花生栽培种SSR遗传图谱的构建

花生栽培种品种间分子多态性相对缺乏, 至今未构建出较完整的分子遗传图谱。本研究以粤油13和阜95-5为亲本, 通过杂交构建包含184个F6重组自交系的遗传作图群体。采用652对genomic-SSR引物和392对EST-SSR引物对亲本进行多态性检测, 从中筛选出121对多态性引物, 在亲本中共检测到123个多态性位点。利用作图群体对多态性SSR位点进行遗传连锁分析, 获得包含108个SSR标记(102个genomic-SSR标记和6个EST-SSR标记), 涉及20个连锁群, 总长568 cM, 平均图距为6.45 cM的花生栽培种遗传图谱。与前人构建的花生野生种(A. duranensis × A. stenosperma, AA genome)SSR遗传图谱比较, 初步确定本研究构建的遗传图谱中有11个连锁群与野生种遗传图谱的6个连锁群存在同源关系。     

棉花F_2群体及RIL群体SSR标记偏分离的比较剖析

为了探究棉花群体中SSR分子标记的偏分离现象,以本课题构建的两个陆地棉群体(‘冀棉11’ב中植棉2号’) F_2和(‘常抗棉’בTM-1’) RIL群体为研究材料,利用一万余对SSR引物同时对其双亲进行多态性引物筛选,分别获得133个在F_2亲本间具有多态的SSR标记,119个在RIL亲本间具有多态的SSR标记,以此为基础构建连锁图谱,对进入F_2连锁图谱的114个多态性标记以及进入RIL连锁图谱的78个多态性标记进行偏分离卡方检测,对比分析后发现:RIL群体的标记偏分离率远高于F_2群体,偏分离率分别为60.26%和19.30%。同时,我们对两个图谱中的共有标记及其所在染色体进行了比对分析,认为在染色体D01 (Chr15)和D03 (Chr17)上可能存在导致偏分离的配子基因。本研究为其它连锁图谱的构建及QTL的准确定位提供帮助,并将有助于定位出棉花中导致偏分离的配子体基因。     

一组新的小麦EST-SSR标记开发及其在遗传图谱构建中的应用

为了丰富小麦功能分子标记的数量,为小麦功能基因的定位、比较基因组学、小麦起源和进化等方面的研究奠定基础。从前期利用小麦转录组数据鉴定出的8 389个EST-SSR序列中,随机选取585对引物得分大于95的标记进行分析,以川麦42和川农16杂交后自交获得的重组自交系群体为试验材料,利用新开发出的EST-SSR标记,并结合SSR标记和SRAP标记,构建了一张遗传图谱。结果表明,585对EST-SSR引物中有555对能在亲本川麦42和川农16中扩增出稳定清晰的条带,引物有效性为94.87%。其中有44对EST-SSR引物在川麦42和川农16中表现出明显的、稳定的多态性,多态性率为7.93%。所构建的遗传图谱中含有本次新开发的EST-SSR标记的连锁群共12个,由163个标记组成,包括17个EST-SSR标记,73个SSR标记和73个SRAP标记,覆盖小麦基因组长度1 551.5 cM,相邻标记之间的平均距离为13.11 cM。本研究丰富了小麦功能分子标记的数量,为小麦功能基因的定位、比较基因组学、小麦起源和进化等方面的研究奠定基础。     

大白菜遗传图谱的构建及与染色体关联分析

为构建大白菜遗传图谱,并与国际上公认的白菜参照图谱相关联。以大白菜晚抽薹DH系Y177-12和早抽薹DH系Y195-93为亲本建立的183个DH系为作图群体,利用SRAP、SSR、AFLP、STS、ESTP和CAPS等多种分子标记和形态标记构建大白菜遗传图谱,通过参照图上的锚定标记确定连锁群,并用最新的连锁群命名法进行命名。构建了包含10个连锁群、233个标记位点的分子遗传图谱,其中包括145个SRAP标记、62个SSR标记、12个AFLP标记、6个STS标记、4个ESTP标记、3个形态标记和1个CAPS标记。图谱总长度1 036 cM,标记间的平均图距为4.4cM。通过其中的38个SSR,4个ESTP和2个STS标记将各个连锁群与国际上认可A1-A10的参照连锁群相关联。该图谱的构建将为不同图谱的比较与整合及重要农艺性状的基因定位奠定基础。     

