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将不同品种的优良性状通过品种间的杂交集中到一个品种中是育种工作的主要目标,而利用基因型选择代替传统的表型选择将大大加快育种进程和提高育种效率,其中,DNA标记的获得是进行DNA标记辅助育种的重点。随着作物分子标记辅助育种技术的快速发展,苜蓿（Medicago sativa L．）重要性状关联的分子标记研究也取得了很大进展。本文就苜蓿草产量、抗病（虫）害、抗逆性和繁殖特性等主要农艺性状关联的分子标记研究进展进行了综述,主要包括RFLP（DNA－DNA杂交）、RAPD和SSR（PCR）以及AFLP（PCR与限制性酶切技术结合）等分子标记,最后还就苜蓿分子标记辅助育种（marker assisted selection,MAS）所面临的限制因素及其在苜蓿品种改良中的应用前景进行了探讨。 相似文献
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土壤多样性:土壤地理学研究的契机 总被引：5，自引：2，他引：3
介绍了土壤多样性研究的起源、概念及学科意义,在此基础上系统论述了土壤多样性在国内外的主要研究进展和取得的主要成果,并对未来的应用前景进行了展望。首先,生物多样性的保护是以土壤多样性为基础的,保护土壤多样性意义重大,而事实证明广泛应用于生物学中的计量方法同样适用于土壤地理学和土壤资源有关研究中;其次,有关国家已经在土壤多样性的测度方法及其在土壤资源空间表达中作了很多尝试,诸多案例为土壤地理学研究提供了新的角度;最后,新近研究及发展方向主要集中在土壤多样性与土地利用多样性、土地利用类型(耕地、水体、植被等)多样性的关联分析中,已经取得显著进展。这一研究领域日趋活跃,将在土壤地理学及土壤资源相关研究中扮演重要角色并呈现良好的发展前景。 相似文献
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鸡MHC基因多态性与抗病性状的相关性研究进展 总被引：2，自引：0，他引：2
鸡主要组织相容性复合体(MHC)基因具有高度多态性和稳定性,与多种疾病抗性和生产性能紧密相关。本文介绍了国外有关鸡MHC与传染病、寄生虫病和自体免疫病的抗性相关性以及抗性基因的研究进展,并讨论了其在鸡抗病育种中的应用前景。 相似文献
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DNA错配修复(MMR)是DNA损伤修复的一个重要途径,主要司职于DNA合成、遗传重组及损伤过程中新发生的单个及少数碱基的缺失、插入及错配的修复,对维持基因组稳定性和DNA复制保真度至关重要。原核生物的MMR系统主要由MutS、MutH和MutL组成,在高等植物中也鉴定出MutS和MutL的同源物,但未发现MutH。本文介绍了近年来有关植物DNA错配修复及相关基因功能的研究进展,探讨了植物MMR功能缺陷产生的途径及其对植物诱变育种的意义,为进一步利用MMR缺陷突变体进行植物诱发突变与诱变育种研究提供借鉴。 相似文献
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应用RT-PCR及RFLP技术对鸡传染性支气管炎病毒进行诊断与分型的研究进展 总被引：5，自引：0，他引：5
本文概述了近年来国内外应用ＲＴ－ＰＣＲ及ＲＦＬＰ技术对对外开放传染性支气管炎病毒（ＩＢＶ）进行诊断与分型的研究进展。介绍以ＩＢＶ通用引物的ＲＴ－ＰＣＲ进行诊断及其应用、型特异引物的ＲＴ－ＰＣＲ及其应用以及ＲＴ－ＰＣＲ结合ＲＦＬＰ分析技术进行分型的应用,而且还展望了这上结技术在临床诊断及分子流行病学研究上的应用前景。 相似文献
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Soils encompass a huge diversity of organisms which mostly remains to be characterized due to a number of methodological and logistical issues. Nonetheless, remarkable progress has been made in recent years toward developing strategies to characterize and describe soil biodiversity, especially thanks to the development of molecular approaches relying on direct DNA extraction from the soil matrix.Metabarcoding can be applied to DNA from any environment or organism, and is gaining increasing prominence in biodiversity studies. This approach is already commonly used to characterize soil microbial communities and its application is now being extended to other soil organisms, i.e. meso- and macro-fauna.These developments offer unprecedented scientific and operational opportunities in order to better understand soil biodiversity distribution and dynamics, and to propose tools and strategies for biodiversity diagnosis. However, these opportunities also come with challenges that the scientific community must face. Such challenges are related to i) clarification of terminology, (ii) standardisation of methods and further methodological development for additional taxonomic groups, (iii) development of a common database, and (iv) ways to avoid waste of information and data derived from metabarcoding. In order to facilitate common application of metabarcoding in soil biodiversity assessment, we discuss these opportunities and challenges and propose solutions towards a more homogeneous framework. 相似文献
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DNA条形码是应用有足够变异的标准化短基因片段对物种进行快速、准确鉴定的新的生物身份识别系统。2003年,加拿大Guelph大学Hebert等首次正式提出了DNA条形码概念,2004年成立了生物条形码联盟,目前有来自50个国家的两百多个组织成为其成员,2007年5月加拿大Guelph大学组建了世界上第一个DNAbarcoding鉴定中心,2009年1月正式启动“国际生命条形码计划”,中国科学院代表中国与加拿大、美国和欧盟共同为iBOL4个中心节点。线粒体细胞色素C氧化酶基因COI具有引物通用性高和进化速率快等优点,是理想的动物DNA条形码,不过,COI在植物中应用效果较差,因此,核糖体ITS序列和质体rbcL、matK和trnH—psbA等序列也相继被引入植物的DNA条形码研究。虽然DNA条形码研究还处于起步阶段,面临巨大挑战,但是,越来越多的研究表明DNA条形码可以广泛应用于生物的分类和鉴定,是一种简便、高效、准确的物种鉴定技术,已经在动物、植物和微生物等研究中取得了显著成果,是生命科学领域发展最快的学科前沿之一。本文从DNA条形码的开发、应用、国内相关文献研究现状、DNA条形码面临的挑战以及发展前景等进行了综合分析,以期推动我国DNA条形码和分类学研究的发展。 相似文献
