林木遗传图谱构建的研究进展

高密度分子遗传连锁图谱对分析植物遗传变异、标记目标性状、数量性状定位和分子辅助选择改良性状均具重要价值.由于林木具有世代长、高度杂合、遗传负荷大等遗传特性,使其遗传图谱研究不同于其他物种,其遗传连锁图谱的构建相对复杂.目前,一些林木的遗传连锁图谱已经产生.简要综述了林木遗传图谱研究现状和策略,并对构建高质量林木遗传图谱作了展望.     

AFLP分子标记及其应用(综述)

本文简述ＡＦＬＰ分子标记的原理、方法与特点,并综述其在植物遗传多态性及系统发育学研究、基因定位及高密度遗传图谱（或物理图谱）构建和品种鉴定及抗性育种特征性状的分子标记中的应用现状和前景。     

AFLP分子标记及其应用（综述）

本文简述ＡＦＬＰ分子标记的原理、方法与特点,并综述其在植物遗传多态性及系统发育学研究、基因定位及高密度遗传图谱（或物理图谱）构建和品种鉴定及抗性育种特性性状的分子标记中的应用现状和前景。     

大白菜分子遗传图谱构建研究进展

构建大白菜连锁遗传图谱可为其基因组结构分析和比较提供有力工具,可有效应用于数量性状基因定位,基因图位克隆和分子标记辅助育种等研究,因此,构建一张高密度的大白菜遗传图谱具有重要意义。主要从作图群体和分子标记技术两个方面综述大白菜类遗传图谱的研究进展。     

普通菜豆基因组学及抗炭疽病遗传研究进展

普通菜豆是重要的食用豆类之一,在世界各大洲普遍种植。近年来,普通菜豆在遗传图谱构建、新标记开发与利用、抗性基因定位以及比较基因组学等方面取得了很大进展。遗传连锁图谱的构建是基因定位与克隆的基础,是遗传研究中的重要内容;利用分子连锁图谱鉴定、标记和定位抗病基因将在种质改良和分子标记辅助育种方面发挥重要作用。豆科植物比较基因组学的研究成果为菜豆遗传连锁图谱的发展提供了新的思路。本文从普通菜豆遗传连锁图谱的获得、普通菜豆与大豆同线性比较以及抗炭疽病基因定位等方面进行了综述,以期为普通菜豆遗传改良和抗病育种提供参考。 关键词：普通菜豆;遗传连锁图;同线性比较;抗菜豆炭疽病     

中国植物遗传连锁图谱构建研究进展

遗传连锁图谱构建是基因组研究中的重要环节,是基因定位与克隆乃至基因组结构与功能研究的基础上。近十几年来,分子生物学特别是分子标记技术的飞速发展,为构建高饱和的植物遗传连锁图谱和利用分子标记进行辅助育种奠定了基础。综述了我国在植物遗传连锁图谱构建研究方面的进展及发展动态,列举了我国利用DNA分子标记构建的34张植物遗传连锁图谱实例,且讨论了当前我国在该领域研究中存在的问题并提出了解决途径。     

基于SRAP分子标记的冰草遗传连锁图谱构建

构建高密度遗传连锁图谱是冰草抗性、品质、产量等重要性状QTL精细定位及标记辅助育种研究的基础。该试验以四倍体杂交冰草F2群体的202个分离单株及其亲本为材料,利用SRAP分子标记技术和Join Map 4.0作图软件对冰草的遗传连锁图谱进行了构建。结果表明:(1)共筛选出22对多态性好、标记位点清晰稳定的SRAP适宜引物,对冰草杂种F2分离单株的基因组DNA进行PCR扩增,共获得510个SRAP多态性标记位点,其比率占88.2%。(2)偏分离分析表明,偏分离标记比率仅为14.12%,符合遗传作图的要求。(3)成功构建了冰草的SRAP分子标记遗传连锁图谱,该图谱有14个连锁群、510个标记,连锁群间长度范围86.4～179.0cM,覆盖基因组总长度1 912.9cM,标记间平均间距3.75cM,为高密度遗传图谱。     

SSR分子标记在荔枝上的研究进展

SSR作为第二代基于PCR的一种新型DNA分子遗传标记,数量丰富、多态性高、重复性好、分布于整个基因组、特异位点扩增、发生频率高、共显性遗传等,在果树育种中具有极大的应用价值和开发潜力.本文主要简述了SSR标记的原理和特点,并从分子指纹图谱构建、种质资源的遗传多样性分析、核心种质的发掘、品种鉴定、分子标记辅助育种、遗传图谱构建与基因定位等多方面介绍了近年来SSR技术在荔枝上的应用现状及前景.     

