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1.
张磊  张宝石 《植物学报》2007,24(4):553-560
作物的许多重要农艺性状属于数量性状, 鉴定和发掘控制数量性状的基因及其优异的等位变异, 并使之快速应用于育种实践是新时期作物科学家和育种学家所面临的重大课题。本文从QTL作图、QTL的精细定位与图位克隆、QTL近等基因系和染色体片断代换系的建立以及基于LD的关联分析等方面对植物数量性状的研究进展进行了讨论, 提出了以植物基因组学技术为平台, 将QTL作图与关联分析方法相结合, 是进行数量性状遗传机理研究同时服务于作物育种实践的有效途径。  相似文献   

2.
植物数量性状基因的定位与克隆   总被引:1,自引:0,他引:1  
张磊  张宝石 《植物学通报》2007,24(4):553-560
作物的许多重要农艺性状属于数量性状,鉴定和发掘控制数量性状的基因及其优异的等位变异,并使之快速应用于育种实践是新时期作物科学家和育种学家所面临的重大课题。本文从QTL作图、QTL的精细定位与图位克隆、QTL近等基因系和染色体片断代换系的建立以及基于LD的关联分析等方面对植物数量性状的研究进展进行了讨论,提出了以植物基因组学技术为平台,将QTL作图与关联分析方法相结合,是进行数量性状遗传机理研究同时服务于作物育种实践的有效途径。  相似文献   

3.
水稻QTL图位克隆的特征分析   总被引:5,自引:1,他引:4       下载免费PDF全文
姜树坤  徐正进  陈温福 《遗传》2008,30(9):1121-1126
图位克隆作为基因克隆的最有效手段, 在水稻QTL克隆方面取得了很大的进展。文章通过分析近年来关于水稻QTL图位克隆的15个成功案例, 总结了水稻QTL图位克隆的几个重要特征: (1) 亲本杂交类型为种间或亚种间杂交, 双亲的目标性状差异显著; (2) 目标QTL为主效, 一般能解释大部分的表型变异; (3) 物理图距一般小于40 kb; (4)初级定位结果准确, 精细定位群体大于6 000(隐性群体不小于1 500)单株。文章还对QTL图位克隆的难点及解决方法进行了有益的探讨。  相似文献   

4.
作物数量性状(QTL)基因研究进展   总被引:1,自引:0,他引:1  
从作物数量性状基因座QTL(quantitative trait locus)作图群体类型及特点,QTL定位的原理和方法,作物QTL研究现状,以及QTL精细定位、克隆、利用等方面进行了综述。对作物QTL分子标记辅助选择育种进行了探讨,并对目前QTL定位中存在的问题和今后QTL的研究方向提出了一些思考。  相似文献   

5.
近年来,分子数量遗传学的快速发展,使作物复杂数量性状尤其是经济性状的QTL研究取得了巨大进展,大大促进了复杂数量性状的遗传改良和分子操纵。本文从分子标记连锁图谱的构建、QTL定位力方法及效应分析、精细定位和QTL验证及应用等方面综述了二十多年来作物QTL的研究进展,讨论当前QTL研究中存在的问题,并展望了作物QTL研究的发展前景。  相似文献   

6.
作物数量性状基因研究进展   总被引:19,自引:0,他引:19  
邢永忠  徐才国 《遗传》2001,23(5):498-502
分子生物技术的发展对作物数量性状基因(QTL)研究提供了条件,不同的定位群体各有其特点,相继出现的QTL定位也逐步完善。大量的研究揭示了QTL的基本特征,剖析了重要农艺4性状的遗传基础,给作物遗传改良带来了新的策略,不断深入的研究已经完成了特定的QTL的精细定位和克隆。本从QTL的定位群体,定位方法,研究现状,精细定位与克隆,以及QTL利用等方面对作物数量性状基因的研究进行了综述。  相似文献   

7.
作物耐旱性QTL定位和分析的思路   总被引:1,自引:1,他引:0  
干旱是非生物胁迫中对作物生长和产量影响最严重的胁迫之一.作物的耐旱性受数量性状位点(QTL)的控制,存在复杂的基因/QTL互作和与环境的互作.对作物耐旱相关性状QTL进行定位和分析是耐旱研究的重点之一.本文通过对目前研究中涉及到的作物耐旱性特点、耐旱QTL分析的技术路线与新方法,表型鉴定以及耐旱性QTL互作分析等方面进行了比较系统的阐述,旨在为作物耐旱性QTL定位及未来的分子标记辅助选择提供有益的借鉴.  相似文献   