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小麦D型细胞质雄性不育系与保持系叶绿体DNA的RAPD分析 总被引：1，自引：1，他引：0
将外源λDNA导入普通小麦品系 81 45 2 7,选出 1稳定的细胞质雄性不育系 ,简称D型不育系。受体 81 45 2 7可以作该不育系的保持系。供体λDNA、受体81 45 2 7、D型不育系及其与鲁麦 1 4号的杂种一代叶绿体DNA的RAPD分析结果显示 ,D型不育系及杂种一代有 1条与供体相同而在受体中不存在的特异带 ,另外有两条特异带在受体和杂种一代中存在 ,而在不育系中消失 ,这两条带可能与育性有关。RAPD分析证明供体DNA片段可以整合插入到受体叶绿体基因组中 ,改变原有的基因表达和调控 ,导致性状变异 相似文献
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J. M. Lynch A. Benedetti H. Insam M. P. Nuti K. Smalla V. Torsvik P. Nannipieri 《Biology and Fertility of Soils》2004,40(6):363-385
This review mainly discusses three related topics: the application of ecological theories to soil, the measurement of microbial diversity by molecular techniques and the impact of transgenic plants and microorganisms on genetic diversity of soil. These topics were debated at the Meeting on Soil Emergency held in Erice (Trapani, Italy) in 2001 for the celebration of the 50th anniversary of the Italian Society of Soil Science. Ecological theories have been developed by studying aboveground ecosystems but have neglected the belowground systems, despite the importance of the latter to the global nutrient cycling and to the presence of life on the Earth. Microbial diversity within the soil is crucial to many functions but it has been difficult in the past to determine the major components. Traditional methods of analysis are useful but with the use of molecular methods it is now possible to detect both culturable and unculturable microbial species. Despite these advances, the link between microbial diversity and soil functions is still a major challenge. Generally studies on genetically modified bacteria have not addressed directly the issue of microbial diversity, being mainly focused on their persistence in the environment, colonization ability in the rhizosphere, and survival. Concerns have been raised that transgenic plants might affect microbial communities in addition to environmental factors related to agricultural practice, season, field site and year. Transgenic plant DNA originating from senescent or degraded plant material or pollen has been shown to persist in soil. Horizontal transfer of transgenic plant DNA to bacteria has been shown by the restoration of deleted antibiotic resistance genes under laboratory in filter transformations, in sterile soil or in planta. However, the transformation frequencies under field conditions are supposed to be very low. It is important to underline that the public debate about antibiotic resistant genes in transgenic plants should not divert the attention from the real causes of bacterial resistance to antibiotics, such as the continued abuse and overuse of antibiotics prescribed by physicians and in animal husbandry. 相似文献
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胞外DNA在土壤中的固定与转化 总被引：3，自引：0，他引：3
DNA is the genetic material of various organisms. Extracellular DNA adsorbed or bound on surface-active particles in soils has been shown to persist for long periods against nucleases degradation and still retain the ability to transform competent cells. This paper reviews some recent advances on the binding and transformation of extracellular DNA in soils,which is fundamental to understanding the nature of the soil, regulating biodiversity, and assessing the risk of releasing genetically engineered microorganisms (GEMs) as well as being helpful for development of the genetic evolutional theory of bacteria. Several influencing factors, such as soil pH, ionic strength, soil surface properties, and characteristics of the DNA polymer, are discussed. To date, the understanding of the type of molecular binding sites and the conformation of adsorbed and bound DNA to soil particles is still in its infancy. 相似文献
