大豆的基因组研究及其进展

大豆是世界上食用油和种子蛋白的主要来源之一,是重要的经济及粮食作物,因此, 大豆的遗传研究一直受到广泛的重视.但是,由于大豆的遗传变异程度低,基因组较大且复杂以及染色体都很小、进行细胞遗传研究难度大等,大豆的遗传研究,尤其是遗传作图研究,与其它作物相比较为落后.     

大豆转基因体系的研究进展

从大豆的转基因方法和受体系统两个方面概述大豆转基因体系的最新研究进展,并讨论了大豆遗传转化的主要障碍及可能的解决途径。作者认为,以根癌农杆菌介导大豆子叶节和基因枪轰击大豆未成熟子叶是较有效的大豆遗传化系统。目前,在大豆遗传转化研究中存在着大豆组织培养体系有待于进一步完善、遗传转化率较低、重复性差、大豆受体基因型单一等问题,建立新的、高效和稳定的大豆组织培养体系,提高生产上栽培大豆品种的组织培养能力,改遗传转化现有的单一基因为多基因,可能是解决上述问题的有效途径。     

大豆遗传转化技术在转基因大豆研究中的应用

大豆是公认的难转化的作物,大豆的遗传转化还没有模式化。利用转基因技术的原理和方法,对大豆遗传体系进行优化,可以实现对大豆产量和品质的改良。综述了应用于大豆遗传转化的研究方法,浅谈转基因技术的重要性,对转基因发展方向进行了展望。现阶段大豆遗传转化的效率依旧偏低,无法形成规模化的转基因体系。因此,建立高效、快速、稳定的大豆组织培养再生体系,解决外源基因难导入的难题,使之广泛应用于大豆生产成为亟待解决的问题。     

大豆种质资源遗传多样性研究进展

我国拥有丰富的大豆种质资源,大豆种质资源遗传多样性研究也取得了较大进展。总结了近年来大豆种质资源组成、保存、研究、利用等几方面的研究进展,讨论了大豆遗传多样性的重要性和发展方向,以期为大豆优良品种培育相关研究提供参考。     

江淮下游地区大豆地方品种的初步研究——Ⅱ.数量性状的遗传变异

本文研究江淮下游地区大豆地方品种有关生育期、产量、机械化栽培共17种数量性状的遗传变异。根据这些性状的表型和遗传型方差、遗传型变异系数及遗传力,估计预期遗传进度,从而揭示从大豆地方品种自然群体进行选择的潜力和预期效果。研究证实了本区大豆地方品种数量性状的遗传资源非常丰富;系统育种仍是大豆育种主要方法之一,应加以重视;并提出用数量遗传方法整理和研究大豆地方品种是育种理论和实践上都有意义的方法。     

大豆籽粒吸水遗传规律的探讨

对栽培大豆、野生大豆及其杂交后代籽粒进行吸水遗传规律的研究。结果表明：大豆籽粒吸水属于数量性状遗传,是由多基因控制的,吸水为显性,不易吸水为隐性,并且表现细胞质遗传效应和亲本效应。     

大豆转基因的研究进展

近年来利用基因工程技术,大豆的遗传转化取得了较大的进展。该文介绍了几种主要的大豆遗传转化系统的优点和缺点。探讨了影响农杆菌介导大豆遗传转化的因素。分析了大豆遗传转化中存在的一些问题及其解决办法,评价了转基因大豆的生物安全性,展望了未来大豆遗传转化的发展前景。     

不同尺度下野大豆种群的遗传分化

为了阐明不同尺度范围内野大豆种群的遗传分化情况,应用随机扩增多态性DNA（RAPD）方法,分别对我国5个纬度8个不同地点的野大豆（Glycine soja)种群及浙江金华地区5个野大豆种群,进行了分子生态学研究。根据RAPD数据计算相似系数及遗传距离并进行聚类分析,发现无论是不同纬度野大豆种群还是金华地区野大豆小种群均存在较高的遗传变异,且不同纬度野大豆种群间的遗传变异与地理纬度有一定正相关。在对金华地区野大豆种群遗传多样怀的研究,利用Shannon指数估算了5个野大豆种群的遗传多样性,发现大部分的遗传变异存在于野大豆种群间（78．5％）,只有少部分的遗传变异存在于种群内。本就此探讨了不同尺度下野大豆种群的遗传多样性与环境因子的关系,并对其成因及维持机制进行了讨论。     

大豆遗传转化研究进展

综述了大豆遗传转化体系及其优缺点,转基因大豆的研究成果、生产状况和生物安全性评价,分析了大豆遗传转化中存在的一些问题及其解决办法,展望了未来大豆遗传转化的发展前景。     

大豆炸荚发生规律及分子遗传基础

炸荚是野生大豆繁衍后代的一种原始自然属性,同时也是栽培大豆减产的主要原因之一,因此对其发生规律和分子遗传基础的研究具有重要的理论意义和潜在的育种应用价值。文章在剖析抗炸荚大豆荚部细胞学微观组织结构特征的基础上,总结了大豆炸荚的发生规律和大豆炸荚表型性状的鉴定指标与方法,介绍了抗炸荚种质鉴定与抗炸荚品种选育概况,同时详细阐述了大豆抗炸荚性状的分子遗传基础研究进展,最后对大豆抗炸荚性的研究与应用进行了展望。     

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.