scholarly journals Dissection of the genetic basis of oil content in Chinese peanut cultivars through association mapping

2020 ◽  
Author(s):  
Nian Liu ◽  
Li Huang ◽  
Weigang Chen ◽  
Bei Wu ◽  
Manish K. Pandey ◽  
...  
Keyword(s):  
Association Mapping ◽  
Ssr Markers ◽  
Oil Content ◽  
Genetic Basis ◽  
Principal Component ◽  
Primary Sources ◽  
Phenotypic Variance ◽  
Mapping Panel ◽  
Stable Association ◽  
Faster Development

Abstract Background: Peanut is one of the primary sources for vegetable oil worldwide, and enhancing oil content is the main objective in several peanut breeding programs of the world. Tightly linked markers are required for faster development of high oil content peanut varieties through genomics-assisted breeding (GAB), and association mapping is one of the promising approaches for discovery of such associated markers. Results: An association mapping panel consisting of 292 peanut varieties extensively distributed in China was phenotyped for oil content and genotyped with 583 polymorphic SSR markers. These markers amplified 3663 alleles with an average of 6.28 alleles per locus. The structure, phylogenetic relationship, and principal component analysis (PCA) indicated two subgroups majorly differentiating based on geographic regions. Genome-wide association analysis identified 12 associated markers including one (AGGS1014_2) highly stable association controlling up to 9.94% phenotypic variance explained (PVE) across multiple environments. Interestingly, the frequency of the favorable alleles for 12 associated markers showed a geographic difference. Two associated markers (AGGS1014_2 and AHGS0798) with 6.90-9.94% PVE were verified to enhance oil content in an independent RIL population and also indicated selection during the breeding program. Conclusion: This study provided insights into the genetic basis of oil content in peanut and verified highly associated two SSR markers to facilitate marker-assisted selection for developing high-oil content breeding peanut varieties.

scholarly journals Dissection of the genetic basis of oil content in Chinese peanut cultivars by association mapping

2020 ◽  
Author(s):  
Nian Liu ◽  
Li Huang ◽  
Weigang Chen ◽  
Bei Wu ◽  
Manish K. Pandey ◽  
...  
Keyword(s):  
Association Mapping ◽  
Ssr Markers ◽  
Oil Content ◽  
Genetic Basis ◽  
Primary Sources ◽  
Phenotypic Variance ◽  
Phenotypic Data ◽  
Mapping Panel ◽  
Genome Wide ◽  
Stable Association

Abstract Background Peanut is one of the primary sources for vegetable oil worldwide, and enhancing oil content is the main objective in these peanut breeding programs. Linked markers for oil content is required for use in genomics-assisted breeding (GAB), and association mapping is one of the promising approaches for discovery of associated markers. Results An association mapping panel consisting of 292 peanut varieties extensively distributed in China were phenotyped for oil content and genotyped with 583 polymorphic SSR markers. These markers amplified 3663 alleles with an average of 6.28 alleles per locus. The results of structure, phylogenetic relationship, and PCA analyses indicated two subgroups majorly differentiating based on geographic regions. Genome-wide association analysis using genetic and phenotypic data identified 12 associated markers including one (AGGS1014_2) highly stable association controlling up to 9.94% phenotypic variance explained (PVE) across multiple environments. Interestingly, the frequency of the favorable alleles for 12 associated markers showed a geographic difference. Two associated markers AGGS1014_2 and AHGS0798 with 6.90-9.94% PVE were verified to enhance oil content in an independent RIL population. The combined genotypes of AGGS1014_2 and AHGS0798 appeared to experience selection during the breeding program. Conclusion This study provided insights into the genetic basis of oil content in peanut and verified that two SSR markers were highly associated with oil content. Our results could facilitate marker-assisted selection for high-oil content breeding.

scholarly journals Genome-wide association mapping in a wild avian population identifies a link between genetic and phenotypic variation in a life-history trait

2015 ◽  
Vol 282 (1806) ◽  
pp. 20150156 ◽  
Author(s):  
Arild Husby ◽  
Takeshi Kawakami ◽  
Lars Rönnegård ◽  
Linnéa Smeds ◽  
Hans Ellegren ◽  
...  
Keyword(s):  
Life History ◽  
Association Mapping ◽  
Genetic Basis ◽  
Snp Array ◽  
Genome Wide Association ◽  
Life History Trait ◽  
Lifetime Reproductive Success ◽  
Phenotypic Variance ◽  
Sexual Antagonism ◽  
Genome Wide

Understanding the genetic basis of traits involved in adaptation is a major challenge in evolutionary biology but remains poorly understood. Here, we use genome-wide association mapping using a custom 50 k single nucleotide polymorphism (SNP) array in a natural population of collared flycatchers to examine the genetic basis of clutch size, an important life-history trait in many animal species. We found evidence for an association on chromosome 18 where one SNP significant at the genome-wide level explained 3.9% of the phenotypic variance. We also detected two suggestive quantitative trait loci (QTLs) on chromosomes 9 and 26. Fitness differences among genotypes were generally weak and not significant, although there was some indication of a sex-by-genotype interaction for lifetime reproductive success at the suggestive QTL on chromosome 26. This implies that sexual antagonism may play a role in maintaining genetic variation at this QTL. Our findings provide candidate regions for a classic avian life-history trait that will be useful for future studies examining the molecular and cellular function of, as well as evolutionary mechanisms operating at, these loci.

