紫薯提取物对花叶芋试管苗生长的影响

实验以花叶芋无菌苗为材料,通过研究有机提取物种类,提取物浓度及提取物提取方式对花叶芋试管苗生长的影响,筛选出最适合花叶芋试管苗培养的天然有机提取物。实验结果表明：MS基本培养基中添加紫薯提取物时,花叶芋试管苗生长优于其他植物提取物;当紫薯提取物浓度为10％时,花叶芋试管苗长势最佳;比较紫薯上清液、沉淀物、混合液3种提取方式,紫薯混合液对花叶芋的生长最为有利。     

花叶芋的组织培养和植株再生

双色花叶芋(Caladium bieolor)和亮白花叶芋(C.hortulanum)的叶及花序外植体在加有2,4-D 和激动素或只加有2,4-D 的培养基上产生了愈伤组织,它们在转移到无激素或含激动素和低浓度生长素的培养基上以后分化出大量胚状体,并进一步长成小植株。本工作为花叶芋的快速繁殖提供了方法。     

两种芋属(天南星科)植物的核型研究

报道了芋属两种植物的核型,结果如下:异色芋2n=2X=28=18m+10sm,属于“2B”类型;花叶芋2n=2X=28=20m(8sat)+8sm(2sat),属于“2A”类型;花叶芋的核型及两个种之间的核型比较系首次报道。     

天南星科观叶植物多

天南星科有2000多种,绝大多数分布在热带、亚热带地区。该科植物耐荫性强,叶片、佛焰苞耐观赏种类丰富,因此拥有众多的室内观叶植物佳品。常见栽培的有龟背竹、广东万年青、花叶芋、合果芋(箭叶芋)、马蹄莲、海芋、绿萝、红宝石喜林竹、绿宝石喜林芋、白鹤芋、花叶万年青等等。其中龟背竹、喜林     

花叶芋(Caladium bicolor)组培的改进及细胞组织学观察

花叶芋(Calalium bicolor),又名五彩芋,属天南星科,是一种美丽的观叶植物,原是通过块茎繁殖,但其休眠期长,增殖速度慢,因此,利用组培扩大繁殖,以满足市场需要。关于花叶芋的组培,已有不少报道,但对合适的培养基的筛选,分化的途径都还有研究的必要。为此,我们以花叶芋叶柄、叶片为材料进行了初步研究现结果如下:1.愈伤组织的诱导和培养基的改进:所用培养基中在 MS 附加2,4-D1ppm,KT 1ppm、     

不同品种花叶芋的组织培养

采用12个不同品种花叶芋的叶片和叶柄进行组织培养,发现不同品种的最佳外植体并不一致,大叶型品种以叶片、小叶型品种以叶柄为佳。试管苗叶片和叶柄比栽培苗的叶片与叶柄更有利于作离体繁殖的外植体。不同外植体对培养基要求则差别不大。花叶芋离体叶片和叶柄在MS+BA 2mg/L+NAA 0.2～0.6mg/L培养基上可直接分化成小芋块,小芋块剖面坚实呈白色,以I-KI溶液染色呈现深蓝色,与盆栽苗芋块相同。小芋块在降低激素浓度培养基即于MS补加BA与NAA各0.1mg/L培养基上,即分化出大量的再生植株。在芋块上分化出芽,在芋块与苗之间分化出根。     

国产芋属花粉形态

通过光镜和扫描电子显微镜观察了芋属(Colocasia Schott)6种、1变种、1品种的花粉形态,其中贡山芋C．gaoligongensis,龚氏芋C．gongii,李氏香芋C．lihengiae,花叶芋C．bic-olor4个种为首次报道。本属花粉为圆球形,无萌发孔。外壁纹饰分为两类：大野芋C．giga-ntea外壁光滑无刺,其余各种均具刺。花粉大小为20．07—32．76μm。     

花叶芋(天南星科)的花器官发生

利用扫描电镜首次观察了天南星科花叶芋(Colocasia bicolor) 的花器官发生过程。花叶芋的肉穗花序由无花被的单性花构成, 雌花发生于花序基部, 雄花发生于花序上部, 中性花位于花序中间部位。雄花: 3 或4 个初生雄蕊原基轮状发生, 随后每个初生原基一分为二, 形成6或8个次生原基; 一部分次生原基在其后的发育过程中融合, 形成5 或7 枚雄蕊; 雄花发育过程中未见雌性结构的分化; 花药的分化先于花丝; 雄蕊合生成雄蕊柱。雌花: 合生心皮, 3或4个心皮原基轮状发生, 未见雄性结构的分化。中性花来源于雌雄花序过渡带上, 属于雄蕊原基的滞后发育以及发育成熟过程中的退化; 与彩叶芋属(Caladium)不同, 此过渡区未见畸形两性花。初生雄蕊原基二裂产生次生原基的次生现象在目前天南星科花器官发生中显得比较特殊, 同时初步探讨了次生原基的融合方式。     

中国芋属植物染色体数目及5个种的核型报道

对中国 8种 (包括 1变种 )芋属 (ColocasiaSchott)植物的体细胞染色体数目和其中 5个种的核型进行了报道。结果分别为 :异色芋C heterochromaH .LietZ .X .Wei,2n =2x =2 8=1 8m 1 0sm ;龚氏芋C gongiiC .L .LongetH .Li,2n =2x =2 8=1 8m (4SAT ) 1 0sm(4SAT) ;贡山芋C gaoligongensisH .LietC .L .Long ,2n =2x =2 8=2 4m 4sm ;李氏香芋C lihengiaeC .L .LongetK .M .Liu ,2n =2x =2 8=1 8m (1SAT ) 6sm 4st;花叶芋C bicolorC .L .LongetL .M .Cao 2n =2 8;紫杆芋C lihengiaeC .L .LongetK .M .Liuvar.nigraC .L .Long 2n =3x =4 2 ;大野芋C gigantea (Bmume)Hookf.,2n =2x =2 8=2 2m 4sm 2st;山芋C konishiiHayata 2n =2 8。除李氏香芋、龚氏芋、大野芋和山芋外 ,其余染色体数目均为首次报道。在核型方面 ,异色芋、龚氏芋、李氏香芋、贡山芋的核型均为首次报道     

花叶芋芽球人工种子研究

将花叶芋(Caladium biocolar)的无菌嫩叶切块,培养在补加有6-BA(1mg/L)、IAA,(0.2mg/L)和CH(500mg/L)的MS琼脂培养基中,20天后在切块的边缘及表面形成圆形淡黄色突起,转移到低激素或无激素的MS培养基上继代培养,形成的深绿色芽球组织,长期保持旺盛的分化能力。芽球用海藻酸钠包裹并在0.1M氯化钙容液中凝聚而成的人工种子胶粒,在无菌培养条件下,成株率可达100％。同时还观察了不同包埋胶、播种条件、芽球质量等对花叶芋芽球人工种子生长的影响。实验表明,对于一些尚不能应用悬浮培养法制备大量体细胞胚的植物来说,芽球组织也是一种制作人工种子的好材料。     

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.