Quantitative trait locus qtl mapping is a highly effective approach for studying genetically complex forms of plant disease resistance. The progeny of 234 f2 plants and the two parents were planted in. A quantitative trait locus qtl is a locus section of dna that correlates with variation of a quantitative trait in the phenotype of a population of organisms. Quantitative trait locus qtl mapping has been applied to detect the genetic basis of salt tolerance in many plants 8, which provides valuable information for further. Traditional qtl approach uses standard biparental mapping populations o f2 or ri these have a limited number of recombination events o result is that the qtl covers many cm additional steps required to narrow qtl or clone gene difficult to discover closely linked markers or the causative gene. Chapter 5 basics of linkage and gene mapping 45 chapter 5. Qtl mapping in polyploid genomes summary single marker analysis sma involves ttest, anova, or linear regression approach interval mapping is based on joint segregation of a pair of adjacent markers cim is a combination of im and multiple regression and is desirable among the three qtl mapping in autopolyploids require different. Mapping dynamic qtl for plant height in triticale bmc. The phenotypes and the frequencies of the progeny from the test crosses are. Employing multipleline cross qtl mapping we identified 15 qtl for ph1, 18 for ph2 and 8 for ph3 table 2, figure 2. Qtl mapping and its applications in crop plants 4 wheat and maize. The joint segregating patterns of markers, in conjunction with phenotypic and pedigree information, provides additional information about the genetic basis of quantitative traits, including the number and chromosomal locations of qtl, the mode of gene action, and sizes effects of individual qtl. Currently, most ld mapping studies in plants use r2 for ld quantification because it also provides information about the correlation between markers and qtl of. Linkage loci that are close enough together on the same chromosome to deviate from independent assortment are said to display genetic linkage 4.
Quantitative trait locus qtl mapping with a highdensity genetic linkage map, including 2,496 recombinant bins, was used to uncover the genetic basis of these. Over the past two decades, linkage mapping has been commonly used in various plant species, and many qtl have been cloned or tagged 1. Status and prospects of association mapping in plants. Rqtl is an extensible, interactive environment for the mapping of quantitative trait loci qtl in experimental crosses. In this study, we quantified 106 traits from a maize zea mays recombinant inbred line population n. Introduction one of the many goals of plant geneticists and breeders pertains to the explanation of. Two strategies have been widely applied to genetic mapping in plants. Analysis of the genetic basis of plant heightrelated.
With increasing demand for novel traits in crop breeding, the plant research community faces the challenge of quantitatively analyzing the structure and function of large numbers of plants. It will be a useful reference for conventional plant breeders, physiologists, pathologists and other plant scientists. A clear goal of highthroughput phenotyping is to bridge the gap between genomics and phenomics. Qtl analysis is predicated on looking for associations between the quantitative trait and the marker alleles segregating in the population. Mapping qtl for agronomic traits in breeding populations. Backcross bc, f 2, doubled haploid, testcross progenies, halfsib and fullsib families, f 2 derived lines, recombinant inbred lines. Ml and outfire05 were both major qtl and explained, respectively, 14. In crops like maize, a broad ruleofthethumb is to cover each of the chromosomal bin locations with at least one or two polymorphic molecular markers. Utilization of molecular markers for pgrfa characterization and prebreeding for climate changes aug. Introduction to qtl mapping in plants annals of plant.
For qtl mapping, common statistical tools and techniques employed in project management of complex and embedded systems pdf qtl analysis. Aarts1 1laboratory 2 of genetics, wageningen university, droevendaalsesteeg 1, 6708 pb wageningen, the netherlands. Highdensity genetic map construction associated with quantitative trait locus qtl mapping provides an effective way to facilitate trait. Flavonoids are important components that confer upon tea plants a unique flavour and health functions.
This is often an early step in identifying and sequencing the actual genes that cause the trait variation. Mapping of a major qtl for salt tolerance of mature field. Locations of markers goals identify the or at least one genomic region, called quantitative trait locus qtl, that contributes to variation in the trait. Seed size is also a vital fitness trait in flowering plants and plays a. Introduction many population structures have been used for qtl detection and mapping in plants. Qtgseq accelerates qtl fine mapping through qtl partitioning. Trait codes, their performance and broad sense heritability are presented in table 1. Qtl mapping studies have been reported in most crop plants for diverse. Genomewide nested association mapping of quantitative resistance to northern leaf blight in maize jesse a. Genetic analysis of agronomic traits associated with plant. Additionally, the same type of segregating population derived from different parental lines likely provide different qtl identification results, including different location, number, and.
Aarts1 1laboratory 2 of genetics, wageningen university, droevendaalsesteeg 1, 6708 pb wageningen, the netherlands department 3. Two different plants plant 1 and plant 2 that were heterozygous for each trait were test crossed to plants that were homozygous for th e recessive alleles. It is implemented as an addon package for the freely available and widely used statistical languagesoftware r r development core team, 2010. Genomewide nested association mapping of quantitative. Introduction to quantitative trait locus qtl mapping. With qtl mapping, the roles of specific resistance loci can be described, racespecificity of partial resistance genes can be assessed and interactions. Pdf on apr 1, 2015, rukam singh tomar and others published introduction to qtl mapping in plants find, read and cite all the research you need on researchgate. Oct 17, 2016 qtl mapping in polyploid genomes summary single marker analysis sma involves ttest, anova, or linear regression approach interval mapping is based on joint segregation of a pair of adjacent markers cim is a combination of im and multiple regression and is desirable among the three qtl mapping in autopolyploids require different. For cim, model 6 of zmaoqtl module was applied for detecting qtl and their effects. By considering these qtl interactions in the qtl mapping model of. Status and prospects of association mapping in plants chengsong zhu, michael gore, edward s. Qtls are mapped by identifying which molecular markers such as snps or aflps correlate with an observed trait. The genome was scanned every 1 cm between markers and putative qtls with a window size of 10 cm.