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土壤热性质包括土壤热容量、热扩散率和导热率等,是决定土壤热状况的内在因素,与土壤水分状况之间关系密切。热脉冲—时域反射仪方法所用成本低,对土壤扰动小,测试时间短,具有很多优点,因此在测定土壤热性质方面具有很大的潜力。该方法在国外已得到了大量应用,在国内应用却很有限。本文综述了土壤热性质的计算模型及研究现状,重点针对近年来国内外研究土壤热性质的新方法———热脉冲法的理论和技术发展,及其在土壤水和其他物理性质应用方面的进展。该方法在国内相关研究领域里有进一步推广的意义。 相似文献
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N. Teaumroong C. Schwarzer B. Auer K. Haselwandter 《Biology and Fertility of Soils》1997,25(2):159-162
Some soil bacteria are capable of degrading the nitrification inhibitor dicyandiamide (DCD). One of the most efficient isolates
is strain EK1 of Mycobacterium sp. For detecting this and closely related DCD-degrading bacteria in soil we developed a non-radioactive DNA probe. A 1.7-kb
EK1 DNA fragment was selected from a genomic library and labelled with digoxigenin. The probe was highly specific for EK1
and closely related or identical species of soil bacteria. A method for direct detection of DNA from soil was developed. The
sensitivity of this methodology allowed detection of 2×103 EK1 cells g–1 soil.
Received: 15 July 1996 相似文献
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DNA甲基化抑制剂作用机理及其在植物发育生物学研究中的应用 总被引：4，自引：0，他引：4
本文综述了DNA甲基化抑制剂作用机理及其在植物发育生物学研究中的应用。DNA甲基化抑制剂使甲基基团不能转移到腺嘌呤或胞嘧啶,导致DNA甲基化反应受阻,从而使基因组甲基化水平降低。DNA甲基化抑制剂已被用于因DNA甲基化引起的植物表观遗传研究中,同时它可以代替低温促进植物提早开花,并可能在植物性状改良中得到进一步的研究和应用。 相似文献
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Robert H. Gulden David Levy-Booth Jeff R. Powell Kari E. Dunfield K. Peter Pauls Clarence J. Swanton 《Soil biology & biochemistry》2007,39(8):1956-1967
Recent advances in molecular techniques have allowed for the routine examination of nucleic acids in environmental samples. Although current methodologies are very sensitive, accurate target DNA quantification from environmental samples remains challenging. To facilitate high-throughput DNA quantification from environmental samples, we developed a novel DNA quantification method based on a non-linear curve-fitting approach to extract additional information from quantitative PCR amplification curves and used the fitted parameters to develop multiple regression standard equations for target DNA quantification. A 3-parameter sigmoidal function performed superior to a 4-parameter Weibull function for generating the multiple regression standard equations. In a verification experiment, target DNA was quantified in a series of ‘unknown’ samples in three soils using this approach and the results were compared to target DNA values determined using corrected and uncorrected Ct-based (threshold cycle) methods. For each method, the deviations from the expected target DNA content were determined. Results clearly showed that over all DNA concentrations, target DNA content determined by the non-linear curve-fitting method was more accurate and more precise than values predicted by all other methods. Analysis of variance conducted on the predicted DNA contents also revealed fewer statistical artifacts with the non-linear curve fitting method compared to the conventional Ct-based methods. The novel approach described here is accurate, inexpensive, and very amenable for automation and high-throughput applications. 相似文献
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中国节能型日光温室的理论和实践 总被引：9，自引：5，他引：9
扼要介绍了中国节能型日光温室的基本结构、性能、应用和发展概况,重点介绍了该温室建筑结构参数的优化设计,如温室各建筑参数的几何尺寸,采光屋面的倾角和几何形状,墙体结构,后屋面结构及其仰角和投影,外保温覆盖材料和环境调控手段等。同时还介绍了中国节能型日光温室理论研究成果,如建立了日光温室光、热、空气湿度、土壤温度和力学数学模型,并指出这些成果是日光温室结构优化设计的基础。 相似文献