分子标记在植物学中的应用及前景

1　引言随着近年来分子生物学的发展,遗传标记的种类已越来越多,不只局限于传统的形态标记,分子标记尤其显示出独特的优越性,并被广泛地应用于植物学研究的各个领域。那么什么叫标记呢?King和Stansfield〔1〕将其定义为代表一个位于染色体上已知位点的基因或一种清晰的表型性状。总的来说,分子标记目前主要应用于两方面:一是作为基因,尤其是一些重要农艺性状基因如抗虫、抗病基因或数量性状基因的检测尺度,要做到这点,首先必须确定与目的基因紧密连锁的分子标记;二是作为种群分析、种质资源分析及遗传育种的研究依据。2　分子标记的种类及…     

分子标记在家畜遗传多样性研究中的应用

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。     

分子标记及其在核桃遗传多样性研究中的应用

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。     

分子标记在啤酒花种质资源研究中的应用

该论文利用分子生物学中常用的DNA分子标记对世界各地现存的野生和栽培的啤酒花种质资源遗传多样性研究的应用进展做一综述。通过查阅和研读20世纪90年代以来发表的各类文献进行归纳总结。发现DNA分子标记相比形态学标记和细胞学标记具有结果准确、稳定的特点,常用的分子标记技术有RAPD、RFLP、ISSR、SSR、AFLP、EST等;研究发现北美洲的啤酒花遗传多样性要高于欧洲的啤酒花,基因变异程度也相对较高;野生啤酒花的基因序列具有丰富的基因多样性,可在分子杂交遗传育种中作为一个种质去改善栽培品种的某些不良性状。因此,利用分子标记研究啤酒花的遗传多样性将对啤酒花的优良育种提供理论指导和技术支持,目前较为理想的技术是SSR和AFLP。     

分子标记在猕猴遗传多样性研究中的应用

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。     

DNA分子标记在木耳属真菌中的应用研究进展

介绍了目前已在木耳属真菌中广泛应用的几种DNA分子标记技术(RFLP、RAPD、AFLP、ISSR、SRAP、SCAR、ITS、IGS),以及这些标记在木耳属真菌系统发育、分类研究、种间和种内鉴定、遗传多样性分析等方面的应用,并展望了这些标记技术在木耳属真菌中的应用前景。     

分子标记在百合属植物遗传多样性研究中的应用

介绍分子标记技术及其发展概况,并重点论述几种常见分子标记技术如随机扩增多态性DNA(random amplified polymorphism DNA,RAPD)、简单重复序列间区(inter-simple sequence repeat,ISSR)、扩增片段长度多态性(amplified fragment length polymorphism,AFLP)和内转录间隔区(internal transcribed spacer,ITS)等的基本原理、技术上的优缺点及其在百合属植物遗传多样性研究中的应用现状,同时对分子标记技术在百合属植物遗传多样性研究中的应用前景进行展望.     

DNA分子标记在柑桔中的应用

ＤＮＡ分子标记是最为理想的遗传标记 ,依其多态性检出所用的分子生物学技术 ,大致可分为Ｓｏｕｔｈｅｍ杂交技术为核心的分子标记和ＰＣＲ技术为核心的分子标记。前者的代表性技术有ＲＥＬＰ(ｒｅｓｔｒｉｃｔｉｏｎｆｒａｇｍｅｎｔｌｅｎｇｔｈｐｏｌｙｍｏｒｐｈｉｓｍ)和ＤＮＡ指纹技术 (ＤＮＡｆｉｎｇｅｒｐｒｉｎｔｉｎｇｔｅｃｈｎｉｑｕｅｓ)。后者的代表性技术有ＲＡＰＤ(ｒａｎｄｏｍａｍｐｌｉｆｉｅｄｐｏｌｙｍｏｒｐｈｉｃＤＮＡ)、ＳＣＡＲ(ｓｅｑｕｅｎｃｅｃｈａｒａｃ ｔｅｒｉｓｔｉｃａｍｐｌｉｆｉｅｄｒｅｇｉｏｎ)…     