With qtl mapping, the roles of specific resistance loci can be described, racespecificity of partial resistance genes can be assessed, and interactions between resistance genes. Highdensity snp linkage map construction and qtl mapping. Gent nahla bassil paul matthews emily buck ron beatson received. The line is least heterozygous within a region between two dna markers, c11635 and p3b2, on chromosome 6.
Interestingly, we observed three qtl for plant height that were identified at all three time points, some that were identified for two time points but also qtl that were specific for either ph1, ph2 or ph3 figure 3. Pdf crop modeling, qtl mapping, and their complementary. The primary requirement is for two parental strains that have differences between them in the alleles that affect. Buckler, and jianming yu abstract there is tremendous interest in using association mapping to identify genes responsible for quantitative variation of complex traits with agricultural and evolutionary importance. Marker assisted selection or marker aided selection mas is an indirect selection process where a trait of interest is selected based on a marker morphological, biochemical or dnarna variation linked to a trait of interest e. Review of statistical methods for qtl mapping in experimental crosses karl w. Highthroughput phenotyping and qtl mapping reveals the. Qtl mapping in both plants and animals involves just a few basic steps 11. With this new qtl mapping strategy, and jansen, 2001. The parental lines contrasted for most of the traits at both sites table 1. The genome was scanned every 1 cm between markers and putative qtls with a. Qtl mapping of powdery mildew susceptibility in hop humulus lupulus l. Genetic resistance is the most costeffective and environmentally appropriate approach to disease management in.
Qtl mapping for each location was conducted by compositeinterval mapping cim in windows qtl cartographer version 2. Qtl mapping according to the suttons chromosomal theory of inheritance, genes markers or loci segregate via chromosome recombination during meiosis i. For example,if all the tall plants among 500 individual corn plants of varying height have a particular allele of a genetic marker,then there is a very high probability that a qtl for plant. The objective of genetic mapping is to identify qtl responsible for natural phenotypic variation. Review of statistical methods for qtl mapping in experimental. This paper will be a key reference for the beginners and research scholars who are involved in qtl mapping in crop plants. Qtl analysis using multienvironment phenotyping data from f. Compared to 673 plants, 305e40 plants set longer, narrower and lighter fruits, which developed on a longer peduncle and formed fewer seed locules and a green ring in the. Plants are used as model organisms for the study of quantitative traits because they are particularly amenable to highresolution mapping and positional cloning. Analysis of the genetic basis of plant heightrelated traits. However, the traditional breeding method for selecting a cultivar with a high or unique flavonoid content is time consuming and labour intensive. Qtl mapping for plant height in rice at multiple time points revealed many loci that were specific for one or a few of the time points.
R qtl is an extensible, interactive environment for the mapping of quantitative trait loci qtl in experimental crosses. With qtl mapping, the roles of specific resistance loci can be described, racespecificity of partial resistance genes can be assessed, and interactions between resistance genes, plant development, and the environment can be analyzed. Qtl mapping and its applications in crop plants 2 qtl mapping studies have been reported in most crop plants for diverse traits including yield, quality, disease and insect resistance, abiotic stress tolerance, and environmental adaptation. The process of constructing linkage maps and conducting qtl analysis to identify genomic regions associated with traitsis known as qtl mapping 3 4. Pdf introduction to qtl mapping in plants researchgate. It has enabled detailed understanding of the genetic component of many major traits in plant breeding. Detect quantitative trait loci testing for association between a phenotypic trait and. Quantitative trait locus, linkage map, molecular marker. Progeny of plant 1 progeny of plant 2 coloured kernels, green plants 12 45. Genotype environment interaction qtl mapping in plants. Nils can serve as a valuable genetic mapping resource for maize breeders and geneticists. A qtl is defined as a region of the genome or locus of gene that is associated with an effect on a quantitative trait. Collect genotypic information on parents and offspring in the form of molecular markers scores. With the advent of codominant dna markers, it became possible to construct saturated genetic maps and to locate qtl for numerous phenotypes in plants, animals and humans.
Currently, most ld mapping studies in plants use r2 for ld quantification because it also provides information about the correlation between markers and qtl of interest flintgarcia et al. Abstract quantitative trait locus qtl mapping is a highly effective approach for studying genetically complex forms of plant disease resistance. Buckler, and jianming yu abstract there is tremendous interest in using association mapping to identify genes responsible for quantitative variation of complex traits with. Genetic mapping and qtl analysis for disease resistance. Qtl mapping in eggplant reveals clusters of yieldrelated. Here, a brief overview of the principle of qtl mapping, salient requirements. Qtl mapping and candidate gene mining for soybean seed weight. Ancient and modern perspectives article pdf available.
Each position in the genome, one at a time, is posited as the putative qtl. Quantitative traits can have varying phenotypic concentration. Genetic resistance is the most costeffective and environmentally appropriate approach to disease management in crop plants. Genetic mapping of quantitative trait loci in crops sciencedirect. Genetic mapping of quantitative trait loci in crops. Sotocerda 1,2 and sylvie cloutier 1 1cereal research center, agriculture and agrifood canada 2agriaquaculture nutritional genomic center, cgna r10c1001 genomics and bioinformatics unit 1canada 2chile 1. Employing triticale as model species for small grain cereals, busemeyer et al.
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