与玉米奥帕克——6位点连锁的RFLP标记

以具有奥帕克－－６基因遗传背影的、已知基因型的和不透明籽粒的四类玉米材料作试材,用玉米第８染色体ＲＦＬＰ连锁图上的部分标记作探针,通过多态性、连锁性和实用性的实验分析,筛选出与奥帕克－６位点连锁的３个ＲＦＬＰ标记,即ＢＮＬ９．４４,ＢＮＬ９．０８,ＢＮＬ７．０８。其中,以ＢＮＬ９．４的连锁性及实性较好,以它作探针与用ＨｉｎｄⅢ限制性内切酶酶切的玉米基因组ＤＮＡ片段杂交,所得２．０ｋｂ的ＤＮＡ片段与     

水稻野败不育系与保持系线粒体DNA限制酶酶切图谱分析

采用限制酶酶切片段长度多态性（ＲＦＬＰ）分析广泛比较了水稻野败不育系及其籼型保持系线粒体ＤＮＡ酶切图谱。野败不育系与籼型保持系线粒体ＤＮＡ在组成上存在十分明显的差异。根据具有相同迁移位置与大小的片段比例判断，这２种不同细胞质线粒体ＤＮＡ顺序同源性约为３０％。分子杂交结果显示，编码功能蛋白的基因及其邻近顺序存在在相当程度的保守性。本文并对线粒体ＤＮＡ的组成变异与细胞质雄性不育的关系进行了分析与讨论。     

扩增片段长度多态技术及其在遗传分析中的应用

扩增片段长度多态性（ＡＦＬＰ）是建立在ＰＣＲ和ＲＦＬＰ技术基础上的一项新的ＤＮＡ指纹技术，可广泛应用于种系鉴定，遗传多样性检测，群体分类研究，构建遗传图谱，标定目的基因等方面。本文结合ＡＦＬＰ的最新发展，对该项技术的原理特点、分析流程、优越性进行了概述，提出了ＡＦＬＰ分析中应注意的问题，并探讨了该技术的应用前景。     

利用RFLP研究作物亲缘关系的计算机程序设计

一、引言DNA限制性片段长度多态性(Restriction Fragment Length Polymorphism简称RFLP)是近年来分子遗传学研究中发展起来的一种新技术。其技术要点是:DNA经限制性内切酶酶切后,产生不同长度的片段;经琼脂糖电泳分离这些不同的片段,印迹转移至硝酸纤维素滤膜上;然后用一放射性同位素标记的特定DNA克隆(探针)杂     

36个水稻骨干系的分子聚类及其遗传育种学意义 Ⅰ分子标记多态性与杂交亲和性关系的研究

对３６个水稻骨干系进行了ＲＦＬＰ（限制性内切酶长度多态性）分析，并对这些水稻材料的１６２个杂交组合育性进行了分组分类研究。杂种育性的遗传基础研究表明，亚种内杂交组合育性显著高于亚种间杂交组合育性。亚种间杂交不育性是由籼粳两个亚种间深刻的遗传分化引起的。广亲和性品种为亲本之一的杂交组合多数（７１．７％）具有正常的育性，ＲＦＬＰ分析表明，这些杂交组合的遗传基础特殊，其遗传距离大于典型的亚种内组合距离，而小于典型的亚种间遗传距离。广亲和性水稻种质的创建、改造和利用潜力是大的，广亲和基因作用及其与杂种优势表现有关的若干遗传育种学问题要协同一并去解决。     

一对粳稻细胞质雄性不育系与恢复系的DNA限制性片段长度的多态性分析

通过对粳稻细胞质雄性不育系秀岭 A 和 C8411的染色体限制性片段长度的多态性分析,定量地评估了它们的 F_1杂种基因组的杂合性。在评估时,总共检测了12对染色体上的122个位点,使用9种不同的限制性内切酶,结果发现,在26%的位点中有等位的差异,而且呈现多态性的位点不是随机或均匀地分布在不同的染色体上的。根据揭示多态性的限     

组培品种黑珍米与供体的形态差异及其RFLP分析

由水稻组织培养后代选育的品种黑珍米与亲本Ｂａｓｍａｔｉ ３７０相比，其形态性状，如株高、每穗总数粒，穗长，单株有效穗数，千粒重和生育期等发生了显著变化；并且使原来的白稃尖和白谷壳变成了紫稃尖和紫色谷壳。应用分布于１２条水稻染色体的１２１个ＤＮＡ探针分析黑珍米与其亲本的ＲＦＬＰ，结果表明：有２４．８％的探针检测到了多态性，分布于１０条染色体。结合４种限制性内切酶（ＥｃｏＲＩ，ＢａｍＨＩ，ＨｉｎｄⅢ和     

