表油菜素内酯对月季切花保鲜作用的研究

本文初步探讨了表油菜素内酯（epiBR）对瓶插月季切花的保鲜作用。与对照（蒸馏水）和基本液（2％蔗糖＋500mgL-1柠檬酸＋250mgL-8-羟基喹啉＋25mgAgNO3）相比,经epiBR处理（基本液＋0．1mgL-1epiBR）的月季切花花枝坚挺,蓝变延迟,瓶插寿命延长1-1.5倍。测定有关生理指标表明,epiBR处理对月季切花瓶插花枝前期鲜重的增加及后期的保持有明显作用。并显著延缓花瓣和叶片质膜相对透性的增加,还能使瓶插前期花瓣还原糖含量增加。epiBR处理对花瓣蛋白质和叶片叶绿素含量变化无明显影响,而对花瓣花青素水平下降有轻微的促进作用。     

1-MCP对东方百合开放与衰老的影响

以东方系列百合（Lilium spp.）‘西伯利亚’品种为材料,研究了1-甲基环丙烯（1-MCP）对百合切花质膜透性、乙烯释放量、丙二醛含量、可溶性蛋白质含量等生理指标的影响。结果表明：1-MCP可延缓百合切花花瓣质膜相对透性的增加,延长百合切花瓶插寿命;降低百合花瓣乙烯释放量,推迟乙烯峰的出现;降低百合花瓣丙二醛含量,对可溶性蛋白含量的变化无明显影响。本研究结果说明1-MCP对东方百合切花的保鲜有一定效果,确定了1-MCP处理东方百合的最佳使用浓度为0.01μL/L。     

不同保鲜剂对非洲菊切花的保鲜效应

探讨不同保鲜剂对非洲菊切花的瓶插寿命、观赏品质以及生理生化指标的影响。结果表明,在供试7组保鲜剂中,以处理7(T₇):20g/L Suc+200mg/L 8-HQC+150mg/L CA+75 mg/L KH₂PO₄·3H₂O+1g/L CaCl₂的保鲜效果最佳,可显著延长非洲菊切花瓶插寿命;T₇处理有利于减缓花瓣组织pH上升、花青素含量下降及花瓣细胞膜相对透性的上升,从而延长瓶插寿命。     

烯效唑（S-3307）对非洲菊切花保鲜的影响

以非洲菊(GerberajamesoniiBolus)切花为材料,以保鲜基本液(BP,20gL-1蔗糖 200mgL-1柠檬酸 150mgL-18-羟基喹啉柠檬酸盐)和添加30mgL-1烯效唑(S-3307)的基本液(BP S-3307)作对比实验,通过对切花外部形态观察和切花衰老过程中一些生理生化指标测定,探讨了S-3307对非洲菊切花的保鲜效果。结果表明,S-3307处理使切花的瓶插寿命比对照(蒸馏水)延长了4.3d,比BP处理延长了2.3d,而弯颈率分别仅为对照和BP处理的9.6%和28.8%。说明S-3307可增强切花的吸水能力,增加花枝的鲜重,延缓了切花花瓣中蛋白质的降解和抗氧化酶SOD和CAT活性的下降,并减少了游离脯氨酸和MDA的积累,维持膜结构的相对稳定性,从而延缓了非洲菊切花的衰老和提高了切花瓶插期间的观赏品质。     

保鲜剂对夏季香石竹切花衰老的延缓作用

香石竹切花瓶插期间花瓣中ＳＯＤ和蛋白质在前期上升,然后比处理组提前３天呈下降趋势。采后花瓣中ＣＡＴ、可溶性总糖和蔗糖均为下降。经由蔗糖、８－羟基喹啉和植物生长调节剂或钴镍盐组成的保鲜剂能延缓切花花瓣中ＳＯＤ、ＣＡＴ活性的下降,阻碍蛋白质、可溶性总糖和蔗糖的降解速度,同时使切花的瓶插寿命延长、含水量增加。     

青霉素和比久对月季切花保鲜效应的研究

切花保鲜的关键技术是降低水分的散失和防止营养亏缺。以月季为材料,采用室内瓶插的方法研究 了青霉素和比久对切花保鲜的效应。结果表明:含不同浓度青霉素和比久B9的保鲜剂均能延长月季切花的 瓶插寿命,增加切花鲜重,增大花径,提高花瓣过氧化物酶(POD)的活性,改善切花体内水分状况,维持花瓣膜 结构的相对稳定。青霉素处理对提高月季切花保鲜品质的效果好于B9。     

杀菌剂和低温贮藏对芍药切花保鲜及其生理变化的影响

利用杀菌剂及低温贮藏对切花芍药‘婴粟子’的抑菌效果、瓶插寿命、开花率及其生理变化进行了研究。结果表明,不同浓度杀菌剂均有一定的抑菌作用,并且处理Ⅲ（1000mg／kg甲基托布津＋1000mg／kg多菌灵）效果最好。预冷处理可以降低切花的呼吸速率,延长瓶插寿命和贮藏保鲜期。随着低温贮藏时间的延长,切花鲜重和开花率下降,花瓣的细胞膜透性和MDA含量增加,蛋白质含量下降,呼吸速率呈跃变型变化。     

玫瑰切花保鲜剂配方研究

以蔗糖(S)、8-羟基喹啉(8-HQ)、柠檬酸(CA)为保鲜液的基本配方,分别加入CaCl2 、NaCl、Al2(SO4)3、CaCl2+KAl(SO4)2 组成四种保鲜液,进行玫瑰切花保鲜实验。对切花瓶插寿命、花径、水分平衡值、可溶性蛋白含量和还原糖含量进行分析。结果表明,各种配方保鲜液均能延长玫瑰切花的瓶插寿命、增大花径、改善切花水分代谢状况、降低切花蛋白质和还原糖的分解速度。其中,保鲜液2% S + 280 mg/L CA + 200 mg/L 8-HQ + 1% CaCl2的保鲜效果最好。     

不同保鲜剂对月季切花的保鲜效应

本试验研究不同保鲜剂对月季切花瓶插寿命、观赏品质的影响。正交试验表明,在供试保鲜剂的9个组合中,配方7(P₇)[0.2% Ca(NO₃)₂+0 Suc+400mg/L B₉+1mmol/L STS]保鲜效果最好,可明显延长月季切花瓶插寿命;以P₇保鲜剂喷洒花瓣可促进花朵生长发育;月季切花在瓶插过程中,其花瓣组织的pH值随切花的衰老而上升。     

氯化钙对非洲菊切花的保鲜作用

以 1 0mg ml的CaCl2 溶液作为保鲜液 ,对非洲菊切花进行瓶插试验 ,通过外部形态观察和生理指标测定 ,结果表明 :用CaCl2 溶液瓶插非洲菊切花可以增强花枝的吸水能力 ,增加花枝的鲜重 ,保持切花的水分平衡 ,减少溶质外渗 ,维持膜结构的相对稳定性 ,从而使切花的瓶插寿命比对照延长 3 3d。     

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.