8.
分子生物技术的发展对作物数量性状基因(QTL)研究提供了条件,不同的定位群体各有其特点,相继出现的QTL定位方法也逐步完善.大量的研究揭示了QTL的基本特征,剖析了重要农艺性状的遗传基础,给作物遗传改良带来了新的策略,不断深入的研究已经完成了特定QTL的精细定位和克隆.本文从QTL的定位群体,定位方法,研究现状,精细定位与克隆,以及QTL利用等方面对作物数量性状基因的研究进行了综述。 Abstract:With the rapid development of molecular biotechnology,QTL analyses were executed for a lot of important agronomic traits in many crops.Different experimental populations and mapping methods had their own advantages in QTL analysis.Amounts of studies paid attention to locate the QTLs for important traits,and others tried to disect the genetic bases using molecular markers.Near isogenic lines were the best populations for QTL fine mapping and positional cloning,A few studies had been reported their results on materials with improvement traits using marker-assisted selection.This paper summarizes the recent progress on QTL mapping populations and methods,the status of QTL locating,QTL fine mapping and positional cloning,and QTL.application in breeding.  相似文献   

9.
《遗传》2016,(11)
大豆(Glycine max(L.)Merill)是重要的粮食作物和经济作物,盐胁迫能造成大豆产量的大幅度降低。本文综述了通过正向遗传学手段获得的大豆耐盐数量性状位点(Quantitative trait locus,QTL)以及通过反向遗传学方法获得的大豆耐盐功能基因方面的研究进展。目前,正向遗传学发掘基因主要有图位克隆(Map-based cloning)和全基因组关联分析(Genome-wide association study,GWAS)两种方案,其中通过图位克隆在大豆中已经获得了6个耐盐QTL位点并且定位了1个重要的耐盐基因;利用GWAS在大豆中获得了1个耐盐功能基因。利用反向遗传学在大豆中获得了大量的耐盐相关功能基因并在模式植物中验证了其功能,主要包括离子转运蛋白基因和转录因子基因。这些研究为揭示大豆耐盐分子机制以及通过分子标记辅助育种或转基因技术创制耐盐大豆奠定了基础。  相似文献   

10.
图位基因克隆是最近几十年中发展并逐步完善起来的基因分离及研究方法。紧密连锁分子标记的获得及DNA大片段克隆文库的建立是顺利进行图位基因克隆的重要条件,而对于那些数量性状基因(QTLs)的克隆更显示了其优越性。  相似文献   

11.
Molecular diversity, structure and domestication of grasses   总被引:19,自引:0,他引:19  
Map-based cloning has been considered problematic for isolating quantitative trait loci (QTLs) due to the confounding phenotypic effects of environment and other QTLs. However, five recent studies, all in plants, have succeeded in cloning QTLs using map-based methods. We review the important features of these studies and evaluate the prospects for broader application of the techniques. Successful map-based cloning requires that QTLs represent single genes that can be isolated in near-isogenic lines, and that genotypes can be unambiguously inferred by progeny testing. In plants or animals for which map-based cloning of genes with discrete phenotypes is feasible, the modified procedures required for QTLs should not be limiting in most cases. The choice between map-based cloning and alternative methods will depend on details of the species and traits being studied.  相似文献   

12.
Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield component QTLs, and to map QTLs for biomass-related traits. Many of the previously identified QTLs for yield and its component traits were confirmed and were localized to narrower intervals. Four novel QTLs one each for shoot biomass (Xcfa2262-Xbcd366), total biomass (wPt2740-Xcfa2076), kernels/spike (KPS) (Xwmc664-Xbarc67), and Pseudocercosporella induced lodging (PsIL) were also detected. The major QTLs identified for grain yield (GY), KPS, grain volume weight (GVWT) and spikes per square meter (SPSM) respectively explained 23.2%, 24.2%, 20.5% and 20.2% of the phenotypic variation. Comparison of the genetic map with the integrated physical map allowed estimation of recombination frequency in the regions of interest and suggested that QTLs for grain yield detected in the marker intervals Xcdo549-Xbarc310 and Xpsp3047-Xbarc356 reside in the high-recombination regions, thus should be amenable to map-based cloning. On the other hand, QTLs for KPS and SPSM flanked by markers Xwmc664 and Xwmc489 mapped in the low-recombination region thus are not suitable for map-based cloning. Comparisons with the rice (Oryza sativa L.) genomic DNA sequence identified 11 candidate genes (CGs) for yield and yield related QTLs of which chromosomal location of two (CKX2 and GID2-like) was confirmed using wheat aneuploids. This study provides necessary information to perform high-resolution mapping for map-based cloning and for CG-based cloning of yield QTLs.  相似文献   