基于EST-SSR的木薯分子标记遗传连锁图谱的构建

此实验以木薯推广品种‘KU50’为母本,‘SC124’为父本通过杂交得到包含240个单株的F1分离群体,利用300对EST-SSR引物,20对SSR和20对SRAP引物组合对亲本和部分群体株系进行多态性分子标记筛选,共获得具有多态性的引物110对。在此基础上,利用这110对多态性引物对该F1群体进行分子标记的多态性分析,共获得269个多态性标记。利用JoinMap 3.0软件对这269个多态性标记进行分组和遗传图谱构建,最后获得了一张包含140个标记的木薯分子遗传连锁图谱,其中EST-SSR标记111个,SSR标记22个,SRAP标记7个;共21个连锁群,其中连锁群1和3（LG1、LG3）上的标记位点最多（15个）,LG21标记位点最少（2个）。此遗传连锁图谱的总长度为1314.775 cM,单个连锁群最长为132.904 cM（LG3）,最短为0.431 cM（LG19）,标记间平均长度9.391 cM。     

冀豆12遗传图谱初步构建

以优良大豆品种冀豆12与野生大豆ZYD02738杂交建立基础群体,利用F2为作图群体,研究SSR标记位点在该群体中的多态性、偏分离并构建遗传图谱.结果表明,两亲本间SSR位点多态性比例79.9%,偏分离位点比例9.7%,构建的遗传图谱包含25个连锁群,总长度837.1 cM,标记间平均距离11.2 cM,标记间排列顺序与公共连锁图一致性较强.该研究为国内学者研究冀豆12遗传网络和重要农艺性状的基因、QTL定位等研究奠定了初步基础.     

山农01-35×藁城9411重组自交系遗传图谱构建及粒重QTL分析

为利用分子遗传图谱进行小麦产量数量性状位点定位分析,以大粒高产小麦品系山农01-35和强筋小麦藁城9411为亲本,衍生了含182个家系的重组自交系(RIL)F₈群体,用442个DArT标记、59个SSR标记和1个TaGW2-CAPS标记,构建了包括29个连锁群的分子遗传图谱,总遗传长度为4 084.5 cM,标记间平均距离为8.13 cM。定位了54个新标记位点,包括44个DArT和10个SSR标记,分布于除4D、6B、7B外的其他18条染色体上。用该分子遗传图谱和4个环境粒重表型值,共检测到7个影响粒重的加性QTL,分别位于1B、4B、5B、6A染色体,其中QGW4B-7、QGW5B-20和QGW6A-29在单环境分别定位和4个环境共同定位两种方法中均能检测到。QGW4B-7、QGW5B-12和QGW6A-29对粒重的贡献率均超过10%,为主效QTL。本研究结果可为小麦高产优质性状的QTL分析及分子标记辅助选择提供参考。     

一个新的白菜苗期TuMV-C4抗性主效QTL定位及连锁分子标记开发

为寻找与TuMV抗性基因紧密连锁的分子标记,选用高抗病毒病大白菜自交系91-112和高感病毒病自交系T12-19以及由二者为双亲构建的包含100个株系的DH群体为材料,通过SSR和InDel标记的遗传分析,在A09上定位了一个新的与大白菜苗期TuMV-C4抗性相关的主效QTL位点BrTuA09。在此基础上,针对该QTL位点所在的标记区间,根据作图群体双亲的重测序结果,设计合成27对引物,其中11个InDel在双亲间具有多态性,且条带单一、扩增稳定;连锁分析发现,11个InDel标记均被定位在A09连锁群上BrTuA09的置信区间。利用BC1群体进行标记验证发现,这些标记对高抗单株选择的准确率均达到78%以上,可应用于分子标记辅助选择,为大白菜TuMV抗病分子育种奠定了良好的基础。     

