红掌组织培养污染率控制研究(简报)

为解决红掌组织培养过程中污染率较高的问题,就降低组织培养污染率的措施进行了研究。结果表明,在继代培养的固体培养基中加入5～20 mg/L硫酸阿米卡星,污染的培养基表现为无菌状态,试管苗生长正常。     

迷你玫瑰组织培养中细菌污染的防止

迷你玫瑰组织快繁体系连续继代过程中,插入培养基的试管苗切口处有云雾状污染菌生长,其中2种为革兰氏阴性杆菌,1种为革兰氏阳性杆菌.培养基中加入氨苄青霉素(50～150 mg·L-1)抑制污染菌生长,不影响试管苗不定芽分化率,50 mg·L-1的氨苄青霉素明显促进染菌苗的生根.加入硫酸丁胺卡那霉素(25～100mg·L-1)有杀灭污染菌的作用,但对试管苗则有不同程度的毒害(叶片、叶柄和茎段出现黄化现象),对不定芽分化和生根也有明显的抑制.     

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％．     

草莓的组织培养与快速繁殖研究

通过对草莓的茎尖生长点进行组织培养,获得草莓脱毒苗,并以此为试材,对草莓的快速繁殖以及生根培养进行了研究。结果表明：芽的最适诱导分化培养基为MS BA0．5mg／L IAA0．05mg/L,诱导率可达70％;最适增殖培养基为MS BA0．2～1．0mg／L,增殖倍率可达3．2;试管苗在1／2MS附加IAA0．5me／L的培养基上,经过10～15d的培养,95％生根成苗。     

防风组织培养中畸形胚状体的发生和控制

采用组织培养和石蜡切片法,分析多种因素对防风畸形胚状体发生和发育过程的影响及控制。结果表明,诱导正常体细胞胚高频发生的培养基组合是：启动胚性愈伤组织的培养基是MS 0．5mg／L 2．4-D,蔗糖浓度3％;分化培养基是MS 1mg／L 6-BA 0．2mg／L NAA 0．5mg／L ABA,蔗糖浓度4％～5％;成熟培养基是MS培养基,蔗糖浓度3％。结论：一定浓度的生长素是诱导防风胚性愈伤组织的关键因素,细胞分裂素在体细胞胚的分化和发育过程中起协同作用;蔗糖浓度、ABA、接种方法以及适宜的培养条件和培养容器等均可有效降低畸形胚状体的发生率。     

甜橙成熟果实未发育胚珠的离体培养

路比血橙和锦橙成熟果实的未发育胚珠在含ME(1000mg/l)的MT培养基上培养,胚状体诱导率和每个胚珠平均产生胚状体数均较高。带胚状休的愈伤组织转入该培养基上继代培养,仍可保持其胚性特点。将子叶形胚状体转至含GA(1mg/l)和CH(500mg/l)的MT培养基上,成苗率较高。这为扩大柑桔组织培养的外植体来源和克服外植体的季节限制提供了新途径。     

根癌土壤杆菌介导转化诸葛菜子叶获得转基因植株

采用诸葛菜子叶为材料。在MS+BA 3mg／l,+NAA O．2mg／L培养基上诱导芽的再生,1／2 MS+IBA 0．03mg／L．上诱导生根,获得完整再生植株,建立了诸葛莱组织培养高频再生系统,其再生率可达100％。采用土壤杆菌介导转化诸葛菜子叶．在附加一定量的氨苄青霉索、头孢霉素和卡那霉素的相应培养基上进行筛选,进而培养出再生成苗。获得完整植株,经GUS和NPTI酶活测定,以及Southern blot分析．证实为转基因植株。转化子叶的芽再生率为51％．获得完整转基因植株的转化率为5．53％。在国内外首次建立了以根癌土壤杆菌(Agrobacterium tumefaciens)为载体,诸葛菜子叶为受体的遗传操作系统。     

澳洲青苹组织培养再生体系的研究

通过对澳洲青苹茎尖培养及植株再生体系中无菌培养物的建立、初代培养、继代培养、生根培养和移栽五个技术环节的研究,建立了澳洲青苹组织培养快速繁殖技术体系。结果表明：(1)BA0．3～0．6mg／L NAA0．1～0．3mg／L的MS培养基能促进澳洲青苹茎尖生长或大量侧芽的分化,不定芽生长健壮;(2)无根幼苗在含有IBA0．6～1．0mg／L NAA0．1mg／L的1／2MS培养基上暗培养一周后,再进行自然光培养,30d生根率可达到78%以上;(3)生根苗经50mg／L NAA浸渍1～2h后,移入蛭石：腐殖土：田园土=2：1：1的移栽基质中,保温保湿,成活率达80％以上;(4)进一步建立了自然光下生根、练苗一次完成的同步化体系,缩短了繁育时间,简化了步骤,降低了成本。此技术体系为澳洲青苹优良种苗快速繁殖提供了一条新途径。     

‘香槟’月季的组织培养和试管开花诱导

本文对‘香槟’月季（80sachinensis‘Xiangbin’）的组织培养技术和诱导试管开花进行了研究。结果表明：以茎段为外植体能诱导获得无菌苗,适宜的启动培养基为MS＋6-BA1．0mg-L-1＋IBA0．1mg·L-1,幼芽继代增殖的最佳培养基是MS＋6．BA1．0mg·L-1。＋IBA0．1～0．2mg·L-1,诱导生根的适宜培养基为1／2MS＋NAA0．3mg·L-1,生根率达80．0％。诱导试管开花的适宜培养基为MS＋6．BA0．5mg·L-1＋NAA0．1mg·L-1最适宜的诱导试管开花的蔗糖含量是30g·L-1;在三角瓶中培养,试管花可以正常开放,在培养瓶中培养花芽不能正常开放;MS培养基中增加2倍磷的含量,可以提高花芽诱导率,为25．O％;诱导试管开花的最适培养条件为温度21℃,光照强度80～100μmol·m-2．s-1,光照时间16h—d-1。     

基因型和培养条件对大麦花药培养的影响

不同基因型大麦(Hordeum vulgare)的花粉愈伤组织诱导率不同。带大麦黄花叶病抗性基因的品种、品系或F_1杂种的诱导率(8.83—14.21％)高于不带抗性基因的材料(1.04～6.25％)。MS基本培养基舔加2,4-D,1 mg/l,Kt0.1 mg/l,BA0.2 mg/l,生物素0.1 mg,其诱导率(平均11.0995)高于MS添加2,4-D3 mg/l和Kt0.1 mg/l的诱导率(6.33％)及MS添加2,4-D 1 mg/l和Kt0.1 mg/l的诱导率(8.21％)。接种后先15℃暗培养5天,再转入25℃暗培养,其产生愈伤组织的高峰期推迟2—4天,但诱导率却从对照的5.84％提高到11.59％;25℃暗培养与25℃光-暗交替培养,诱导率无显著差异。     

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.