Identification of QTL for seed coat colour and oil content in Brassica napus by association mapping using SSR markers

2015 ◽  
Vol 95 (2) ◽  
pp. 387-395 ◽  
Author(s):  
Cunmin Qu ◽  
Maen Hasan ◽  
Kun Lu ◽  
Liezhao Liu ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Association Mapping ◽  
Ssr Markers ◽  
Seed Coat ◽  
Oil Content ◽  
Coat Colour ◽  
Seed Coat Colour ◽  
Functional Polymorphisms ◽  
Genome Wide ◽  
Major Qtl

Qu, C., Hasan, M., Lu, K., Liu, L., Zhang, K., Fu, F., Wang, M., Liu, S., Bu, H., Wang, R., Xu, X., Chen, L. and Li, J. 2015. Identification of QTL for seed coat colour and oil content in Brassica napus by association mapping using SSR markers. Can. J. Plant Sci. 95: 387–395. Association mapping identifies quantitative trait loci (QTL) based on the strength of linkage disequilibrium (LD) between markers and functional polymorphisms across a set of diverse germplasms. In this study, we used association mapping to detect QTL and genome-wide simple sequence repeat (SSR) markers linked to seed coat colour and oil content in a population of 217 oilseed rape (Brassica napus L.) accessions. We corrected for the population structure of B. napus using 389 genome-wide SSR markers. In total, 25 and 11 SSR markers linked to seed coat colour and oil content were detected, respectively, and these two sets of markers were in different linkage groups. Nine of these markers for seed coat colour spanned the major QTL region for seed coat colour, and been mapped to chromosome A9. Six of these markers showed high levels of association with both seed coat colour and oil content, and markers H081N08.8 and KS20291 were mapped to the major QTL region for seed coat colour on chromosome A9. Another marker, CB10364, was in high LD with all determined seed coat colour and oil content traits, and was mapped to the co-localized QTL region for them on chromosome A8. These data indicate that seed coat colour was found to be an important contributor to seed oil content. Further, we show that association mapping using a heterogeneous set of genotypes is a suitable approach for complementing and enhancing previously obtained QTL information for marker-assisted selection.

scholarly journals Polygenicity and epistasis underlie fitness-proximal traits in the Caenorhabditis elegans multiparental experimental evolution (CeMEE) panel

2017 ◽  
Author(s):  
Luke M. Noble ◽  
Ivo Chelo ◽  
Thiago Guzella ◽  
Bruno Afonso ◽  
David D. Riccardi ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Experimental Evolution ◽  
Complex Traits ◽  
Genetic Basis ◽  
Natural Populations ◽  
Phenotypic Variance ◽  
Nucleotide Polymorphisms ◽  
C Elegans ◽  
Mapping Panel ◽  
Trait Locus

ABSTRACTUnderstanding the genetic basis of complex traits remains a major challenge in biology. Polygenicity, phenotypic plasticity and epistasis contribute to phenotypic variance in ways that are rarely clear. This uncertainty is problematic for estimating heritability, for predicting individual phenotypes from genomic data, and for parameterizing models of phenotypic evolution. Here we report a recombinant inbred line (RIL) quantitative trait locus (QTL) mapping panel for the hermaphroditic nematode Caenorhabditis elegans, the C. elegans multiparental experimental evolution (CeMEE) panel. The CeMEE panel, comprising 507 RILs, was created by hybridization of 16 wild isolates, experimental evolution at moderate population sizes and predominant outcrossing for 140-190 generations, and inbreeding by selfing for 13-16 generations. The panel contains 22% of single nucleotide polymorphisms known to segregate in natural populations, and complements existing mapping resources for C. elegans by providing high nucleotide diversity across >95% of the genome. We apply it to study the genetic basis of two fitness components, fertility and hermaphrodite body size at time of reproduction, with high broad sense heritability in the CeMEE. While simulations show we should detect common alleles with additive effects as small as 5%, at gene-level resolution, the genetic architectures of these traits does not feature such alleles. We instead find that a significant fraction of trait variance, particularly for fertility, can be explained by sign epistasis with weak main effects. In congruence, phenotype prediction, while generally poor (r2 < 10%), requires modeling epistasis for optimal accuracy, with most variance attributed to the highly recombinant, rapidly evolving chromosome arms.

