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1.
分子标记技术在蕨类植物遗传多样性研究中的应用   总被引:1,自引:0,他引:1  
简要介绍了蕨类植物的生态类型和生殖方式;回顾了近年来分子标记技术在蕨类植物遗传多样性研究中的应用,主要包括种间亲缘关系和分类学的研究、遗传变异和遗传结构的研究,以及系统发育地理学方面的研究.最后,对蕨类植物遗传多样性研究中存在的一些问题进行了讨论和展望.  相似文献   

2.
武耀廷  张天真  殷剑美 《遗传学报》2001,28(11):1040-1050
利用RAPD,ISSR和SSR3种分子标记方法和2年田间实验对国内外36个陆地棉栽培品种的遗传多样性进行了研究,以3种分子标记在36个品种之间扩增的282条多态性位点所赋值的0,1数据,采用Nei和Li的方法,计算的品种成对相似系数从0.5745到0.9291,其品种平均数从0.6547到0.7524,又以2年品种表现的性状平均数经正态标准化后,采用欧氏距离计算了成对品种的遗传距离。分别以相似系数和传距离矩阵,采用类平均法进行聚类分析,其聚类结果把供试品种大致分为国外品种,新疆品种,早熟类型品种和我国的中熟棉品种等几个类群,类内进一步分组表明,分子标记确定的传关系基本上与品种系谱的种质系统一致,但并不能按系谱或种植生态区域简单地归属,尽管分子标记数据计算的相似系数矩阵和表现型计算的遗传距离矩阵存在极显著的相关关系(r=-0.335),但以遗传距离进行聚类分析的类内分组的组间特征不明显,分子标记是检测类内品种间遗传差异的有效方法,研究结果为棉花育种亲本选配提供了理论依据。  相似文献   

3.
分子标记在家畜遗传多样性研究中的应用   总被引:1,自引:0,他引:1  
家畜遗传多样性是生物多样性的重要组成部分,与人类未来的生存与发展密切相关。中国拥有丰富的地方家畜品种资源,但由于保种不当和盲目引进外来品种进行杂交、资金缺乏等原因,许多品种已濒临灭绝。如何保存利用好我国优良的家畜遗传资源已成为越来越严峻的问题。随着生物学技术的不断发展与完善,许多分子标记技术已经应用于畜禽遗传资源的研究。简要介绍了在家畜遗传多样性研究中应用最广的几种分子标记及其特性,讨论了在家畜遗传多样性的研究中如何选用适当的分子标记。  相似文献   

4.
采用SSR分子标记分析延胡索的遗传多样性,筛选出多态性高、稳定性好的12对引物,对19个居群360份延胡索样品进行了群体遗传分析。结果表明:(1)12对SSR引物共扩增出多态性位点227个,检测到4~9个等位基因,平均等位基因数目为5.25个,表现出丰富的多态性;延胡索居群具有较高的遗传多样性(Na=5.25,I=1.192 6,H=0.387 9),物种间遗传分化程度高(Fst=0.388 3),基因流较弱(Nm=0.393 8)。(2)UPGMA聚类分析和贝叶斯距离分析结果表明,19个居群明显聚为4大支;Mantle Test结果(r=0.326,P=0.01)表明,地理位置相近的种群亲缘关系更近。研究认为,延胡索的遗传结构是该物种自交为主的繁育系统、克隆生长、地理隔离以及居群间有限的基因流共同作用的结果,故对该物种的保护应以就地保护为主。  相似文献   

5.
分子标记在猕猴遗传多样性研究中的应用   总被引:4,自引:2,他引:4  
分子标记目前已成为研究遗传多样性的主要工具,为此,简要综述了几种常用的分子标记(RFLPs、RAPD、mtDNA、微卫星DNA、SNPs)的检测方法及其在猕猴种群遗传多样性研究中的应用,为国内猕猴遗传多样性的研究提供参考。  相似文献   

6.
生物分子的多样性   总被引:1,自引:0,他引:1  
王克夷 《生命的化学》1999,19(3):145-147
大千世界无奇不有,这正是客观世界绚丽多姿的写照。各种生物都有其存在的价值和合理性。然而,或是由于对自然界的认识不足,或是为了某种目的,人们总是在改变,甚至有意或无意地破坏我们赖以生存的世界。为此,长期以来一些生物学家一再呼吁重视生物圈和濒危物种的保护...  相似文献   