生物技术用于黄瓜遗传育种

“十五”期间,生物技术在黄瓜遗传育种上的应用更加广泛,分子标记辅助育种、单倍体育种以及黄瓜基因工程改良取得了重要进展。本文综述了黄瓜基因分子标记、遗传图谱构建、基因定位、基因克隆与表达、品种DNA指纹图谱分析、分子技术鉴定病害、单倍体和三倍体培养、遗传转化体系建立及基因工程改良方面的最新进展,并讨论了存在的问题和前景。     

三色堇与角堇种间遗传连锁图谱构建

该研究以二倍体三色堇和角堇为亲本杂交产生的66株F2代分离群体为作图群体,采用SRAP标记技术进行基因分型,利用JoinMap4.0软件构建了首张三色堇与角堇的种间遗传连锁图谱。结果表明:(1)从256对SRAP引物组合中筛选获得50对多态性好、标记位点清晰且稳定的引物组合。(2)通过对三色堇F2代群体的PCR扩增,共获得118个SRAP多态性标记位点,其中偏分离标记率为24.6%,符合遗传作图需要。(3)成功构建了三色堇和角堇的种间分子遗传连锁图谱,该图谱有15个连锁群,67个SRAP标记,连锁群长度范围1.6~52.2 cM,覆盖基因组总长度327.9 cM,标记间平均图距为4.9 cM。研究结果为三色堇和角堇高密度遗传图谱构建和重要性状的基因定位及分子标记辅助选择育种奠定了基础。     

Rice molecular genetic map using RFLPs and its applications

In the past decade, notable progress has been made in rice molecular genetic mapping using genomic or cDNA clones. A total of over 3000 DNA markers, mainly with RFLPs, have been mapped on the rice genome. In addition, many studies related to tagging of genes of interest, gene isolation by map-based cloning and comparative mapping between cereal genomes have advanced along with the development of a high-density molecular genetic map. Thus rice is considered a pivotal plant among cereal crops and, in addition to Arabidopsis, is a model plant in genome analysis. In this article, the current status of the construction of rice molecular genetic maps and their applications are reviewed.     

水产动物遗传连锁图谱的研究现状及应用展望

综述了近年来遗传连锁图谱在水产生物中的研究现状,包括作图群体、作图方法等,并对连锁图谱的应用前景作了展望,指出其在分子标记辅助育种、基因定位与克隆及比较基因组学等方面的应用潜力。 Abstract:Constructing genetic linkage map is an essential tool to acknowledge genome in aquaculture species.This paper has reviewed the current status of genetic linkage map research,including mapping population,mapping method and molecular markers used to construct linkage map.Linkage map has great potential in marker assisted selection (MAS),gene locating and cloning,and comparative genome mapping.Genetic linkage map with high density and wide coverage of genome will allow cloning the genes which contribute to economically important traits.The ultimate aim of the constructing linkage map is the development of fast-growing,disease-resistant strains of the major aquaculture species.     

70个水稻微卫星标记染色体位置的更正

微卫星标记(SSR)因其操作简单和稳定可靠的特点而成为一种重要的分子标记,被广泛应用于遗传作图和种质鉴定等方面。但其在染色体上位置的正确性将直接影响到基因定位的正确性和后续研究的方向。利用美国国家生物信息技术中心(NCBI)网站的Blast程序,将2740个SSR标记的前后引物序列与水稻粳稻品种日本晴基因组进行比对,共发现70个标记位于另一条染色体,对这70个标记重新锚定的染色体进行了更正。这将有助于今后水稻分子标记遗传连锁图的正确构建。     

SNP分子标记及其在木本植物遗传育种的应用

木本植物因其生命周期长、基因组杂合度高、基因组较大、遗传背景不清晰等特性,制约了其研究进程。随着现代生物技术的发展,DNA分子标记技术在木本植物研究领域的应用越来越多,其中单核苷酸多态性(SNP)作为第三代分子标记技术以其高效、快速、稳定、可靠等诸多优点得到广泛应用。本文简述SNP标记的特点、开发方法、检测方法及其在木本植物遗传多样性和亲缘关系分析、品种鉴定、连锁图谱构建和辅助育种等方面的研究进展,为更好地应用SNP技术开展木本植物研究提供参考。     

