黑莓品种‘Chester’离体培养过程中适宜激素种类和浓度以及光照度的筛选

以黑莓(Rubus spp. )品种'Chester'带腋芽茎段为外植体,对初代培养基、不定芽增殖培养基和生根培养基中适宜的激素种类及浓度进行了筛选,并对增殖培养过程中适宜的光照度进行了研究.结果显示,在初代培养基中添加不同质量浓度的6-BA和NAA对侧芽的萌发和生长有明显的影响,其中,NAA不利于芽的萌发和生长,而添加适量的6-BA可促进芽的萌发和生长;适宜于'Chester'茎段的初代培养基为添加了1.00 mg·L-16-BA的MS培养基(含25 g·L-1蔗糖和5.9 g·L-1琼脂,pH 5.8).单因素实验结果显示,在 'Chester'不定芽的增殖过程中,细胞分裂素主要影响不定芽增殖,而生长素主要影响不定芽生长,以质量浓度低于1.0 mg·L-1的6-BA以及质量浓度低于0.3 mg·L-1的NAA较为适宜;经过进一步的组合筛选,确定适宜于'Chester'不定芽增殖的培养基为添加了0.5 mg·L-16-BA和0.1 mg·L-1NAA的MS培养基(含25 g·L-1蔗糖和5.9 g·L-1琼脂,pH 5.8).在生根培养基中添加高浓度NAA易诱导不定芽基部产生愈伤组织,不利于不定芽生根,因而,'Chester'不定芽适宜的生根培养基为添加了0.10 mg·L-1NAA的1/2MS培养基(含20 g·L-1蔗糖和5.9 g·L-1琼脂,pH 5.8).在不定芽的增殖培养过程中,光照度较强有利于不定芽生长,适宜的增殖培养条件为:光照度3 000 lx、光照时间15 h·d-1、温度(25±2) ℃、相对湿度约70%,此条件下不定芽的增殖系数(1.95)和平均芽长(1.44 cm)最高,芽生长状况良好.     

泰山酸枣离体叶片再生体系的建立

以泰山酸枣叶片为外植体,以WPM为基本培养基,研究了植物生长调节剂种类、浓度及培养方法等因素对离体叶片不定芽再生的影响,结果表明:不定芽启动的最佳培养基激素组合为1.0 mg·L-1 TDZ+0.5 mg·L-1 IAA;不定芽诱导伸长最佳培养基的激素组合为0.1 mg·L-1 IAA+0.5 mg·L-1 GA3.暗培养是不定芽再生的必需条件,在最适宜的不定芽再生培养基上,叶片连续光培养,不定芽不能再生;叶片先进行暗培养3周后转入光下培养,叶片不定芽再生效果最好,再生率最高可达100%.     

蒙古柳的组织培养与快速繁殖

1植物名称 蒙古柳（Salix linearistipularis Hao）,又名筐柳。 2材料类别 无菌苗叶片。 3培养条件诱导愈伤组织培养基：（1）MS＋TDZ0.1mg·L-1（单位下同）＋2,4-D0.01。不定芽诱导培养基：（2）WPM＋6-BA0.1＋NAA0.05。不定芽增殖培养基：（3）MS＋6-BA1.0＋NAA0.05。     

露草的组织培养及植株再生

1植物名称露草(Aptenia cordifolia). 2材料类别种子无菌萌发苗顶芽. 3培养条件种子萌发培养基采用MS基本培养基.不定芽诱导与增殖培养基:(1)MS 6-BA 2.0mg·L-1(单位下同) IAA 0.2;(2)MS 6-BA 0.5 NAA0.05.     

