Major QTL with pleiotropic effects controlling time of leaf budburst and flowering-related traits in walnut (Juglans regia L.)

Abstract Breeding studies in walnut (Juglans regia L.) are usually time consuming due to the long juvenile period and therefore, this study aimed to determine markers associated with time of leaf budburst and flowering-related traits by performing a genome-wide association study (GWAS). We investigated genotypic variation and its association with time of leaf budburst and flowering-related traits in 188 walnut accessions. Phenotypic data was obtained from 13 different traits during 3 consecutive years. We used DArT-seq for genotyping with a total of 33,519 (14,761 SNP and 18,758 DArT) markers for genome-wide associations to identify marker underlying these traits. Significant correlations were determined among the 13 different traits. Linkage disequilibrium decayed very quickly in walnut in comparison with other plants. Sixteen quantitative trait loci (QTL) with major effects (R2 between 0.08 and 0.23) were found to be associated with a minimum of two phenotypic traits each. Of these QTL, QTL05 had the maximum number of associated traits (seven). Our study is GWAS for time of leaf budburst and flowering-related traits in Juglans regia L. and has a strong potential to efficiently implement the identified QTL in walnut breeding programs.

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Genome-Wide Analyses Identifies Known and New Markers Responsible of Chicken Plumage Color

Animals ◽

10.3390/ani10030493 ◽

2020 ◽

Vol 10 (3) ◽

pp. 493

Author(s):

Salvatore Mastrangelo ◽

Filippo Cendron ◽

Gianluca Sottile ◽

Giovanni Niero ◽

Baldassare Portolano ◽

...

Keyword(s):

Genome Wide Association Study ◽

Snp Array ◽

Fixation Index ◽

Phenotypic Traits ◽

Plumage Color ◽

Phenotypic Marker ◽

Genome Wide ◽

A Genome ◽

The Difference ◽

Genomic Regions

Through the development of the high-throughput genotyping arrays, molecular markers and genes related to phenotypic traits have been identified in livestock species. In poultry, plumage color is an important qualitative trait that can be used as phenotypic marker for breed identification. In order to assess sources of genetic variation related to the Polverara chicken breed plumage colour (black vs. white), we carried out a genome-wide association study (GWAS) and a genome-wide fixation index (FST) scan to uncover the genomic regions involved. A total of 37 animals (17 white and 20 black) were genotyped with the Affymetrix 600 K Chicken single nucleotide polymorphism (SNP) Array. The combination of results from GWAS and FST revealed a total of 40 significant markers distributed on GGA 01, 03, 08, 12 and 21, and located within or near known genes. In addition to the well-known TYR, other candidate genes have been identified in this study, such as GRM5, RAB38 and NOTCH2. All these genes could explain the difference between the two Polverara breeds. Therefore, this study provides the basis for further investigation of the genetic mechanisms involved in plumage color in chicken.

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Genetic analysis of sucrose concentration in soybean seeds using a historical soybean genomic panel

10.21203/rs.3.rs-158915/v1 ◽

2021 ◽

Author(s):

Alexandra Ficht ◽

Robert W. Bruce ◽

Davoud Torkamaneh ◽

Christopher Grainger ◽

Milad Eskandari ◽

...

Keyword(s):

Genetic Variability ◽

Genome Wide Association Study ◽

Sucrose Concentration ◽

Soybean Seed ◽

Breeding Programs ◽

Snp Data ◽

Genome Wide ◽

A Genome ◽

Important Trait ◽

Genotype By Sequencing

Abstract Soybean (Glycine max (L.) Merr) is a crop of global importance for both human and animal consumption, which was domesticated in China more than 6000 years ago. A concern about losing genetic diversity as a result of decades of breeding has been expressed by soybean researchers. In order to develop new cultivars, it is critical for breeders to understand the genetic variability present for traits of interest in their program germplasm. Sucrose concentration is becoming an increasingly important trait for the production of soy-food products. The objective of this study was to use a genome-wide association study (GWAS) to identify putative QTL for sucrose concentration in soybean seed. A GWAS panel consisting of 266 historic and current soybean accessions was genotyped with 76k genotype-by-sequencing (GBS) SNP data and phenotyped in four field locations in Ontario (Canada) from 2015 to 2017. Seven putative QTL were identified on chromosomes 1, 6, 8, 9, 10, 13 and 14. A key gene related to sucrose synthase (Glyma.06g182700) was found to be associated with the QTL found on chromosome 6. This information will facilitate efforts to increase the available genetic variability for sucrose concentration in soybean breeding programs and develop new and improved high-sucrose soybean cultivars suitable for the soy-food industry.