中国水稻白叶枯病菌系染色体DNA的RFLP谱型的初析

用２个ＤＮＡ探针ｐＪＥＬ１０１和ｐＢＡＳａｖｒＸａ１０对７８个水稻白叶枯病菌系进行ＲＦＬＰ分型，以分析其群体结构和遗传多样性。分别鉴定出１６种ＲＦＬＰ标记带的谱型。以彼此的带位相似率达８５％为界，可分为簇。参试菌系的群体遗传多样性为０．７７（用ｐＪＥＬ１０１），和０．８３ＲＦＬＰ谱型分析表明：我国多数病原型为杂合组群。白叶枯病菌系的分子表现型的变异，远远大于致病型，两个探针都能有效分析我国菌系的群     

利用RAPD标记鉴定大豆种质

本研究以５７个中国大豆祖先吕系及育成品种和１８个美国大豆祖先品系为ＤＮＡ样品来源，通过随机引物ＰＣＲ扩增基因组ＤＮＡ的多态性，探索利用ＲＡＰＤ标记鉴定和相关种质的可能性。研究结果表明，５０个１０摩尔随机引物共扩增可分辩产物２４６个，其中８２．４％的随机引物可产生多态性产物，所扩增产物的５４．４％至少在两个基因毒草境存在差异。上ＰＣＲ扩增产物分别以１和０记录存在与否。扩增产物间的成对比较可产生非相似     

桃果实有毛/无毛、白肉/黄肉性状的RAPD分子标记

以桃品种京玉和美味的正反交后代６９株为试材,采用ＲＡＰＤ指纹分析技术,获得了控制桃果实性状有毛／无毛、白肉／黄肉这２个基因的ＲＡＰＤ分子连锁标记,其中多态性扩增ＤＮＡ片段ＯＰＰ２０－２２００与果实有毛／无毛基因的连锁遗传距离为５．０ｃＭ,多态性扩增ＤＮＡ片段ＯＰＵ０３－８５０与果实白肉／黄肉基因的连锁距离为９．６ｃＭ。     

DNA分子标记在野生大豆遗传多样性研究中的应用进展

为了研究陕西省不同居群野生大豆的遗传多样性,本研究归纳了几种常见DNA分子标记技术（RFLP、RAPD、AFLP、SSR、ISSR、SNP）的原理及特点,综述了不同DNA分子标记在野生大豆遗传多样性研究中的应用现状。分析了不同DNA分子标记在野生大豆遗传多样性研究上的优缺点,提出了SSR标记的发展前景,以及在研究野生大豆遗传多样性上存在的优势。     

Comparisons of RFLP and PCR-based markers to detect polymorphism between wheat cultivars

Previously chromosome 3A of wheat (Triticum aestivum L.) was reported to carry genes influencing yield, yield components, plant height, and anthesis date. The objective of current study was to survey various molecular marker systems for their ability to detect polymorphism between wheat cultivars Cheyenne(CNN) and Wichita (WI), particularly for chromosome3A. Seventy-seven `sequence tagged site' (STS), 10simple sequence repeat (SSR), 40 randomly amplified polymorphic DNA (RAPD) markers, and 52 restriction fragment length polymorphism (RFLP) probes for wheat homoeologous group 3 chromosomes, were investigated. Three (3.9%) STS-PCR primer sets amplified polymorphic fragments for the two cultivars, of which one was polymorphic for chromosome 3A. Sixty percent of SSR markers detected polymorphism between CNN and WI of which 50% were polymorphic for chromosome 3A. Twenty percent of RAPD markers detected polymorphism between CNN and WI in general, but none of these detected polymorphism for chromosome 3A. Of the fifty-two RFLP probes, 78.8% detected polymorphism between CNN and WI for group 3 chromosomes with one or more of seven restriction enzymes and 42% of the polymorphic fragements were for chromosome 3A. These high levels of RFLP and SSR polymorphisms between two related wheat cultivars could be used to map and tag genes influencing important agronomic traits. It may also be important to reconsider RFLP as the most suitable marker system at least for anchor maps of closely related wheat cultivars. This revised version was published online in July 2006 with corrections to the Cover Date.     