紫茉莉不定芽诱导和植株再生

紫茉莉(Mirabilis jalapa)观赏价值较高,是一种重要的污染修复植物.组织培养技术为植物品种改良和选育的重要途径,但紫茉莉离体快繁方面的研究尚未见有相关报道.该研究以紫茉莉叶片和茎段为外植体,通过观察和统计外植体愈伤组织和不定芽的诱导情况,分析不同植物生长物质对紫茉莉植株再生的影响.结果表明:紫茉莉带芽茎段比较适合丛生芽的诱导,当带芽茎段在MS+1.0 mg·L-16-BA+1.5 mg·L-1 KT+1.0 mg·L-1 NAA+0.05 mg·L-1 TDZ培养基中培养时,不定芽的增殖系数较高.无论是MS或1/2MS培养基,都可诱导不定根的产生,其中生根效果较好的培养基为1/2 MS+0.5 mg·L-1 NAA.该研究结果探索了紫茉莉组织培养的最适条件,根据愈伤组织诱导率和不定芽的增殖系数筛选出了适宜不定芽诱导的培养基类型,根据不定芽生根情况确定了最佳的生根诱导培养基,为建立紫茉莉高效稳定的再生和遗传转化体系奠定了基础.     

杂种甜椒的离体快速繁殖（简报）

甜椒F1子叶柄的不定芽诱导率比子叶尖的高;暗培养5d后转入光照下培养,促进不定芽的形成和缩短培养周期;6-BA5.0mg@L-1与IAA0.5mg@L-1组合的不定芽诱导率较高;培养基中添加水解酪蛋白和AgNO3后,不定芽诱导率降低;增殖培养基中添加15%椰汁明显改善试管苗的玻璃化和脱叶现象.     

黑莓品种‘Arapaho’离体叶片不定芽诱导影响因素分析及再生体系建立

以黑莓(Rubus spp.)品种‘Arapaho’无菌苗叶片为外植体,通过正交和单因素实验分别研究了基本培养基类型、6-BA和1BA质量浓度以及暗培养时间、外植体的叶位和接种方式对不定芽诱导的影响,并研究了IBA质量浓度对不定芽生根的影响;在此基础上,初步建立了黑莓品种‘Arapaho’离体叶片的再生体系.正交实验结果表明:基本培养基类型对叶片不定芽诱导率及平均不定芽数的影响最大,而IBA质量浓度对叶片不定芽诱导率及6-BA质量浓度对平均不定芽数的影响较小;适宜‘Arapaho’叶片不定芽诱导的最佳培养基为含有2.0mg·L-16-BA和1.0 mg·L-1IBA的MS培养基.单因素实验结果表明:暗培养时间、外植体的叶位及接种方式对不定芽诱导率有显著影响;最适宜的暗培养时间为21 d;植株中、上部叶片的再生能力较强,其中第3和第4位叶的不定芽诱导效果最佳;叶面朝上接种更有利于不定芽的诱导.在含0.2 mg·L-1 IBA的MS培养基中,不定芽生根率达100.0％,且根数多、长势良好.黑莓品种‘Arapaho’离体叶片的再生体系为:以无菌苗的第3和第4位叶为外植体,经过适当修剪后叶面朝上接种于含有2.0 mg·L-16-BA和1.0 mg·L-1IBA的MS培养基上,暗培养21 d后置于光照条件下培养30 d;将不定芽转接到含有0.5 mg·L-16-BA和0.3mg·L-1 NAA的MS培养基上进行继代培养;当不定芽高约2 cm时转接到含有0.2 mg·L-1IBA的MS培养基上进行生根培养,最终获得完整植株.     

大叶蚁塔组织培养技术

以大叶蚁塔茎尖作为外植体诱导出无菌苗,再以无菌苗的嫩叶诱导不定芽发生,研究了其离体培养和不定芽再生的过程,成功建立了低成本的快速繁殖技术体系。结果表明:(1)无菌苗增殖培养基为MS+BA 1.0mg·L-1+NAA 0.1 mg·L-1,培养30 d,增殖率稳定为3.80;(2)叶片可直接诱导再生出不定芽,其最佳培养基为MS+ZT 1.0 mg·L-1+NAA 0.1 mg·L-1,诱导率达95%,分化幼苗众多;(3)生根培养基为1/2MS+NAA1 mg·L-1+蔗糖20 g·L-1时,生根率达95%。     

紫芋的组织培养与快速繁殖

1植物名称紫芋（Colocasia tonoimo Nakai.）。 2材料类别地下球茎。 3培养条件不定芽诱导培养基：（1）MS＋6-BA3mg·L-1（单位下同）;不定芽增殖培养基：（2）MS＋6-BA3;壮苗培养基：（3）MS＋PP3330.1;生根培养基：     

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。     

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.