mg·L-1+NAA0.1mg·L-1,幼苗根诱导的最适培养基为1/2MS+IBA0.3mg·L-1。随着培养时间的延长,生根率会不断提高,培养到30d,生根率可达100%。     

对生玉米离体培养再生体系的建立

以对生玉米的雌、雄幼穗为外植体,研究了不同质量浓度激素及其组合对愈伤组织诱导、再分化苗和试管苗生根的影响,建立了对生玉米离体培养再生体系。结果表明：长度为15-17 mm的雌、雄幼穗能够诱导出质量较好的愈伤组织,但只有来自于雄幼穗的愈伤组织才能再生成苗。适合愈伤组织诱导的培养基为Ms+1．5-2．0 mg·L-12,4-D+0．5 mg·L-16-BA+0．5 mg·L-1 NAA+500 mg·L-1脯氨酸+1000 mg·L-1水解酪蛋白+30 g·L-1蔗糖;适合愈伤组织再分化培养基为MS+1．5-2．0 mg·L-1 6-BA+0．1 mg·L-1 NAA+500 mg·L-1水解酪蛋白+30 g·L-1 蔗糖;适合试管苗生根培养基为1／2 MS+0．25-0．5 mg·L-1 IBA+20 g·L-1蔗糖。     

梨枣叶片和茎段再生体系的建立

用不同浓度配比的生长素和细胞分裂素诱导梨枣叶片和茎段愈伤组织的产生,并研究了不定芽诱导的最佳配方,建立了梨枣叶片和茎段的再生体系.结果表明,梨枣叶片愈伤组织诱导的最佳培养基为MS+2,4-D 1.5 mg·L-1+6-BA 0.5 mg·L-1;茎段为MS+2,4-D 1.0 mg·L-1+6-BA 0.5 mg·L-1.叶片不定芽诱导的最佳培养基为MS+IBA 0.1 mg·L-1+6-BA 1.5 mg·L-1. AgNO3能阻止叶片外植体褐化并有效地促进叶片愈伤组织分化.茎段能在同一培养基上产生愈伤组织并直接分化出不定芽.     

崖白菜的愈伤组织诱导及植株再生

通过愈伤组织诱导不定芽发生途径,建立了崖白菜的组培再生体系,研究了崖白菜幼嫩子房和不同植物生长调节剂对其愈伤组织诱导和不定芽发生的影响。结果表明,以崖白菜的幼嫩子房作为外植体,诱导子房分化形成愈伤组织的最适培养基为MS＋6．BA1．0mg·L-1＋2,4-D0．2mg·L-1,诱导率可达82．83％;最适的不定芽分化培养基为Ms＋6-BA0．5mg·L-1＋NAA0．1mg·L-1;诱导不定芽生根的最适培养基为1／2MS＋NAA0．1mg·L-1。     

裸果木再生体系建立与不定芽发生研究

为探究裸果木再生体系建立的影响因素,确定其不定芽发生的起源,该研究以裸果木健壮植株的茎段为外植体,采用6 BA和IBA不同浓度组合,筛选愈伤增殖及不定芽再生的最佳浓度组合,确定生根诱导的关键影响因素,建立再生体系,并对其不定芽分化进程进行解剖结构分析,以确认其起源。结果表明：(1)裸果木茎段的最佳愈伤增殖培养基为MS+1 mg·L^-1 IBA+1 mg·L^-1 6 BA+30 g·L^-1蔗糖+7 g·L^-1琼脂,主体间效应分析表明IBA为关键影响因素;愈伤大小随IBA浓度增加呈现先升高后下降的趋势。(2)最佳不定芽诱导培养基为MS+0.5 mg·L^-1 6 BA+30 g·L^-1蔗糖+7 g·L^-1琼脂,诱导不定芽数量为4.9个/块,生芽率达92.3%。(3)生根诱导中,SH基本培养基和蔗糖浓度为关键因素,最佳生根培养基为SH+0~10 g·L^-1蔗糖+7 g·L^-1琼脂,生根率达91.3%。(4)解剖结构观察发现,不定芽起源于愈伤表层的分生细胞,为外起源。该研究通过器官发生途径建立了裸果木的再生体系,确定了不定芽为外起源,为裸果木这一珍稀濒危的林木种质资源保护及可持续利用奠定了研究基础,并为其未来的发展利用提供了有效途径。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.