scholarly journals Development of a multiparent advanced generation intercross (MAGIC) population for genetic exploitation of complex traits in Brassica juncea: glucosinolate content as an example

2019 ◽  
Author(s):  
Tianya Wang ◽  
Wei Wan ◽  
Kunjiang Yu ◽  
Aimal Nawaz Khattak ◽  
Botao Ye ◽  
...  
Keyword(s):  
Association Mapping ◽  
Complex Traits ◽  
Quantitative Traits ◽  
Recombinant Inbred Lines ◽  
Glucosinolate Content ◽  
Intron Length Polymorphism ◽  
Whole Process ◽  
Specific Pcr ◽  
Advanced Generation ◽  
Magic Population

AbstractMultiparent advanced generation intercross (MAGIC) populations have recently been developed to allow the high-resolution mapping of complex quantitative traits. This article describes the development of one MAGIC population and verifies its potential application for mapping quantitative trait loci (QTLs) in B. juncea. The population was developed from eight founders with diverse traits and composed of 408 F6 recombinant inbred lines (RILs). To develop one rapid and simplified way for using the MAGIC population, a subset of 133 RILs as the primary mapping population were genotyped using 346 intron-length polymorphism (ILP) polymorphic markers. The population lacks significant signatures of population structure that are suitable for the analysis of complex traits. Genome-wide association mapping (GWAS) identified three major glucosinolate (GSL) QTLs of QGsl.ig01.1 on J01 for indole GSL (IG), QGsl.atg09.1 on J09 and QGsl.atg11.1 on J11 for aliphatic GSL (AG) and total GSL (TG). The candidate genes for QGsl.ig01.1, QGsl.atg09.1 and QGsl.atg11.1 are GSH1, GSL-ALK and MYB28, which are involved in converting glutamate and cysteine to γ–EC, the accumulation of glucoraphanin, and the whole process of AG metabolism, respectively. One effective method for association mapping of quantitative traits in the B. juncea MAGIC population is also suggested by utilization of the remaining 275 RILs and incorporation of the novel kompetitive allele specific PCR (KASP) technique. In addition to its QTL mapping purpose, the MAGIC population could also be potentially utilized in variety development by breeders.

scholarly journals Crafting for a better MAGIC: systematic design and test for multiparental advanced generation inter-cross population

2021 ◽  
Author(s):  
Chin Jian Yang ◽  
Rodney N. Edmondson ◽  
Hans-Peter Piepho ◽  
Wayne Powell ◽  
Ian Mackay
Keyword(s):  
Complex Traits ◽  
Recombinant Inbred Lines ◽  
Haplotype Diversity ◽  
R Package ◽  
Shiny App ◽  
New Varieties ◽  
Creativity And Innovation ◽  
Advanced Generation ◽  
Population Design ◽  
Magic Population

AbstractMultiparental advanced generation inter-cross (MAGIC) populations are valuable crop resources with a wide array of research uses including genetic mapping of complex traits, management of genetic resources and breeding of new varieties. Multiple founders are crossed to create a rich mosaic of highly recombined founder genomes in the MAGIC recombinant inbred lines (RILs). Many variations of MAGIC population designs exist; however, a large proportion of the currently available populations have been created empirically and based on similar designs. In our evaluations of five MAGIC populations, we found that the choice of designs has a large impact on the recombination landscape in the RILs. The most popular design used in many MAGIC populations has been shown to have a bias in recombinant haplotypes and low level of unique recombinant haplotypes, and therefore is not recommended. To address this problem and provide a remedy for the future, we have developed the “magicdesign” R package for creating and testing any MAGIC population design via simulation. A Shiny app version of the package is available as well. Our “magicdesign” package provides a unifying tool and a framework for creativity and innovation in MAGIC population designs. For example, using this package, we demonstrate that MAGIC population designs can be found which are very effective in creating haplotype diversity without the requirement for very large crossing programmes. Further, we show that interspersing cycles of crossing with cycles of selfing is effective in increasing haplotype diversity. These approaches are applicable in species which are hard to cross or in which resources are limited.

scholarly journals Crafting for a better MAGIC: systematic design and test for multiparental advanced generation inter-cross population

2021 ◽  
Author(s):  
Chin Jian Yang ◽  
Rodney N Edmondson ◽  
Hans-Peter Piepho ◽  
Wayne Powell ◽  
Ian Mackay
Keyword(s):  
Complex Traits ◽  
Recombinant Inbred Lines ◽  
Haplotype Diversity ◽  
R Package ◽  
Shiny App ◽  
New Varieties ◽  
Creativity And Innovation ◽  
Advanced Generation ◽  
Population Design ◽  
Magic Population