A comparative analysis of the genetic relationships between rye cultivars using RFLP and RAPD markers

Summary The genetic similarities of eight closely related rye cultivars were estimated using two molecular marking techniques: restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD). Cultivars were evaluated for variation by 11 random cDNA and genomic clones used in combination with four restriction enzymes and 40 decamer primers. A total of 53 polymorphic RFLP fragments and 94 polymorphic RAPD fragments were observed. Based on the presence/absence of fragments, two genetic similarity matrices were calculated which were then used in cluster analysis. Differences between pair of cultivars were observed in RFLP and RAPD dendrograms. RFLP analysis produced estimates of genetic relationships more in accordance with the partially known pedigree of the cultivars than did RAPD analysis. The use of bulk samples of DNA in these analyses affected the sensitivity of RAPD assays more strongly. Dendrograms which took into account all fragments produced, either by RFLP or RAPD, reflected better the relationships between cultivars than did dendrograms based on only one type of marker. This reflects the importance of the number of markers used in determining the genetic relationships between genotypes.     

Genetic diversity of barley cultivars grown in Spain, estimated by RFLP, similarity and coancestry coefficients

This study was conducted with the objective of characterizing the genetic variation among a representative set of 37 barley cultivars currently grown in Spain, using restriction fragment length polymorphism (RFLP) markers. Thirty-two RFLP probes, in combination with three restriction enzymes, were used to analyse polymorphism at the molecular level. Genetic distances (GD), based on RFLP band patterns, and coancestry coefficients (f), based on pedigree records, were calculated. Of the 95 clone-enzyme combinations analysed, 71 (74.7%) were polymorphic, representing 246 RFLP patterns. A cluster analysis of GD split the sample into five distinct germplasm groups that were consistent with the history of the cultivars (winter European, spring European, CIMMYT-ICARDA materials, the single cultivar ‘Dobla’ and Spanish local materials). The Spanish group was the most distinct one and had unique alleles at markers close to major loci determining phonological adaptation. The probes which best distinguished among groups were also identified. Genetic similarity estimates were moderately consistent with f (for cultivars with complete pedigrees). The implications for integration of diversity studies into breeding programmes are discussed.     

Genetic diversity and population structure of Indian soybean [<Emphasis Type="Italic">Glycine max</Emphasis> (L.) Merr.] revealed by simple sequence repeat markers

Genetic diversity in 90 Indian soybean cultivars was assessed using 45 SSR markers distributed on 20 soybean chromosomes. Forty-five SSR markers generated 232 alleles with an average of five alleles/locus. The observed frequencies of the 232 alleles ranged from 0.01 to 0.94 with an average of 0.19. The polymorphic information content (PIC) value of the SSR markers varied from 0.10 to 0.83 with an average of 0.61 and about 71% markers have a PIC value of >0.5. In this study, 54 rare alleles including 19 genotype specific alleles were also identified. The observed hetrozygosity for SSR markers ranged from 0 to 0.11 with a mean of 0.10. Cluster analysis grouped the 90 soybean cultivars into three major clusters and principal coordinates analysis (PCoA) results were similar to those of the cluster analysis. A combination of eight SSR markers successfully differentiated all 90 soybean cultivars. The population structure analysis distributed the 90 soybean genotypes into two populations with mean alpha (α) value of 0.1873. In AMOVA analysis, proportion of variation within population was high (88%), whereas only 12% occurred among populations. In cluster and structure analyses, most of the genotypes with similar pedigree were grouped together. Soybean cultivars DS228, MACS-13, LSb-1, Hardee, Improved Pelican, and Pusa-24 were the six most genetically distinct cultivars identified. The study reported a moderate genetic diversity in Indian soybean cultivars and findings would be useful to the soybean breeders in selecting genetically distinct parents for a soybean improvement program.     

Development and initial evaluation of diversity array technology for soybean and mungbean

Diversity Array Technology (DArT), a technique for quickly generating large numbers of molecular markers, was established for two legume crops, soybean (Glycine max) and mungbean (Vigna radiata). For each crop, two genomic complexity reduction methods, utilizing PstI/TaqI and PstI/BstNI restriction digests, were selected for DNA clonal library development and for the isolation in each case of 7,680 DArT clones from genomic representations of pooled DNA samples. While the PstI/BstNI method produced more polymorphic clones than PstI/TaqI for the soybean library, there was no significant difference between the two methods for the mungbean library. Polymorphism frequencies in mungbean were around twice those in soybean, reflecting greater diversity in the mungbean samples. Even so, there were still nearly 1,500 unique polymorphic clones identified for soybean. The DArT marker transferability from soybean to mungbean (13.6%) was nearly five times higher than that from mungbean to soybean (3.1%). The percentage of DArT marker transferability between mungbean and several other Vigna species ranged from 3.4 to 20.2%. The genetic similarities among 11 diverse Vigna spp. samples, evaluated using the DArT mungbean library, were consistent with published information on these taxa. The results indicated that for soybean and mungbean, the DArT technique is an effective tool for marker generation in terms of speed and the numbers of markers identified. The transferability of markers between soybean and mungbean indicated that DArT may be useful for comparative genomic studies, while the ability of the mungbean library to discriminate between related Vigna taxa suggested that DArT may also be useful for studies of genetic diversity.     