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Genetics of Germination and Seedling Traits under Drought Stress in a MAGIC Population of Maize

Plants ◽

10.3390/plants10091786 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1786

Author(s):

Soumeya Rida ◽

Oula Maafi ◽

Ana López-Malvar ◽

Pedro Revilla ◽

Meriem Riache ◽

...

Keyword(s):

Drought Tolerance ◽

Genome Wide Association Study ◽

Genetic Regulation ◽

Breeding Programs ◽

Seedling Traits ◽

Genome Wide ◽

A Genome ◽

Positive Correlations ◽

Genomic Regions ◽

Magic Population

Drought is one of the most detrimental abiotic stresses hampering seed germination, development, and productivity. Maize is more sensitive to drought than other cereals, especially at seedling stage. Our objective was to study genetic regulation of drought tolerance at germination and during seedling growth in maize. We evaluated 420 RIL with their parents from a multi-parent advanced generation inter-cross (MAGIC) population with PEG-induced drought at germination and seedling establishment. A genome-wide association study (GWAS) was carried out to identify genomic regions associated with drought tolerance. GWAS identified 28 and 16 SNPs significantly associated with germination and seedling traits under stress and well-watered conditions, respectively. Among the SNPs detected, two SNPs had significant associations with several traits with high positive correlations, suggesting a pleiotropic genetic control. Other SNPs were located in regions that harbored major QTLs in previous studies, and co-located with QTLs for cold tolerance previously published for this MAGIC population. The genomic regions comprised several candidate genes related to stresses and plant development. These included numerous drought-responsive genes and transcription factors implicated in germination, seedling traits, and drought tolerance. The current analyses provide information and tools for subsequent studies and breeding programs for improving drought tolerance.

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Genome-Wide Association Study of Root Mealiness and Other Texture-Associated Traits in Cassava

Frontiers in Plant Science ◽

10.3389/fpls.2021.770434 ◽

2021 ◽

Vol 12 ◽

Author(s):

Kelechi Uchendu ◽

Damian Ndubuisi Njoku ◽

Agre Paterne ◽

Ismail Yusuf Rabbi ◽

Daniel Dzidzienyo ◽

...

Keyword(s):

Candidate Genes ◽

Genome Wide Association Study ◽

Genome Wide Association ◽

Nucleotide Polymorphisms ◽

Phenotypic Data ◽

Genome Wide ◽

A Genome ◽

Breeding Programmes ◽

Vegetables And Fruits ◽

Genomic Regions

Cassava breeders have made significant progress in developing new genotypes with improved agronomic characteristics such as improved root yield and resistance against biotic and abiotic stresses. However, these new and improved cassava (Manihot esculenta Crantz) varieties in cultivation in Nigeria have undergone little or no improvement in their culinary qualities; hence, there is a paucity of genetic information regarding the texture of boiled cassava, particularly with respect to its mealiness, the principal sensory quality attribute of boiled cassava roots. The current study aimed at identifying genomic regions and polymorphisms associated with natural variation for root mealiness and other texture-related attributes of boiled cassava roots, which includes fibre, adhesiveness (ADH), taste, aroma, colour, and firmness. We performed a genome-wide association (GWAS) analysis using phenotypic data from a panel of 142 accessions obtained from the National Root Crops Research Institute (NRCRI), Umudike, Nigeria, and a set of 59,792 high-quality single nucleotide polymorphisms (SNPs) distributed across the cassava genome. Through genome-wide association mapping, we identified 80 SNPs that were significantly associated with root mealiness, fibre, adhesiveness, taste, aroma, colour and firmness on chromosomes 1, 4, 5, 6, 10, 13, 17 and 18. We also identified relevant candidate genes that are co-located with peak SNPs linked to these traits in M. esculenta. A survey of the cassava reference genome v6.1 positioned the SNPs on chromosome 13 in the vicinity of Manes.13G026900, a gene recognized as being responsible for cell adhesion and for the mealiness or crispness of vegetables and fruits, and also known to play an important role in cooked potato texture. This study provides the first insights into understanding the underlying genetic basis of boiled cassava root texture. After validation, the markers and candidate genes identified in this novel work could provide important genomic resources for use in marker-assisted selection (MAS) and genomic selection (GS) to accelerate genetic improvement of root mealiness and other culinary qualities in cassava breeding programmes in West Africa, especially in Nigeria, where the consumption of boiled and pounded cassava is low.