Abstract Multiparental advanced generation inter-cross (MAGIC) populations are valuable crop resources with a wide array of research uses including genetic mapping of complex traits, management of genetic resources and breeding of new varieties. Multiple founders are crossed to create a rich mosaic of highly recombined founder genomes in the MAGIC recombinant inbred lines (RILs). Many variations of MAGIC population designs exist; however, a large proportion of the currently available populations have been created empirically and based on similar designs. In our evaluations of five MAGIC populations, we found that the choice of designs has a large impact on the recombination landscape in the RILs. The most popular design used in many MAGIC populations has been shown to have a bias in recombinant haplotypes and low level of unique recombinant haplotypes, and therefore is not recommended. To address this problem and provide a remedy for the future, we have developed the “magicdesign” R package for creating and testing any MAGIC population design via simulation. A Shiny app version of the package is available as well. Our “magicdesign” package provides a unifying tool and a framework for creativity and innovation in MAGIC population designs. For example, using this package, we demonstrate that MAGIC population designs can be found which are very effective in creating haplotype diversity without the requirement for very large crossing programs. Further, we show that interspersing cycles of crossing with cycles of selfing is effective in increasing haplotype diversity. These approaches are applicable in species which are hard to cross or in which resources are limited.

scholarly journals Association mapping for maize stover yield and saccharification efficiency using a multiparent advanced generation intercross (MAGIC) population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. López-Malvar ◽  
A. Butron ◽  
R. A. Malvar ◽  
S. J. McQueen-Mason ◽  
L. Faas ◽  
...  
Keyword(s):  
Association Mapping ◽  
Genome Wide Association Study ◽  
Recombinant Inbred Lines ◽  
Nucleotide Polymorphisms ◽  
Maize Stover ◽  
A Genome ◽  
Stover Yield ◽  
Saccharification Efficiency ◽  
Advanced Generation ◽  
Magic Population

AbstractCellulosic ethanol derived from fast growing C4 grasses could become an alternative to finite fossil fuels. With the potential to generate a major source of lignocellulosic biomass, maize has gained importance as an outstanding model plant for studying the complex cell wall network and also to optimize crop breeding strategies in bioenergy grasses. A genome-wide association study (GWAS) was conducted using a subset of 408 Recombinant Inbred Lines (RILs) from a Multi-Parent Advanced Generation Intercross (MAGIC) Population in order to identify single nucleotide polymorphisms (SNPs) associated with yield and saccharification efficiency of maize stover. We identified 13 SNPs significantly associated with increased stover yield that corresponded to 13 QTL, and 2 SNPs significantly associated with improved saccharification efficiency, that could be clustered into 2 QTL. We have pointed out the most interesting SNPs to be implemented in breeding programs based on results from analyses of averaged and yearly data. Association mapping in this MAGIC population highlight genomic regions directly linked to traits that influence the final use of maize. Markers linked to these QTL could be used in genomic or marker-assisted selection programs to improve biomass quality for ethanol production. This study opens a possible optimisation path for improving the viability of second-generation biofuels.

scholarly journals TeoNAM: a nested association mapping population for domestication and agronomic trait analysis in maize

2019 ◽  
Author(s):  
Qiuyue Chen ◽  
Chin Jian Yang ◽  
Alessandra M. York ◽  
Wei Xue ◽  
Lora L. Daskalska ◽  
...  
Keyword(s):  
Association Mapping ◽  
Complex Traits ◽  
Agronomic Traits ◽  
Mapping Population ◽  
Allelic Variation ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Nested Association Mapping ◽  
Nested Association Mapping Population ◽  
Association Mapping Population

AbstractRecombinant inbred lines (RILs) are an important resource for mapping genes controlling complex traits in many species. While RIL populations have been developed for maize, a maize RIL population with multiple teosinte inbred lines as parents has been lacking. Here, we report a teosinte nested association mapping population (TeoNAM), derived from crossing five teosinte inbreds to the maize inbred line W22. The resulting 1257 BC1S4 RILs were genotyped with 51,544 SNPs, providing a high-density genetic map with a length of 1540 cM. On average, each RIL is 15% homozygous teosinte and 8% heterozygous. We performed joint linkage mapping (JLM) and genome-wide association study (GWAS) for 22 domestication and agronomic traits. A total of 255 QTLs from JLM were identified with many of these mapping to known genes or novel candidate genes. TeoNAM is a useful resource for QTL mapping for the discovery of novel allelic variation from teosinte. TeoNAM provides the first report that PROSTRATE GROWTH1, a rice domestication gene, is also a QTL associated with tillering in teosinte and maize. We detected multiple QTLs for flowering time and other traits for which the teosinte allele contributes to a more maize-like phenotype. Such QTL could be valuable in maize improvement.

scholarly journals A multi-parent advanced generation inter-cross population for genetic analysis of multiple traits in cowpea (Vigna unguiculata L. Walp.)