13.
Believe it or not, QTLs are accurate!   总被引:11,自引:0,他引:11  
It is generally believed that mapping quantitative trait loci (QTLs) does not accurately position genes underlying polygenic traits on the genome, which limits the application of QTL analysis in marker-assisted selection and gene discovery. However, now that a few plant QTLs have been cloned or accurately tagged, it appears that they might be accurate to within 2cM or less. This means that there will be circumstances when map-based cloning using only original mapping data would be a realistic option that avoids time-consuming and expensive fine mapping. Acceptance of this view would enhance the value of past and future mapping experiments, particularly those revealing small and environmentally sensitive QTLs that are often considered intractable at the molecular level.  相似文献   

14.
Chromosome segment substitution lines (CSSLs) are a powerful alternative for locating quantitative trait loci (QTL), analyzing gene interactions, and providing starting materials for map-based cloning projects. We report the development and characterization of a CSSL library of a U.S. weedy rice accession ‘PSRR-1’ with genome-wide coverage in an adapted rice cultivar ‘Bengal’ background. The majority of the CSSLs carried a single defined weedy rice segment with an average introgression segment of 2.8 % of the donor genome. QTL mapping results for several agronomic and domestication traits from the CSSL population were compared with those obtained from two recombinant inbred line (RIL) populations involving the same weedy rice accession. There was congruence of major effect QTLs between both types of populations, but new and additional QTLs were detected in the CSSL population. Although, three major effect QTLs for plant height were detected on chromosomes 1, 4, and 8 in the CSSL population, the latter two escaped detection in both RIL populations. Since this was observed for many traits, epistasis may play a major role for the phenotypic variation observed in weedy rice. High levels of shattering and seed dormancy in weedy rice might result from an accumulation of many small effect QTLs. Several CSSLs with desirable agronomic traits (e.g. longer panicles, longer grains, and higher seed weight) identified in this study could be useful for rice breeding. Since weedy rice is a reservoir of genes for many weedy and agronomic attributes, the CSSL library will serve as a valuable resource to discover latent genetic diversity for improving crop productivity and understanding the plant domestication process through cloning and characterization of the underlying genes.  相似文献   

15.
Yield-related QTLs and Their Applications in Rice Genetic Improvement   总被引:1,自引:0,他引:1  
Grain yield is one of the most important indexes in rice breeding,which is governed by quantitative trait loci (QTLs).Different map-ping populations have been used to explore the QTLs controlling yield related traits.Primary populations such as F 2 and recombi-nant inbred line populations have been widely used to discover QTLs in rice genome-wide,with hundreds of yield-related QTLs detected.Advanced populations such as near isogenic lines (NILs) are efficient to further fine-map and clone target QTLs.NILs for primarily identified QTLs have been proposed and confirmed to be the ideal population for map-based cloning.To date,20 QTLs directly affecting rice grain yield and its components have been cloned with NIL-F 2 populations,and 14 new grain yield QTLs have been validated in the NILs.The molecular mechanisms of a continuously increasing number of genes are being unveiled,which aids in the understanding of the formation of grain yield.Favorable alleles for rice breeding have been ’mined’ from natural cultivars and wild rice by association analysis of known functional genes with target trait performance.Reasonable combination of favorable alleles has the potential to increase grain yield via use of functional marker assisted selection.  相似文献   

16.
Mapping quantitative trait loci (QTLs) is a foundation for molecular marker-assisted selection and map-based gene cloning. During the past decade, numerous QTLs for seed yield (SY) and yield-related traits in Brassica napus L. have been identified. However, integration of these results in order to compare QTLs from different mapping populations has not been undertaken, due to the lack of common molecular markers between studies. Using previously reported Brassica rapa and Brassica oleracea genome sequences, we carried out in silico integration of 1,960 QTLs associated with 13 SY and yield-related traits from 15 B. napus mapping experiments over the last decade. A total of 736 SY and yield-related QTLs were mapped onto 283 loci in the A and C genomes of B. napus. These QTLs were unevenly distributed across the 19 B. napus chromosomes, with the most on chromosome A3 and the least on chromosome C6. Our integrated QTL map identified 142 loci where the conserved QTLs were detected and 25 multifunctional loci, mostly for the traits of flowering time (FT), plant height, 1,000-seed weight, maturity time and SY. These conserved QTLs and multifunctional loci may result from pleiotropism or clustered genes. At the same time, a total of 146 genes underlying the QTLs for FT and other yield-related traits were identified by comparative mapping with the Arabidopsis genome. These results facilitate the retrieval of B. napus SY and yield-related QTLs for research communities, increase the density of targeted QTL-linked markers, validate the existence of QTLs across different populations, and advance the fine mapping of genes.  相似文献   