7.
核桃是我国重要的坚果和木本油料树种之一,具有重要的学术研究和经济价值。现代分子标记技术的迅速发展为核桃的种质鉴定、遗传育种、遗传多样性分析、亲缘鉴定等提供了崭新途径。本文主要介绍RFLP、RAPD、AFLP及SSR等几种分子标记技术的主要原理、特点以及在核桃遗传多样性方面的研究进展,分析了分子标记在核桃遗传多样性研究中的主要问题,并对其发展提出了展望。  相似文献   

8.
牦牛分子遗传多样性研究进展   总被引:5,自引:0,他引:5  
遗传多样性研究可有效地揭示牦牛的遗传变异, 是牦牛群体遗传学研究的主要内容之一。自20世纪70年代以来, 人们已对牦牛的体形外貌特征、染色体核型(带型)、生理生化特性和DNA序列变异等进行了较为深入地研究。随着分子遗传学和DNA测序技术的迅猛发展, 近年来的研究主要集中在牦牛的分子遗传多样性。文章对近15年来牦牛mtDNA和核基因组分子标记及侯选基因多样性的研究现状进行了综述, 对前景进行展望, 以期为牦牛群体基因组学等研究提供依据。  相似文献   

9.
实验兔是重要的实验动物之一,在医药领域发挥重要作用。各种分子遗传标记的出现为实验兔系统发育、种群遗传结构分析以及质量控制等各个领域提供了更为简便、可靠的研究手段。但目前,国内实验兔遗传质量不稳定,遗传背景不明确,严重制约着实验兔的应用。本文对各种分子标记在兔遗传多样性中的应用进行综述,以为实验兔遗传检测方法的建立提供帮助。  相似文献   

10.
DNA分子标记技术及其在植物遗传多样性研究中的应用   总被引:24,自引:0,他引:24  
本文阐述了DNA限制性片段长度多态性、DNA指纹图谱、单位点小卫星、单位点微卫星及随机扩增多态DNA等主要的DNA遗传标记技术的基本原理和方法.综述了不同DNA标记的优缺点及其在植物遗传多样性研究中的应用前景.  相似文献   

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12.
禾本科作物与人类密切相关,对其分子水平上的研究具有重要的理论和实践意义。EST技术的产生和不断完善为禾本科植物的研究带来了新的思路,迅速推动禾本科植物研究工作的进行。本文综述了EST技术在禾本科植物研究中的应用,包括EST分子标记、构建遗传学图谱、比较基因组学、发现与克隆新基因、基因表达研究以及DNA芯片技术等,并对EST在禾本科植物研究中存在的问题及应用前景进行了分析。  相似文献   

13.
DNA repeats are causes and consequences of genome plasticity. Repeats are created by intrachromosomal recombination or horizontal transfer. They are targeted by recombination processes leading to amplifications, deletions and rearrangements of genetic material. The identification and analysis of repeats in nearly 700 genomes of bacteria and archaea is facilitated by the existence of sequence data and adequate bioinformatic tools. These have revealed the immense diversity of repeats in genomes, from those created by selfish elements to the ones used for protection against selfish elements, from those arising from transient gene amplifications to the ones leading to stable duplications. Experimental works have shown that some repeats do not carry any adaptive value, while others allow functional diversification and increased expression. All repeats carry some potential to disorganize and destabilize genomes. Because recombination and selection for repeats vary between genomes, the number and types of repeats are also quite diverse and in line with ecological variables, such as host-dependent associations or population sizes, and with genetic variables, such as the recombination machinery. From an evolutionary point of view, repeats represent both opportunities and problems. We describe how repeats are created and how they can be found in genomes. We then focus on the functional and genomic consequences of repeats that dictate their fate.  相似文献   

14.
结核分枝杆菌基因组学与基因组进化   总被引:1,自引:0,他引:1       下载免费PDF全文
在后基因组时代,特别是在新的测序理论和设备大发展的背景下,一些重大传染性致病微生物基因组序列正在被逐一测定,并且随后的基因功能注释,蛋白质三维结构重建等工作也正在开展,以期对致病微生物的生物学特性、诊断策略和治疗方法等有突破性的认识.作为对人类健康一直存在严重威胁的结核分枝杆菌,其基因组在进化中所发生的各种遗传事件对其生物学性质、致病能力和抗药性等各方面有重要作用.本文旨在阐述结核分枝杆菌的起源及其基因组特征,论述其基因组进化的研究进展.  相似文献   