小麦抗叶锈病基因Lr24的一个新STS标记

来源于长穗偃麦草的基因Lr24对小麦叶锈病具有很高的抗性,本研究旨在开发用于Lr24基因分子标记辅助育种的新的分子标记。从定位于小麦3D染色体的22对SSR、EST-SSR引物中筛选出4对揭示TcLr24多态性的引物,用468株F2抗感群体对这4对引物进一步检测,得到1个与Lr24共分离的EST-SSR标记Xcwem17。对该标记进行测序,并设计了STS引物。用该STS引物及已知的Lr24SCAR引物对试验群体进行验证,两对引物在该F2群体中均表现共分离,且Xcwem17可在TcLr24单基因系和已知含Lr24的农家品种泰山1号中可扩增出180bp单一条带,感病对照及其余7个近等基因系无扩增。该EST-SSR标记可直接用于分子标记辅助选择。     

利用DH群体构建大白菜分子遗传图谱

构建大白菜分子遗传图谱,为大白菜干烧心QTL定位和分析奠定基础。以大白菜感病品种B120和大白菜抗病品种黑227为亲本建立的DH系为作图群体,基于所筛选出的74对In Del标记和37对SSR标记构建分子遗传图谱。利用Join Map 4.0软件,初步构建了一张覆盖基因组长度为1 004.7 c M、平均图距为9.30 c M的大白菜遗传连锁图,该图谱包含12个连锁群、108个标记位点。该图谱能有效地用于大白菜干烧心QTL定位。     

A genetic linkage map of rhodesgrass based on an F1 pseudo-testcross population

The linkage relationships between 164 polymorphic amplified fragment length polymorphism (AFLP) and 25 restriction fragment length polymorphism (RFLP) fragments assayed in a pseudo‐testcross population generated from the mating of single genotypes from two divergent cultivars were used to construct female, ‘Katambora’ (‘Kat’) and male, ‘Tochirakukei’ (‘Toch’) parental genetic maps for rhodesgrass. The ‘Kat’ genetic map consists of 84 marker loci (72 AFLP and 12 RFLP markers) distributed on 14 linkage groups and spans a total length of 488.3 cM, with an average distance of 7.8 cM between adjacent markers. The ‘Toch’ genetic map consists of 61 marker loci (52 AFLP and nine RFLP) mapped on 12 linkage groups spanning a total length of 443.3 cM, with an average spacing of 9.0 cM between adjacent markers. About 23% of the markers remained unassigned. The level of segregation distortion observed in this cross was 11.1%. In both maps, linked duplicated RFLP loci were found. These linkage maps will serve as a starting point for linkage studies in rhodesgrass with potential application for marker‐assisted selection in breeding programmes.     

Different recombination frequencies in wheat doubled haploid populations obtained through maize pollination and anther culture

This study compared the meiotic recombination frequency between wheat doubled haploid (DH) populations obtained through two different methods, maize pollination (MP♀) and anther culture (AC♂). The comparison was based on a genetic linkage analysis, performed with DNA markers. Thirty-five polymorphic markers (15 SSR, 15 AFLP, 5 RAPD) were screened in MP♀ and AC♂ doubled haploids populations, derived from the same hybrid genotype (F₁ of ‘Eta’ × ‘Darkhan 15’). Nine linkage groups, comprising 35 loci (the MP♀ lines) and 31 loci (the AC♂ lines), were constructed. The linkage groups in both DH populations showed identical orders of markers, except for one group mapping to chromosome 6B. The MP♀ and AC♂ linkage maps differed significantly in recombination frequencies for corresponding intervals. In total, the AC♂ linkage map (495.5 cM) was 40.5% longer than the MP♀ map (352.8 cM), indicating a significantly higher meiotic recombination rate in pollen mother cells. The enhancement in recombination was visible in five of nine linkage groups, and in 7 intervals between individual loci out of 19 compared. Moreover, for 6 other intervals a lack of linkage was observed in the AC♂ population, as compared to the MP♀ map.     