SRAP标记与形态学标记在西瓜DUS测试中的比较

DUS（特异性、一致性和稳定性）测试是进行新品种申请的必要步骤。本文以28个不同的西瓜品种为研究对象,分别采用21对SRAP引物标记和54个用于DUS测试的形态学标记对其进行遗传多样性分析,其中SRAP引物在不同品种间的多态信息含量（PIC）在52.5%~89.2%之间,平均值为72.0%,计算得到的各材料间相似系数在0.92至0.99之间,而形态学标记统计得到各材料间相关系数在0.50到0.85之间。采用UPGMA法对所有材料进行聚类分析,SRAP分子标记聚类划分成四类,形态学标记将其划分为五类。对两种标记所得的结果进行相关性分析得出两者的相关系数为0.218,表明形态学标记和SRAP标记在这些材料上表现的相关性不是很高,但在品种鉴定和区别上SRAP标记表现出一定的优势,可以作为DUS测试的一种有益补充。     

核基因在鸟类分子系统发育学研究中的应用

核基因作为一种新的遗传标记,近年来被广泛应用于鸟类分子系统发育研究中.核基因与线粒体基因位于不同的遗传载体上,因此被引入到系统发育学研究中为物种树的重建提供独立的证据.常用的外显子标记为重组激活基因1(RAG-1),重组激活基因2(RAG-2),癌基因c-myc,原癌基因c-mos,它们由于缓慢的进化速率而被用于鸟类高级分类阶元的系统学研究中.常用的内含子标记是β纤维蛋白原基因内含子7(β-fibrinogen intron7,β-fibint7),肌红蛋白基因内含子Ⅱ(myoglobin intionⅡ).内含子标记通常与线粒体序列联合使用,形成具有互补系统发育信号的数据集,应用于各种分类阶元的系统学研究中.     

EST及其应用

随着HGP（HumanGenomeProject）的实施,人类基因组测序进展顺利,并有望于2003年提前完成。后基因组计划的重点之一在于基因组表达概况和功能的研究。EST（expressedsequencetags）是一组短的cDNA部分序列,是由大量随机取出的cDNA克隆一次测序得到的组织或细胞基因组的表达序列标签。其在基因组研究中的应用已相当广泛并具有良好的前景。该文就EST的产生、相关数据库和应用情况作一综述。     

Molecular markers for phylogenetic applications derived from comparative plastome analysis of Prunus species

Interspecific and intergeneric relationships of Prunus s.l. are still unclear due to low levels of genetic variation among species, and resulting partially unresolved phylogenetic inferences. Here we sequenced and compared six complete plastomes from two subgenera of Prunus in order to choose molecular markers to increase the amount of genetic variation suitable for inference of Prunus phylogeny. The plastomes range between 157 817 and 158 995 bp in length, and we found different levels of inverted repeat (IR) contraction among the three sampled subgenera of Prunus s.l. Most regions in Prunus plastomes considered individually provide low phylogenetic resolution at the subgenus or species level compared to a tree constructed using all 78 coding regions combined. We compared levels of variation among 206 coding regions and noncoding (intergenic and intron) plastid regions and inferred phylogenies from each region considered individually. We then chose using two regions together for future studies of relationships in Prunus, ycf1 and trnT-L, that display high to moderate levels of variation among coding and intergenic regions, respectively, and that individually permit inference of resolved species-level trees in Prunus with moderate to strong branch support. Considered together, these two regions allow inference of the same topology of Prunus inferred using all coding plastid regions combined, with comparable levels of tree support to the full plastome set. These two loci should therefore be useful as a plastid phylogenetic marker set for further inference of relationships within Prunus s.l.     

EST derived SSR markers for comparative mapping in wheat and rice

Structural and functional relationships between the genomes of hexaploid wheat (Triticum aestivum L.) (2n=6x=42) and rice (Oryza sativa L.) (2n=2x=24) were evaluated using linkage maps supplemented with simple sequence repeat (SSR) loci obtained from publicly available expressed sequence tags (ESTs). EST-SSR markers were developed using two main strategies to design primers for each gene: (1) primer design for multiple species based on supercluster analysis, and (2) species-specific primer design. Amplification was more consistent using the species-specific primer design for each gene. Forty-four percent of the primers designed specifically for wheat sequences were successful in amplifying DNA from both species. Existing genetic linkage maps were enhanced for the wheat and rice genomes using orthologous loci amplified with 58 EST-SSR markers obtained from both wheat and rice ESTs. The PCR-based anchor loci identified by these EST-SSR markers support previous patterns of conservation between wheat and rice genomes; however, there was a high frequency of interrupted colinearity. In addition, multiple loci amplified by these primers made the comparative analysis more difficult. Enhanced comparative maps of wheat and rice provide a useful tool for interpreting and transferring molecular, genetic, and breeding information between these two important species. These EST-SSR markers are particularly useful for constructing comparative framework maps for different species, because they amplify closely related genes to provide anchor points across species.Communicated by R. Hagemann     