Tagging the juvenile locus in soybean [Glycine max (L.) Merr.] with molecular markers

Soybean cultivars carrying the `long juvenile trait' show a delayed flowering response under short day conditions. The incorporation of this character into genotypes of agronomic interest may allow a broader range of sowing dates and latitudes for a single cultivar adaptation. The objective of this work was to identify molecular markers linked to the juvenile locus in soybean. Experiments were carried out using two pairs of near isogenic lines(NILs) differing in the presence of the long juvenile trait, and RAPD markers. Four hundred primers were first screened to find polymorphism associated with the trait. Additional differences between NILs were sought by digesting the genomic DNA with five restriction enzymes. Polymorphic fragments detected between NILs were tested for linkage to the juvenile locus in the corresponding F₂ segregating populations. Marker bc357-HaeIII was linked (χ²L = 46.316) to the juvenile locus with an estimated recombination frequency of 0.13 ± 0.03in one of the genetic backgrounds studied. The fragment was cloned, sequenced and converted into a SCAR marker. Moreover,bc357-HaeIII was used as RFLP probe. Both, SCAR and RFLP generated markers linked to the juvenile locus in the two genetic backgrounds analysed. Results presented in this work can be utilised for both, the localisation of the gene associated with the character and for tagging the juvenile trait in soybean breeding programs. This revised version was published online in August 2006 with corrections to the Cover Date.     

用SSR标记提高水稻分子连锁图谱密度

本课题组利用圭630／台湾粳的DH群体，建立了一个水稻RFLP连锁图。该图谱含175个标记，总长1224．6cM，相邻标记间平均距离为7．0cM。但该图标记分布不够均匀，存在较多空白区，且在第4和第8染色体上分别存在一个断点。本研究试图在原有RFLP图谱的基础上，添加一些SSR标记，以使该图谱标记更加密集和均匀，并消除两个断点。共筛选了361对RM引物，获得了183对多态标记，在12条染色体上共整合了57个RM标记，染色体连锁图总长度为1811．2cM，比原图谱增长了47．9％，相邻标记间平均距离为7．8cM，与原图谱相近。不过，两条染色体上的两个断点仍无法消除，暗示这两个断点区域多态性较低或重组率较高。     

利用与大豆灰斑病抗性基因连锁的SSR标记构建品种(系)的分子身份证

以黑龙江省29个大豆育种单位的103份已鉴定大豆灰斑病3个生理小种抗性的大豆品种(系)为材料,选择与大豆灰斑病抗病基因连锁的19个SSR标记检测,获得等位变异数86个,每个标记检测到的等位变异数分布在2~6个之间,平均为4.42个。应用遗传统计软件(genetics statistics 3.0)分析表明, 标记的多样性指数介于0.198~0.751之间,平均多样性指数为0.606。品种(系)特异指数差异较大,介于46.592~481.541之间,平均为87.415。根据标记的等位基因数,使用ID Analysis 1.0软件分析表明,利用与大豆抗灰斑病基因连锁的7个SSR标记(Satt565、Satt547、Satt431、Sct_186、SOYGPATR、Satt244、Sat_151)就能有效区分各品种(系),因此利用这7个标记构建了供试品种(系)的分子身份证。     

Genetic diversity,population structure and key phenotypic traits driving variation within soyabean (Glycine max) collection in Ghana

Soybean [Glycine max (L.) Merrill] is an important oilseed crop worldwide and it has recently become the crop of interest in Ghana. In this study, 142 soybean accessions were genotyped with 34 SSR markers and concurrently evaluated for five quantitative and two qualitative phenotypic traits. Twenty‐nine of the SSR markers were polymorphic with mean allele number of 5.3, polymorphic information content (PIC) of 0.51 and gene diversity of 0.55. Molecular analysis based on unweighted paired group arithmetic mean (UPGMA) clustering and principal coordinate analysis (PCoA) was similar in explaining the extent of diversity within the accessions. Structure analysis placed most of the accessions into two subpopulations with 18 (12.7%) as admixtures. Principal component analysis (PCA) based on phenotypic traits revealed two clusters. Both UPGMA clustering‐based SSR data and PCA from phenotypic data showed similar results. The assembled germplasm is genetically diverse with high variation in flowering and maturity period, and key yield components which could be exploited in developing superior varieties well adapted to Ghana and West Africa.