TRAP molecular markers as a system for saturation of the genetic map of durum wheat

Target region amplification polymorphism (TRAP) is a relatively new PCR-based technique that detects large numbers of loci in a single reaction without extensive pre-PCR processing of samples. The aim of this study was to integrate TRAP markers in an EST-derived SSR linkage map of a RIL mapping population from the cross of the durum wheat cultivars Ciccio and Svevo, for a more general purpose of establishing a high-throughput system for genetic map saturation. Primer combinations producing PCR products with at least 4–5 polymorphic bands were selected and analyzed across the mapping population. The PCR reactions produced a total of 2,881 fragments with an average of 52 peaks per reaction. A total of 142 new TRAP markers were mapped and found to be randomly distributed in the genome. The total length of the map was 2,043.0 cM, with an average chromosome length of 145.9 cM. Homoeologous group one had the highest number of TRAP markers (38 loci) and the longest map length (407.9 cM) for a total of 87 markers, while the homoeologous group five had the lowest TRAP marker number (5 loci) and the shortest map length (232.5 cM). The distribution of markers among the seven homoeologous groups was random. The results indicate that TRAP is highly efficient in genetic mapping, generating a large number of markers scattered across the genome. This closes many existing gaps in marker coverage and may join otherwise separate linkage groups.     

A high-density integrative linkage map for <Emphasis Type="Italic">Gossypium hirsutum</Emphasis>

Sequence-related amplified polymorphism (SRAP) combined with SSRs, RAPDs, and RGAPs was used to construct a high density genetic map for a F₂ population derived from the cross DH962 (G. hirsutum accession) × Jimian5 (G. hirsutum cultivar). A total of 4,096 SRAP primer combinations, 6310 SSRs, 600 RAPDs, and 10 RGAPs produced 331, 156, 17 and 2 polymorphic loci, respectively. Among the 506 loci obtained, 471 loci (309 SRAPs, 144 SSRs, 16 RAPDs and 2 RGAPs) were assigned to 51 linkage groups. Of these, 29 linkage groups were assigned to corresponding chromosomes by SSR markers with known chromosome locations. The map covered 3070.2 cM with a mean density of 6.5 cM per locus. The segregation distortion in this population was 9.49%, and these distorted loci tend to cluster at the end of linkage groups or in minor clusters on linkage groups. The majority of SRAPs in this map provided an effective tool for map construction in G. hirsutum despite of its low polymorphism. This high-density linkage map will be useful for further genetic studies in Upland cotton, including mapping of loci controlling quantitative traits, and comparative and integrative analysis with other interspecific and intraspecific linkage maps in cotton.     

利用2个F_2群体整合中国豌豆高密度SSR遗传连锁图谱

豌豆(Pisum sativum L.)是一种重要的食用豆类作物,在全世界范围内广泛种植,既可作为人类食物,也可作为牲畜饲料。用SSR标记构建的遗传连锁图谱在豌豆和其他作物的标记辅助育种中发挥着重要的作用。尽管对豌豆遗传连锁作图的研究已有悠久历史,但公众可获得且可转移的SSR标记以及基于遗传独特的中国豌豆种质的高密度遗传连锁图谱仍然有限。为了获得更多可转移的SSR标记和中国豌豆的高密度遗传连锁图谱,本研究首先从自主开发和文献获取的12,491个全基因组SSR标记中筛选了617个多态性SSR标记,并用于G0003973×G0005527 F_2群体遗传连锁图谱的加密。加密后的图谱全长扩展到5330.6 cM,包含603个SSR标记,标记平均间距离8.8 cM,相比之前的图谱有明显改善。基于上述结果,我们又筛选了119个具有多态性的SSR标记,用于构建大样本W6-22600×W6-15174 F_2群体的遗传连锁图谱,新图谱累积长度为1127.1 cM,包含118个SSR标记,装配在7条连锁群上。最后,将来自以上2个遗传图谱的数据进行整合,得到了一张覆盖范围6592.6 cM的整合图谱,包含668个SSR标记,由509个基因组SSR、134个EST-SSR和25个锚定标记组成,分布在7条连锁群上。这些SSR标记和遗传连锁图谱将为豌豆的遗传研究和标记辅助育种提供有力工具。     

A skeletal linkage map of Hordeum bulbosum L. and comparative mapping with barley (H. vulgare L.)

