多变小冠花(豆科牧草)原生质体和外植体胚状体的形成和植株的再生

EM-5游离大量的多变小冠花实生苗子叶原生质体。Kao的原生质体培养基使子叶原生质体分裂形成细胞团。MSD_4诱导多变小冠花原生质体愈伤组织产生胚状体、苗和植株的分化。MS-1诱导多变小冠花实生苗根、下胚轴和子叶愈伤组织的形成,胚状体、苗和值株的分化。根愈伤组织胚状体形成的频率(60%)高于子叶和下胚轴的(<23%)。组织切片的观察表明多变小冠花原生质体植株的再生通过胚状体形成的途径。     

活性染料诱导原生质体凝集的效应（简报）

四种活性染料对绿豆下胚轴、向日葵子叶及下胚轴等三种来源原生质体的凝集效应是;酚番红花红>甲基蓝>中性红>伊文斯蓝。绿豆下胚轴原生质体凝集率明显高于向日葵下胚轴并易形成多聚体。向日葵下胚轴原生质体凝集率又明显高于子叶。酚番红花红、中性红除了可作为原生质体活力指示剂外,还可作为凝集诱导剂和标记物。应用酚番红花红观察到绿豆和向日葵异源原生质体的凝集。     

马铃薯实生苗子叶和下胚轴原生质体培养的研究

在植物原生质体培养中,供体组织的来源对于原生质体游离的难易、原生质体的质量、分裂能力、植板效率以及愈伤组织分化苗的频率都有很大影响,与分化植株染色体倍性的稳定性关系也较大。据报道,在马铃薯中,曾用来作为游离原生质体的供体组织的来源有:温室生长植株顶部刚伸展的幼嫩叶片、试管离体培养苗继代培养1个月左右的幼嫩茎和叶片(现为大部分研究者所采用)、离体培养产生的微型薯、根尖、以及悬浮培养的无叶绿素的叶片细     

狗头枣叶片原生质体分离研究

以培养25d的狗头枣试管苗叶片为材料,研究了不同酶液浓度,不同甘露醇浓度对狗头枣组培苗叶片原生质体分离的影响.结果表明适合狗头枣组培苗叶片原生质体分离的适宜酶液配比为1.0 g/L纤维素酶、0.4 g/L果胶酶,0.6 mol/L甘露醇,黑暗条件下,酶解8h,可获得大量有活力的原生质体.其叶片原生质体的产量为2.12×106个/g,活原生质体获得率为80.88％.     

大豆子叶原生质体游离和培养因子的研究

大豆悬浮培养细胞原生质体的游离和培 养。3,13,203及遗传操作应用的研究“,7,8,11,15,21,25,已 有报道。近年来,一些学者直接从大豆植株的 不同器官或部位如豆荚组织〔271、幼苗根[261、叶 肉[22,24,和子叶『2,19,游离和培养原生质体获得好 的结果。本试验叙述大豆实生苗和未成熟种子 两类子叶原生质体游离和培养因子的异同,以 利于子叶原生质体遗传操作应用和植株分化的 进一步研究。     

芥菜原生质体培养和植株再生

从芥菜无菌苗的下胚轴和子叶游离获得原生质体,在含1.5毫克/升NAA、0.6毫克/升BA和0.5毫克/升2.4-D的DPD液体培养基中静置培养。试验表明,经13℃低温预处理不仅能够提高原生质体的分裂频率,而且能够加速原生质体的发育进程;除木糖外,葡萄糖、甘露醇和山梨醇均可作为原生质体培养初期的渗透稳定剂。来源于下胚轴原生质体的愈伤组织在含3毫克/升BA、0.1毫克/升GA_3或3毫克/升BA的MS培养基上诱导出了芽,含0.05毫克/升IBA的MS培养基上诱导出根,从而获得了完整植株。     

油橄榄下胚轴诱导完整植株

油橄榄离体茎培养出根已有报道,但无诱导完整植株的试验结果。我们以油橄榄下胚轴、子叶、胚根、嫩茎、茎尖和叶片等作为外植体进行了试验,除从茎尖诱导发生小植株外(待发表),在下胚轴上也已诱导出完整植株。从甘蓝下胚轴诱导发生小植株已有报道,本文就油橄榄下胚轴诱导完整植株作简要报道。油橄榄(Olea europaea L.)种子经消毒处理后,通过无菌培养得到无菌苗。在幼苗下胚轴伸长到2—3厘米时,在无菌条件下切除茎尖、子叶     

新疆杨叶肉原生质体游离和纯化的研究

以新疆杨(Populus albaL.var.pyramidalis)无菌苗叶片为材料,就其原生质体游离、纯化方法及影响因素等进行了研究。结果表明,cellulase R-10、hemicellulase和pectolase Y-23对原生质体产量有极显著影响。适宜新疆杨叶片原生质体游离的条件为CPW KM8P 3.0?llulase R-10 0.5%~1.5%macerozyme R-10 0.5%hemicellulase 0.1%~0.5%pectolase Y-23 0.6 mol/L甘露醇,酶解温度27℃,酶解时间8 h。在此条件下,原生质体产量达1.57×107个/gFW,活力79.41%,而且蔗糖等密度离心法中的上浮法纯化原生质体效果最佳,最适蔗糖浓度为30%。     

霸王的原生质体培养的研究

目的：为利用原生质体融合技术转移霸王抗旱基因。方法：采用酶解法分离霸王原生质体,比较了霸王子叶和愈伤组织游离原生质体的产量和活力,不同渗透压和起始密度对原生质体分裂频率的影响。结果：愈伤组织游离的原生质体产量和活力均高于子叶,原生质体产率可达2.4&#215;106个/g.FW,活力达89%。采用液体浅层培养,在附加2,4-D（2mg/L）、6-BA（1.0mg/L）、2%蔗糖和甘露醇（0.4mol/L）的DPD培养基中,原生质体分裂频率最高,达68.6%。转移到附加2-iP（3mg/L）、KT（1.0mg/L）、6-BA（1.0mg/L）的分化培养基上,获得2个再生苗。结论：采用酶解法游离霸王愈伤组织,可获得高活力和高分裂频率的霸王原生质体。     

槐树试管正常苗与超度含水态苗茎叶的比较形态学研究

槐树(Sophora japonica L.)子叶经培养获得了大量的试管苗,依其形态正常与否可将其分为正常苗、超度含水态苗和介于二者之间的过度含水态苗。其自由水含量明显不同,正常苗低于50％,超度含水态苗高于79％,而过度含水态苗约为70％。以扫描电镜对其茎、叶的形态学结构进行了比较研究,结果表明:正常苗茎、叶表皮结构基本类似于实生苗,而过度及超度含水态苗的茎、叶表皮层结构变异较大。主要表现在其表面凹凸不平,表皮层外稀有或无蜡质存在,表皮细胞形状及排列不规则,叶片近、远轴两面气孔器密度、大小及开度均较正常苗显著增大;保卫细胞形态、结构异常。上述特征,均显示出槐树试管过度及超度含水态苗易失水干化,这可能是其在移栽过程中难以成活的主要原因之一。     

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.     

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     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.