An Integrated Genetic and Cytogenetic Map of the Cucumber Genome

The Cucurbitaceae includes important crops such as cucumber, melon, watermelon, squash and pumpkin. However, few genetic and genomic resources are available for plant improvement. Some cucurbit species such as cucumber have a narrow genetic base, which impedes construction of saturated molecular linkage maps. We report herein the development of highly polymorphic simple sequence repeat (SSR) markers originated from whole genome shotgun sequencing and the subsequent construction of a high-density genetic linkage map. This map includes 995 SSRs in seven linkage groups which spans in total 573 cM, and defines ∼680 recombination breakpoints with an average of 0.58 cM between two markers. These linkage groups were then assigned to seven corresponding chromosomes using fluorescent in situ hybridization (FISH). FISH assays also revealed a chromosomal inversion between Cucumis subspecies [C. sativus var. sativus L. and var. hardwickii (R.) Alef], which resulted in marker clustering on the genetic map. A quarter of the mapped markers showed relatively high polymorphism levels among 11 inbred lines of cucumber. Among the 995 markers, 49%, 26% and 22% were conserved in melon, watermelon and pumpkin, respectively. This map will facilitate whole genome sequencing, positional cloning, and molecular breeding in cucumber, and enable the integration of knowledge of gene and trait in cucurbits.     

Construction of a high-density SNP genetic map in flue-cured tobacco based on SLAF-seq

Tobacco (Nicotiana tabacum L., 2n = 48) is an important agronomic crop and model plant. Flue-cured tobacco is the most important type and accounts for approximately 80 % of tobacco production worldwide. The low genetic diversity of flue-cured tobacco impedes the construction of a high-density genetic linkage map using simple sequence repeat (SSR) markers and warrants the exploitation of single nucleotide polymorphic (SNP) markers from genomic regions. In this article, initially using specific locus-amplified fragment sequencing, we discovered 10,891 SNPs that were subsequently used as molecular markers for genetic map construction. Combined with SSR markers, a final high-density genetic map was generated containing 4215 SNPs and 194 SSRs distributed on 24 linkage groups (LGs). The genetic map was 2662.43 cM in length, with an average distance of 0.60 cM between adjacent markers. Furthermore, by mapping the SNP markers to the ancestral genomes of Nicotiana tomentosiformis and Nicotiana sylvestris, a large number of genome rearrangements were identified as occurring after the polyploidization event. Finally, using this novel integrated map and mapping population, two major quantitative trait loci (QTLs) were identified for flue-curing and mapped to the LG6 of tobacco. This is the first report of SNP markers and a SNP-based linkage map being developed in tobacco. The high-density genetic map and QTLs related to tobacco curing will support gene/QTL fine mapping, genome sequence assembly and molecular breeding in tobacco.     

DNA markers in plant improvement: an overview

The progress made in DNA marker technology has been tremendous and exciting. DNA markers have provided valuable tools in various analyses ranging from phylogenetic analysis to the positional cloning of genes. The development of high-density molecular maps which has been facilitated by PCR-based markers, have made the mapping and tagging of almost any trait possible. Marker-assisted selection has the potential to deploy favorable gene combinations for disease control. Comparative studies between incompatible species using these markers has resulted in synteny maps which are useful not only in predicting genome organization and evolution but also have practical application in plant breeding. DNA marker technology has found application in fingerprinting genotypes, in determining seed purity, in systematic sampling of germplasm, and in phylogenetic analysis. This review discusses the use of this technology for the genetic improvement of plants.     

A high-density intervarietal map of the wheat genome enriched with markers derived from expressed sequence tags

Bread wheat (Triticum aestivum L.) is a hexaploid species with a large and complex genome. A reference genetic marker map, namely the International Triticeae Mapping Initiative (ITMI) map, has been constructed with the recombinant inbred line population derived from a cross involving a synthetic line. But it is not sufficient for a full understanding of the wheat genome under artificial selection without comparing it with intervarietal maps. Using an intervarietal mapping population derived by crossing Nanda2419 and Wangshuibai, we constructed a high-density genetic map of wheat. The total map length was 4,223.1 cM, comprising 887 loci, 345 of which were detected by markers derived from expressed sequence tags (ESTs). Two-thirds of the high marker density blocks were present in interstitial and telomeric regions. The map covered, mostly with the EST-derived markers, approximately 158 cM of telomeric regions absent in the ITMI map. The regions of low marker density were largely conserved among cultivars and between homoeologous subgenomes. The loci showing skewed segregation displayed a clustered distribution along chromosomes and some of the segregation distortion regions (SDR) are conserved in different mapping populations. This map enriched with EST-derived markers is important for structure and function analysis of wheat genome as well as in wheat gene mapping, cloning, and breeding programs.