A restriction fragment length polymorphism (RFLP) based linkage map of a cross between two diploid Hordeum bulbosum (2n = 2x = 14) clones, PB1 and PB11, was constructed from 46 recombinant progeny clones. Since both parents are heterozygous, separate and combined parental maps were constructed. All of the RFLP markers screened had previously been mapped in barley (H. vulgare L.) so that comparative maps could be produced. The PB1 linkage map consists of 20 RFLP marker loci assigned to four linkage groups covering 94.3 cM. The PB11 linkage map consists of 27 RFLP marker loci assigned to six linkage groups covering 149.1 cM. Thirteen markers polymorphic in both parents were used as ‘anchors’ to create a combined linkage map consisting of 38 loci assigned to six linkage groups and covering a genetic distance of 198 cM. Marker order was highly conserved in a comparison with the linkage map of H. vulgare (Laurie etal., 1995). However, in contrast, the genetic distances for the same markers were very different being 649 cM and 198 cM respectively, a genetic distance ratio of 1: 3.3. Thus although the map was short, it can be presumed to cover half the genome of H. bulbosum. This study provides further confirmation of the close relationship between the two species and gives a basis for the development of marker mediated introgression through interspecific hybridisation between the two species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Linkage fine-mapping and QTLs affecting morpho-agronomic traits of a Mesoamerican × Andean RIL common bean population

This paper proposes the construction of a genetic linkage map with 376 recombinant inbred lines (RILs) derived from a cross between Mesoamerican?×?Andean common bean (Phaseolus vulgaris L) parents based on single nucleotide polymorphism (SNP) markers; and to detect quantitative trait loci (QTLs) associated with seven morpho-agronomic traits: number of days to flowering (DF), number of days to maturity (DM) or crop cycle; plant architecture (ARC); seed yield (YLD); degree of seed flatness (SF); seed shape (SS); and 100-seed weight (SW). A total of 3060 polymorphic SNP markers were used and 2041 segregated at a 1:1 ratio in the RIL population, as expected. These markers were subjected to linkage analysis in each chromosome. The genetic linkage analysis resulted in linkage maps with a total of 1962 markers spanning 1079.21 cM. A total of 29 QTLs associated with seven morpho-agronomic traits were detected on the 11 chromosomes, which explained between 3.83 and 32.92% of the phenotypic variation in DF. A total of 18 candidate genes associated with the detected QTLs were identified and related with biological processes, molecular functions and cellular components.     

甘蓝型油菜遗传图谱的构建及芥酸含量的QTL分析

一个由甘蓝型油菜品种Quantum (黄花、低芥酸)和人工合成的甘蓝型油菜品系No.2127-17（白花、高芥酸）为亲本材料建立的DH群体中芥酸呈现单基因的遗传模式。为了发展与芥酸紧密连锁的分子标记对其实行有效的控制,随机选择121个结实正常的DH系为作图群体,利用SSR和RAPD标记构建了一张甘蓝型油菜的遗传连锁图谱。在亲本间检测     

Construction of a linkage map for quantitative trait loci associated with economically important traits in creeping bentgrass (Agrostis stolonifera L.)

Creeping bentgrass (Agrostis stolonifera L.) is the most widely cultivated and high-value turfgrass species. Genetic linkage maps of creeping bentgrass were constructed for quantitative trait loci (QTL) analysis of gray snow mold (Typhula incarnata) resistance, recovery and leaf width. A segregating population of 188 pseudo-F₂ progeny was developed by two-way pseudo-testcross mapping strategy. Amplified fragment length polymorphism, new developed Agrostis specific expressed sequence tag-single sequence repeat (SSR), random amplified polymorphic DNA and genomic SSR markers corresponding to DNA polymorphisms heterozygous in one parent and null in the other, were scored and placed on two separate genetic linkage maps, representing each parent. In the male parent map, 100 markers were mapped to 14 linkage groups covering a total length of 793?cM with an average interval of 8.2?cM. In the female parent map, 146 markers were clustered in another 14 linkage groups spanning 805?cM with an average distance of 5.9?cM between adjacent markers. We identified three putative QTL for leaf width and one QTL for snow mold disease resistance. The construction of a linkage map and QTL analysis are expected to facilitate the development of disease resistant creeping bentgrass cultivars by using molecular marker-assisted selection.