scholarly journals Combination of Linkage Mapping, GWAS, and GP to Dissect the Genetic Basis of Common Rust Resistance in Tropical Maize Germplasm

2020 ◽  
Vol 21 (18) ◽  
pp. 6518
Author(s):  
Maguta Kibe ◽  
Christine Nyaga ◽  
Sudha K. Nair ◽  
Yoseph Beyene ◽  
Biswanath Das ◽  
...  
Keyword(s):  
Association Mapping ◽  
Linkage Mapping ◽  
Genetic Basis ◽  
Chromosome 8 ◽  
High Yield ◽  
Phenotypic Variance ◽  
Tropical Maize ◽  
Training Set ◽  
Association Panel ◽  
Gxe Interaction

Common rust (CR) caused by Puccina sorghi is one of the destructive fungal foliar diseases of maize and has been reported to cause moderate to high yield losses. Providing CR resistant germplasm has the potential to increase yields. To dissect the genetic architecture of CR resistance in maize, association mapping, in conjunction with linkage mapping, joint linkage association mapping (JLAM), and genomic prediction (GP) was conducted on an association-mapping panel and five F3 biparental populations using genotyping-by-sequencing (GBS) single-nucleotide polymorphisms (SNPs). Analysis of variance for the biparental populations and the association panel showed significant genotypic and genotype x environment (GXE) interaction variances except for GXE of Pop4. Heritability (h2) estimates were moderate with 0.37–0.45 for the individual F3 populations, 0.45 across five populations and 0.65 for the association panel. Genome-wide association study (GWAS) analyses revealed 14 significant marker-trait associations which individually explained 6–10% of the total phenotypic variances. Individual population-based linkage analysis revealed 26 QTLs associated with CR resistance and together explained 14–40% of the total phenotypic variances. Linkage mapping revealed seven QTLs in pop1, nine QTL in pop2, four QTL in pop3, five QTL in pop4, and one QTL in pop5, distributed on all chromosomes except chromosome 10. JLAM for the 921 F3 families from five populations detected 18 QTLs distributed in all chromosomes except on chromosome 8. These QTLs individually explained 0.3 to 3.1% and together explained 45% of the total phenotypic variance. Among the 18 QTL detected through JLAM, six QTLs, qCR1-78, qCR1-227, qCR3-172, qCR3-186, qCR4-171, and qCR7-137 were also detected in linkage mapping. GP within population revealed low to moderate correlations with a range from 0.19 to 0.51. Prediction correlation was high with r = 0.78 for combined analysis of the five F3 populations. Prediction of biparental populations by using association panel as training set reveals positive correlations ranging from 0.05 to 0.22, which encourages to develop an independent but related population as a training set which can be used to predict diverse but related populations. The findings of this study provide valuable information on understanding the genetic basis of CR resistance and the obtained information can be used for developing functional molecular markers for marker-assisted selection and for implementing GP to improve CR resistance in tropical maize.

scholarly journals Dissection of the genetic basis of oil content in Chinese peanut cultivars through association mapping

BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Nian Liu ◽  
Li Huang ◽  
Weigang Chen ◽  
Bei Wu ◽  
Manish K. Pandey ◽  
...  
Keyword(s):  
Association Mapping ◽  
Oil Content ◽  
Genetic Basis ◽  
Peanut Cultivars

Association mapping and favourable allele exploration for plant architecture traits in upland cotton (Gossypium hirsutum L.) accessions

2015 ◽  
Vol 154 (4) ◽  
pp. 567-583 ◽  
Author(s):  
C. Q. LI ◽  
N. J. AI ◽  
Y. J. ZHU ◽  
Y. Q. WANG ◽  
X. D. CHEN ◽  
...  
Keyword(s):  
Gossypium Hirsutum ◽  
Association Mapping ◽  
Ssr Markers ◽  
Complex Traits ◽  
Upland Cotton ◽  
Plant Architecture ◽  
Final Analysis ◽  
Mixed Linear Model ◽  
Mapping Panel ◽  
Breeding Programmes

SUMMARYAssociation mapping based on linkage disequilibrium (LD) is a promising tool to identify genes responsible for quantitative variations underlying complex traits. The present paper presents an association mapping panel consisting of 172 upland cotton (Gossypium hirsutum L.) accessions. The panel was phenotyped for five cotton plant architecture traits across multiple environments and genotyped using 386 simple sequence repeat (SSR) markers. Of these markers, 101 polymorphic SSR markers were used in the final analysis. There were abundant phenotypic variations within this germplasm panel and a total of 267 alleles ranging from two to seven per locus were identified in all collections. The threshold of LD decay was set to r2 = 0·1 and 0·2, and the genome-wide LD extended up to about 13–14 and 6–7 cM, respectively, providing the potential for association mapping of agronomically important traits in upland cotton. A total of 66 marker–trait associations were detected based on a mixed linear model, of which 35 were found in more than one environment. The favourable alleles from 35 marker loci can be used in marker-assisted selection of target traits. Both the synergistic alleles and the negative alleles for some traits, especially plant height and fruit branch angle, can be utilized in plant architecture breeding programmes according to specific breeding objectives.

scholarly journals Identification of Quantitative Trait Loci for Related Traits of Stalk Lodging Resistance Using Genome-wide Association Studies in Maize (Zea mays L.)