17.
分子标记在作物育种中的应用   总被引:17,自引:0,他引:17  
近20年来发展了多种分子标记,使作物育种学家有可能直接根据基因型而不只是表现型进行选择,在作物育种的各个方面具有重要的利用价值。本文简要综述了分子标记在作物育种方面的有关应用。主要内容有:(1)分子图谱构建与基因定位;(2)DNA指纹库的建立;(3)标记辅助选择;(4)F1杂种优势分析;(5)基于图谱克隆基因。  相似文献   

18.
For discovering the quantitative trait loci (QTLs) contributing to early seedling growth and drought tolerance during germination, conditional and unconditional analyses of 12 traits of wheat seedlings: coleoptile length, seedling height, longest root length, root number, seedling fresh weight, stem and leaves fresh weight, root fresh weight, seedling dry weight, stem and leaves dry weight, root dry weight, root to shoot fresh weight ratio, root-to-shoot dry weight ratio, were conducted under two water conditions using two F8:9 recombinant inbred line (RIL) populations. The results of unconditional analysis are as follows: 88 QTLs accounting for 3.33–77.01% of the phenotypic variations were detected on chromosomes 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 4A, 4B, 4D, 5A, 5B, 5D, 6A, 6B, 6D, 7A, 7B and 7D. Among these QTLs, 19 were main-effect QTLs with a contribution rate greater than 10%. The results of the conditional QTL analysis of 12 traits under osmotic stress on normal water conditions were as follows: altogether 22 QTLs concerned with drought tolerance were detected on chromosomes 1B, 2A, 2B, 3B, 4A, 5D, 6A, 6D, 7B, and 7D. Of these QTLs, six were main-effect QTLs. These 22 QTLs were all special loci directly concerned with drought tolerance and most of them could not be detected by unconditional analysis. The finding of these QTLs has an important significance for fine-mapping technique, map-based cloning, and molecular marker-assisted selection of early seedling traits, such as growth and drought tolerance.  相似文献   

19.
The identification of quantitative trait loci (QTLs) affecting agronomically important traits enable to understand their underlying genetic mechanisms and genetic basis of their complex interactions. The aim of the present study was to detect QTLs for 12 agronomic traits related to staygreen, plant early development, grain yield and its components, and some growth characters by analyzing replicated phenotypic datasets from three crop seasons, using the population of 168 F7 RILs of the cross 296B × IS18551. In addition, we report mapping of a subset of genic-microsatellite markers. A linkage map was constructed with 152 marker loci comprising 149 microsatellites (100 genomic- and 49 genic-microsatellites) and three morphological markers. QTL analysis was performed by using MQM approach. Forty-nine QTLs were detected, across environments or in individual environments, with 1–9 QTLs for each trait. Individual QTL accounted for 5.2–50.4% of phenotypic variance. Several genomic regions affected multiple traits, suggesting the phenomenon of pleiotropy or tight linkage. Stable QTLs were identified for studied traits across different environments, and genetic backgrounds by comparing the QTLs in the study with previously reported QTLs in sorghum. Of the 49 mapped genic-markers, 18 were detected associating either closely or exactly as the QTL positions of agronomic traits. EST marker Dsenhsbm19, coding for a key regulator (EIL-1) of ethylene biosynthesis, was identified co-located with the QTLs for plant early development and staygreen trait, a probable candidate gene for these traits. Similarly, such exact co-locations between EST markers and QTLs were observed in four other instances. Collectively, the QTLs/markers identified in the study are likely candidates for improving the sorghum performance through MAS and map-based gene isolations.  相似文献   

20.
Yield-enhancing quantitative trait loci (QTLs) from wild species   总被引:1,自引:0,他引:1  
Wild species of crop plants are increasingly being used to improve various agronomic traits including yield in cultivars. Dense molecular maps have enabled mapping of quantitative trait loci (QTLs) for complex traits such as yield. QTLs for increased yield have been identified from wild relatives of several crop plants. Advanced backcross QTL analysis has been used to identify naturally occurring favorable QTL alleles for yield and minimize the effect of unwanted alleles from wild species. Yield QTLs from wild species are distributed on almost all chromosomes but more often in some regions. Many QTLs for yield and related traits derived from different wild accessions or species map to identical chromosomal regions. QTLs for highly correlated yield associated traits are also often co-located implying linkage or pleiotropic effects. Many QTLs have been detected in more than one environment and in more than one genetic background. The overall direction of effect of some QTLs however, may vary with genetic context. Thus, there is evidence of stable and consistent major effect yield-enhancing QTLs derived from wild species in several crops. Such QTLs are good targets for use in marker assisted selection though their context-dependency is a major constraint. Literature on yield QTLs mapped from wild species is summarized with special reference to rice and tomato.  相似文献   

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