TMV弱毒DN60—3的诱变及其对番茄花叶病的保护效果试验

为获得TMV弱毒,在选择轻症纯毒系的基础上,以亚硝酸诱变处理30、40、50、60分钟,得到了30个无症突变株,经室内交叉保护试验,其中DN60-3对TMV的重花叶株系、条斑株系和山东济南的坏疽型都有显著的干扰作用,而对生产影响不大的黄色花叶株系和黄色环斑株系的干扰作用差。田间试验示范结果,对保护地栽培的番茄花叶病(包括卷叶病)的防病增产效果明显。同时发现,栽培技术差,植株长势弱,则保护放果减低。由于弱毒的保护作用属于持异性免疫,因此,在弱毒应用上,对TMV和CMV混发地区的露地番茄无保护作用。随着抗TMV番茄品种的全面推广,弱毒的利用将会失去重要性,目前一些中小城市番茄品种正处于更新时期,弱毒仍可发挥一定作用。     

应用烟草花叶病毒弱毒疫苗N_(14)和卫星核糖核酸生防制剂S_(52)防治番茄病毒病的试验研究

1983—1986年的试验结果表明,应用烟草花叶病毒(TMV)弱毒疫苗N_(14)和黄瓜花叶病毒(CMV)卫星核糖核酸生防制剂S_(52)二联接种免疫番茄,能有效地防治TMV和CMV对番茄的危害。其结果是:经过免疫的番茄比不免疫的番茄病株率下降25.2～45.4％;病情指数下降16.1～31.3;每亩增产率达到22.3～44.9％。 1986年山西省大面积示范约958亩,增产幅度也均在20％以上。     

百合不定芽培养脱毒种球生产的研究

百合不定芽培养再生植株的病毒脱毒效果因百合品种和病毒种类而有所差异;‘卡萨布兰卡’百合潜在病毒(LSV)容易脱去,脱毒率达76％,‘魅丽’黄瓜花叶病毒(CMV)能全部脱去。‘卡萨布兰卡’不定芽培养在固体培养基和液体培养基都能很好形成子球;在含有抗病毒剂(10mg／L DHT)的液体培养基中子球增大显著,LSV脱毒效果理想。无病毒子球移到有防虫网的户外栽培,2年后部分植株被检测出病毒,再感染率因品种而不同,‘卡萨布兰卡’高达73％,麝香百合‘乔治亚’仅17％;无病毒植株‘乔治亚’．香华丽百合和‘卡萨布兰卡’的生长高度要比有病毒植株明显增高。     

表达黄瓜花叶病毒外壳蛋白的转基因番茄抗黄瓜花叶病毒侵染

通过土壤农杆菌(Agrobacterium tumefaciens)介导将黄瓜花叶病毒外壳蛋白(CMV CP)的cDNA成功地引入番茄(Lycopersicon esculentum)植株中,并得到转基因植株。用强致病力CMV株系接种后,表达CMV外壳蛋白的转基因植株表现出对CMV侵染的抗性。转基因植株RI代的抗性基因以接近3:1比例分离。对R_1代接种CMV后,表达CMV CP的植株病症减轻,发病率、病情指数及病毒积累量明显低于对照。病症出现推迟1个多月。     

安徽烟草病毒类型及优势种初步研究

1978年,烟草病毒病在安徽烟区流行,导致凤阳县烟叶总产损失92.3％,引起了普遍震惊。1981—1984年作者对来自16个县、市552个病毒材料,经生物测定、血清反应、电镜观察,初步分离出CMV、TMV、PVY和PVX四种病毒。它们分别约占检测总数的82.79％、4.53％、2.54％和0.36％,其中CMV与长期视为优势种的TMV比值为18.3,除此,尚有约占检测总数9.8％的CMV和TMV、CMV和PVY复合侵染,以及不明类型的毒株。通过对田间烟草以及其他植物花叶病株的实际检测,进一步表明:CMV在烟区分布范围极广、出现频次最多,已形成了复杂的循环侵染系统,成为近期内烟草病毒病持续流行危害的首要毒原。     

延边地区烟草病毒种类及病毒病的防治

对田间烟草进行病毒病种类的调查和鉴定结果表明,延边地区感染烟草的病毒主要是烟草花叶病毒(TMV)和黄瓜花叶病毒(cMV),而以两种病毒的混合侵染为主,达80-1 00％。弱毒疫苗N14．和CMV卫星RNA生防制剂S5,混合使用,或CMV卫星RNA生防制剂S512单独使用防治烟草病毒病,与不使用的对照比较,防治效果明显,达70.2—77.1％,上等烟比率达22.3—30.9％,而对照只有9．2-1 9.2％,亩收入比对照增加21．7—8 0.8％。     

抗花叶病烟草种质资源的鉴定与筛选

本研究以不同来源、不同类型的46个烟草品种为试验材料,进行抗烟草普通花叶病（TMV）特性的田间鉴定和分子鉴定,为筛选抗病烟草种质奠定基础。结果表明,22个品种的烟草抗TMV特性田间鉴定结果与前人鉴定结果基本相同,从24个前人未鉴定的烟草品种中初步筛选出14个中抗品种,8个中感品种和2个感病品种;通过抗TMV基因（CN）的特异引物进行扩增,36个烟草品种的基因组DNA具有特异性片段;通过分子鉴定和田间鉴定的结果比较,62.9%的具有CN或其同源基因的烟草品种田间鉴定表现为中抗或高抗,83.3%的具有CN或其同源基因的选育烟草品种田间鉴定表现为中抗或高抗;结合两种方法,初步确定了3个中感品种和11个中抗品种。     

重庆地区新收集烟草种质资源的鉴定评价与整理编目

为将"第三次全国农作物种质资源普查与收集行动"重庆项目组收集到的63份烟草种质资源入国家种质资源库进行编目和保存,对其进行田间鉴定和拍照记录。形态特征和主要农艺性状的遗传多样性分析表明,供试种质的数量性状和质量性状遗传多样性丰富,质量性状以叶形的多样性指数最高,数量性状中叶长、叶宽和茎围的多样性指数较高。聚类分析将新收集烟草种质资源分为4个类群,其中第Ⅰ类群以黄花烟为主,第Ⅲ类群的植株最高、叶片最大,可用于高产育种。主要病毒病的抗性鉴定发现,有11份种质TMV和CMV的抗性均较强,其中2份种质对TMV免疫且高抗CMV,可用于抗病育种。另外,通过田间表型和SSR分子标记对拟编目资源进行鉴定整理,剔除了重复的种质资源。因此,烟草种质资源的普查收集工作对于丰富国家烟草种质资源库和新品种选育具有重大意义。     

Fuzzy相关综合评判模型在辣椒品种抗病毒病鉴定中的应用

本文以辣椒苗期对烟草花叶病毒(TMV)和黄瓜花叶病毒(CMV)的抗性作评判因子,应用Fuzzy相关综合评判模型,对品种田间抗病毒性表现进行评判。结果表明:与田间抗病毒性表现符合率为92.31%,说明该方法具有较高的可靠性,可作为其他作物抗病性鉴定的借鉴。     

Fuzzy相关综合评判模型在辣椒品种抗病毒病鉴定中的应用

本文以辣椒苗期对烟草花叶病毒(TMV)和黄瓜花叶病毒(CMV)的抗性作评判因子,应用Fuzzy相关综合评判模型,对品种田间抗病毒性表现进行评判。结果表明:与田间抗病毒性表现符合率为92.31%,说明该方法具有较高的可靠性,可作为其他作物抗病性鉴定的借鉴。     

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.