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16.
Summary This report reviews the contributions to the improvement of sorghum (Sorghum bicolor (L.) Moench) through traditional approaches with emphasis on the application of biotechnological methods. Strategies include breeding for higher yield, improved grain quality, and biotic and abiotic stress tolerance. Hybrid development and polyploidy breeding are also discussed. Plant breeders, working in concert with biotechnologists, have developed new powerful tools for plant genetic manipulation and genotype evaluation that will significantly improve the efficiency of plant breeding. Improving sorghum through biotechnology is the latest in a long series of technologies that have been applied to this crop. Five basic tools of technology have been developed for sorghum improvement: (1) in vitro protocols for efficient plant regeneration; (2) molecular markers; (3) gene identification and cloning; (4) genetic engineering and gene transfer technology to integrate desirable traits into the sorghum genome; and (5) genomics and germplasm databases. Reports on studies involving the problems, progress, and prospects for utilizing the biotechnological methods for sorghum improvement are discussed.  相似文献   

17.
    
The evolutionary origin of complex organs challenges empirical study because most organs evolved hundreds of millions of years ago. The placenta of live-bearing fish in the family Poeciliidae represents a unique opportunity to study the evolutionary origin of complex organs, because in this family a placenta evolved at least nine times independently. It is currently unknown whether this repeated evolution is accompanied by similar, repeated, genomic changes in placental species. Here, we compare whole genomes of 26 poeciliid species representing six out of nine independent origins of placentation. Evolutionary rate analysis revealed that the evolution of the placenta coincides with convergent shifts in the evolutionary rate of 78 protein-coding genes, mainly observed in transporter- and vesicle-located genes. Furthermore, differences in sequence conservation showed that placental evolution coincided with similar changes in 76 noncoding regulatory elements, occurring primarily around genes that regulate development. The unexpected high occurrence of GATA simple repeats in the regulatory elements suggests an important function for GATA repeats in developmental gene regulation. The distinction in molecular evolution observed, with protein-coding parallel changes more often found in metabolic and structural pathways, compared with regulatory change more frequently found in developmental pathways, offers a compelling model for complex trait evolution in general: changing the regulation of otherwise highly conserved developmental genes may allow for the evolution of complex traits.  相似文献   

18.
Previous molecular phylogeny algorithms mainly rely onmulti-sequence alignments of cautiously selected characteristic sequences,thus not directly appropriate for whole genome phylogeny where eventssuch as rearrangements make full-length alignments impossible. Weintroduce here the concept of Complete Information Set (CIS) and itsmeasurement implementation as evolution distance without reference tosizes. As method proof-test, the 16s rRNA sequences of 22 completelysequenced Bacteria and Archaea species are used to reconstruct aphylogenetic tree, which is generally consistent with the commonlyaccepted one. Based on whole genome, our further efforts yield a highlyrobust whole genome phylogenetic tree, supporting separate monophyleticcluster of species with similar phenotype as well as the early evolution ofthermophilic Bacteria and late diverging of Eukarya. The purpose of thiswork is not to contradict or confirm previous phylogeny standards butrather to bring a brand-new algorithm and tool to the phylogeny researchcommunity. The software to estimate the sequence distance and materialsused in this study are available upon request to corresponding author.  相似文献   

19.
    
The domestication of the wine yeast Saccharomyces cerevisiae is thought to be contemporary with the development and expansion of viticulture along the Mediterranean basin. Until now, the unavailability of wild lineages prevented the identification of the closest wild relatives of wine yeasts. Here, we enlarge the collection of natural lineages and employ whole‐genome data of oak‐associated wild isolates to study a balanced number of anthropic and natural S. cerevisiae strains. We identified industrial variants and new geographically delimited populations, including a novel Mediterranean oak population. This population is the closest relative of the wine lineage as shown by a weak population structure and further supported by genomewide population analyses. A coalescent model considering partial isolation with asymmetrical migration, mostly from the wild group into the Wine group, and population growth, was found to be best supported by the data. Importantly, divergence time estimates between the two populations agree with historical evidence for winemaking. We show that three horizontally transmitted regions, previously described to contain genes relevant to wine fermentation, are present in the Wine group but not in the Mediterranean oak group. This represents a major discontinuity between the two populations and is likely to denote a domestication fingerprint in wine yeasts. Taken together, these results indicate that Mediterranean oaks harbour the wild genetic stock of domesticated wine yeasts.  相似文献   

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