2021 ◽  
Author(s):  
Lifen Wu ◽  
Yunxiao Zheng ◽  
Fuchao Jiao ◽  
Ming Wang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Zea Mays ◽  
Quantitative Trait Loci ◽  
Association Mapping ◽  
Quantitative Trait ◽  
Genetic Basis ◽  
Genome Wide Association ◽  
Lodging Resistance ◽  
Mapping Panel ◽  
Genome Wide ◽  
Stalk Lodging

Abstract Background: Stalk lodging is one of the main factors affecting maize (Zea mays L.) yield and limiting mechanized harvesting. Developing maize varieties with high stalk lodging resistance requires exploring the genetic basis of lodging resistance-associated agronomic traits. Stalk strength is an important indicator to evaluate maize lodging and can be evaluated by measuring stalk rind penetrometer resistance (RPR) and stalk buckling strength (SBS). And morphological traits of the stalk for the third internodes length (TIL), fourth internode length (FIL), third internode diameter (TID), and the fourth internode diameter (FID) traits are associated with stalk lodging resistance.Results: In this study, 248 genome-wide association study (GWAS) panel with 83,057 single nucleotide polymorphisms (SNPs) were used to detect the quantitative trait loci (QTLs) for six stalk lodging resistance-related traits. The heritability of all traits ranged from 0.59 to 0.72 in the association mapping panel. A total of 85 significant SNPs were identified for the association mapping panel using best linear unbiased prediction (BLUP) values of all traits. Additionally, five candidate genes were associated with stalk strength traits, which were either directly or indirectly associated with cell wall components. Conclusions: These findings contribute to our understanding of the genetic basis of maize stalk lodging and provide valuable theoretical guidance for lodging resistance in maize breeding in the future.

Identification of SSR Markers Linked to Oil Content in Peanut (Arachis hypogaea L.) through RIL Population and Natural Population

2012 ◽  
Vol 37 (11) ◽  
pp. 1967-1974 ◽  
Author(s):  
Li HUANG ◽  
Xin-Yan ZHAO ◽  
Wen-Hua ZHANG ◽  
Zhi-Ming FAN ◽  
Xiao-Ping REN ◽  
...  
Keyword(s):  
Natural Population ◽  
Arachis Hypogaea ◽  
Ssr Markers ◽  
Oil Content ◽  
Ril Population

Quantitative Trait Loci for Susceptibility to Tapeworm Infection in the Red Flour Beetle

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1307-1315
Author(s):  
Daibin Zhong ◽  
Aditi Pai ◽  
Guiyun Yan
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Genetic Basis ◽  
Life Cycles ◽  
Red Flour Beetle ◽  
Phenotypic Variance ◽  
Flour Beetle ◽  
Trait Loci ◽  
Host Ecology ◽  
Tapeworm Infection

Abstract Parasites have profound effects on host ecology and evolution, and the effects of parasites on host ecology are often influenced by the magnitude of host susceptibility to parasites. Many parasites have complex life cycles that require intermediate hosts for their transmission, but little is known about the genetic basis of the intermediate host's susceptibility to these parasites. This study examined the genetic basis of susceptibility to a tapeworm (Hymenolepis diminuta) in the red flour beetle (Tribolium castaneum) that serves as an intermediate host in its transmission. Quantitative trait loci (QTL) mapping experiments were conducted with two independent segregating populations using amplified fragment length polymorphism (AFLP) markers and randomly amplified polymorphic DNA (RAPD) markers. A total of five QTL that significantly affected beetle susceptibility were identified in the two reciprocal crosses. Two common QTL on linkage groups 3 and 6 were identified in both crosses with similar effects on the phenotype, and three QTL were unique to each cross. In one cross, the three main QTL accounted for 29% of the total phenotypic variance and digenic epistasis explained 39% of the variance. In the second cross, the four main QTL explained 62% of the variance and digenic epistasis accounted for only 5% of the variance. The actions of these QTL were either overdominance or underdominance. Our results suggest that the polygenic nature of beetle susceptibility to the parasites and epistasis are important genetic mechanisms for the maintenance of variation within or among beetle strains in susceptibility to tapeworm infection.

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