2017 ◽  
Author(s):  
Bao-Lam Huynh ◽  
Jeffrey D. Ehlers ◽  
Maria Munoz-Amatriain ◽  
Stefano Lonardi ◽  
Jansen R. P. Santos ◽  
...  
Keyword(s):  
Genetic Mapping ◽  
Vigna Unguiculata ◽  
Seed Quality ◽  
Agronomic Traits ◽  
Recombinant Inbred Lines ◽  
Sub Saharan Africa ◽  
Yield Potential ◽  
Breeding Populations ◽  
Advanced Generation ◽  
Magic Population

AbstractDevelopment and analysis of Multiparent Advanced Generation Inter-Cross (MAGIC) populations have been conducted with several crop plants to harness the potential for dissecting the genetic structure of traits and improving breeding populations. We developed a first MAGIC population for cowpea (Vigna unguiculata L. Walp.) from eight founder parents which are genetically diverse and carry many abiotic and biotic stress resistance, seed quality and agronomic traits relevant to cowpea improvement in sub-Saharan Africa (SSA) where cowpea is vitally important in the human diet and in local economies. The eight parents were inter-crossed using structured matings to ensure the population would have balanced representation from each of the founder parents, followed by single-seed descent, resulting in 365 F8 recombinant inbred lines (RILs) each carrying a mosaic of genome blocks contributed from all founders. This was confirmed by SNP genotyping with the cowpea Illumina 60K iSelect BeadArray. Following filtering to eliminate duplicates, sister lines and accidental selfing events, a core set of 305 F8 RILs was chosen as the primary population. The F8 lines were on average 99.74% homozygous while also diverse in agronomic traits including flowering time, growth habit, maturity, yield potential and seed characteristics across environments. Trait-associated SNPs were identified for most of the parental traits. Loci with major effects on photoperiod sensitivity and seed size were also verified by genetic mapping in biparental RIL populations. The distribution of recombination frequency varied considerably between chromosomes, with recombination hotspots distributed mostly in the telomeric regions. Due to its broad genetic base, this cowpea MAGIC population promises breakthroughs in genetic gain and high-resolution genetic mapping for gene discovery, enhancement of breeding populations and, for some lines, direct releases as new varieties.

scholarly journals The complex genetic architecture of recombination and structural variation in wheat uncovered using a large 8-founder MAGIC population

2019 ◽  
Author(s):  
Rohan Shah ◽  
B Emma Huang ◽  
Alex Whan ◽  
Marcus Newberry ◽  
Klara Verbyla ◽  
...  
Keyword(s):  
Bread Wheat ◽  
Complex Traits ◽  
Genetic Architecture ◽  
Structural Variation ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Genetic Effects ◽  
Ongoing Research ◽  
Significant Qtls ◽  
Magic Population

AbstractBackgroundIdentifying the genetic architecture of complex traits requires access to populations with sufficient genetic diversity and recombination. Multi-parent Advanced Generation InterCross (MAGIC) populations are a powerful resource due to their balanced population structure, allelic diversity and enhanced recombination. However, implementing a MAGIC population in complex polyploids such as wheat is not trivial, as wheat harbours many introgressions, inversions and other genetic factors that interfere with linkage mapping.ResultsBy utilising a comprehensive crossing strategy, additional rounds of mixing and novel genotype calling approaches, we developed a bread wheat eight parent MAGIC population made up of more than 3000 fully genotyped recombinant inbred lines derived from 2151 distinct crosses, and achieved a dense genetic map covering the complete genome. Further rounds of inter-crossing led to increased recombination in inbred lines, as expected. The comprehensive and novel approaches taken in the development and analysis of this population provide a platform for genetic discovery in bread wheat. We identify previously unreported structural variation highlighted by segregation distortion, along with the identification of epistatic allelic interactions between specific founders. We demonstrate the ability to conduct high resolution QTL mapping using the number of recombination events as a trait, and identify several significant QTLs explaining greater than 50% of the variance.ConclusionsWe report on a novel and effective resource for genomic and trait exploration in hexaploid wheat, that can be used to detect small genetic effects and epistatic interactions due to the high level of recombination and large number of lines. The interactions and genetic effects identified provide a basis for ongoing research to understand the basis of allelic frequencies across the genome, particularly where economically important loci are involved.

Mapping Quantitative Traits Loci for Seed Glucosinolate Content inBrassica napusUsing High-density SNP Map

2014 ◽  
Vol 40 (8) ◽  
pp. 1386 ◽  
Author(s):  
Hong-Ju JIAN ◽  
Li-Juan WEI ◽  
Jia-Na LI ◽  
Xin-Fu XU ◽  
Li CHEN ◽  
...  
Keyword(s):  
Quantitative Traits ◽  
High Density ◽  
Glucosinolate Content ◽  
Snp Map
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