Microsatellite markers for Vaccinium from EST and genomic libraries

We present 30 microsatellite loci isolated from expressed sequence tag (EST) and genomic libraries in Vaccinium corymbosum L. Allele number per locus in 11 tetraploid and one diploid V. corymbosum accessions ranged from two to 15 (mean = 8.16) in 24 single‐locus simple sequence repeats (SSRs). Cross‐species amplification in a panel of 12 species representing nine sections ranged from 30 to 100% (mean = 83%).     

基于差减cDNA文库EST信息的月季花香突变体SSR标记的开发

在前期月季花香突变体差减文库EST序列信息的工作基础上, 文章开发出新的与花香相关的SSR标记。从正反向差减文库391条EST中检索到10条含有10个SSR的序列, SSR的检出率为2.6%, EST-SSR的重复基元共搜索到10种。利用部分EST-SSRs序列设计了6对SSR引物, 以花香突变体‘往日情怀’及其野生型‘金银岛’DNA为模板, 对引物进行筛选, 5对引物有扩增条带, 其中3对引物有特异性扩增条带。同时利用这些可扩增的引物对典型芳香和无香两组月季栽培品种进行多态性检测, 发现这5对引物均显示多态性。表明所建立的SSR标记是一种可行而有效的方法。     

Mapping microsatellite markers identified in porcine EST sequences

A sequence search of swine expressed sequence tags (EST) data in GenBank identified over 100 sequence files which contained a microsatellite repeat or simple sequence repeat (SSR). Most of these repeat motifs were dinucleotide (CA/GT) repeats; however, a number of tri-, tetra-, penta- and hexa-nucleotide repeats were also detected. An initial assessment of six dinucleotide and 14 higher-order repeat markers indicated that only dinucleotide markers yielded a sufficient number of informative markers (100% vs. 14% for dinucleotide and higher order repeats, respectively). Primers were designed for an additional 50 di- and one tri-nucleotide SSRs. Overall, 42 markers were polymorphic in the US Meat Animal Research Center (MARC) reference population, 17 markers were uninformative and 12 primer pairs failed to satisfactorily amplify genomic DNA. A comparison of di-nucleotide repeat vs. markers with repeat motifs of three to six bases demonstrated that 72% of dinucleotide markers were informative relative to only 7% of other repeat motifs. The difference was the result of a much higher percentage of monomorphic markers in the three to six base repeat motif markers than in the dinucleotide markers (64% vs. 14%). Either higher order repeat motifs are less polymorphic in the porcine genome or our selection criteria for repeat length of more than 17 contiguous bases was too low. The mapped microsatellite markers add to the porcine genetic map and provide valuable links between the porcine and human genome.     

内蒙古菜蝽属4个种昆虫酯酶同工酶的比较研究

应用聚丙烯酰胺凝胶垂直板型电泳技术,对内蒙古地区菜蝽属EurydemaLaporte横纹菜蝽E .gebleriKolenati、新疆菜蝽E .maracandicumOshanin、巴楚菜蝽E .wilkinsiDistant、菜蝽E .dominulus(Scopoli)4个种的酯酶(EST)同工酶作了比较研究。结果表明,菜蝽属4个种的EST同工酶谱带清晰、多态性强、稳定性好,且显示出各自种的特征酶谱,可作为菜蝽属昆虫系统分类学研究的重要分类特征。聚类分析结果进一步证明,内蒙古地区菜蝽属昆虫包含了4个独立的种。聚类图也清晰直观地反映了4种菜蝽之间的系统发育关系,即(((横纹菜蝽,巴楚菜蝽)新疆菜蝽)菜蝽)。