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Approximate conditional phenotype analysis based on genome wide association summary statistics

Scientific Reports ◽

10.1038/s41598-021-82000-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Peitao Wu ◽

Biqi Wang ◽

Steven A. Lubitz ◽

Emelia J. Benjamin ◽

James B. Meigs ◽

...

Keyword(s):

Large Scale ◽

Genome Wide Association Study ◽

Genome Wide Association ◽

Summary Statistics ◽

Phenotypic Data ◽

Individual Level ◽

Genome Wide ◽

Level Data ◽

A Genome ◽

Phenotype Analysis

AbstractBecause single genetic variants may have pleiotropic effects, one trait can be a confounder in a genome-wide association study (GWAS) that aims to identify loci associated with another trait. A typical approach to address this issue is to perform an additional analysis adjusting for the confounder. However, obtaining conditional results can be time-consuming. We propose an approximate conditional phenotype analysis based on GWAS summary statistics, the covariance between outcome and confounder, and the variant minor allele frequency (MAF). GWAS summary statistics and MAF are taken from GWAS meta-analysis results while the traits covariance may be estimated by two strategies: (i) estimates from a subset of the phenotypic data; or (ii) estimates from published studies. We compare our two strategies with estimates using individual level data from the full GWAS sample (gold standard). A simulation study for both binary and continuous traits demonstrates that our approximate approach is accurate. We apply our method to the Framingham Heart Study (FHS) GWAS and to large-scale cardiometabolic GWAS results. We observed a high consistency of genetic effect size estimates between our method and individual level data analysis. Our approach leads to an efficient way to perform approximate conditional analysis using large-scale GWAS summary statistics.

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Genome-Wide Association Study Reveals Candidate Genes Involved in Fruit Trait Variation in Persian Walnut (Juglans regia L.)

Frontiers in Plant Science ◽

10.3389/fpls.2020.607213 ◽

2021 ◽

Vol 11 ◽

Author(s):

Anthony Bernard ◽

Julie Crabier ◽

Armel S. L. Donkpegan ◽

Annarita Marrano ◽

Fabrice Lheureux ◽

...

Keyword(s):

Association Study ◽

Candidate Genes ◽

Fruit Quality ◽

Genome Wide Association Study ◽

Juglans Regia ◽

Snp Array ◽

Germplasm Collection ◽

Genome Wide Association ◽

Genome Wide ◽

A Genome

Elucidating the genetic determinants of fruit quality traits in walnut is essential to breed new cultivars meeting the producers and consumers’ needs. We conducted a genome-wide association study (GWAS) using multi-locus models in a panel of 170 accessions of Juglans regia from the INRAE walnut germplasm collection, previously genotyped using the AxiomTMJ. regia 700K SNP array. We phenotyped the panel for 25 fruit traits related to morphometrics, shape, volume, weight, ease of cracking, and nutritional composition. We found more than 60 marker-trait associations (MTAs), including a highly significant SNP associated with nut face diameter, nut volume and kernel volume on chromosome 14, and 5 additional associations were detected for walnut weight. We proposed several candidate genes involved in nut characteristics, such as a gene coding for a beta-galactosidase linked to several size-related traits and known to be involved in fruit development in other species. We also confirmed associations on chromosomes 5 and 11 with nut suture strength, recently reported by the University of California, Davis. Our results enhance knowledge of the genetic control of important agronomic traits related to fruit quality in walnut, and pave the way for the development of molecular markers for future assisted selection.

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The genetic basis of the human-cannabis relationship

10.1101/287938 ◽

2018 ◽

Author(s):

Philippe Henry

Keyword(s):

Genetic Basis ◽

Genome Wide Association Study ◽

Diagnostic Process ◽

Nucleotide Polymorphisms ◽

Phenotypic Data ◽

Single Nucleotide ◽

Web Based ◽

Genome Wide ◽

A Genome ◽

Shed Light

AbstractCannabis can elicit various reactions in different consumers. In order to shed light on the mechanisms underlying the human-cannabis relationship, we begin to investigate the genetic basis of this differential response. The web-based platform OpenSNP was used to collect selfreported genetic and phenotypic data. Participants either reported a positively or negative affinity to cannabis. A total of 26 individuals were retained, 10 of which indicated several negative responses and the remaining 16 indicating strong affinity for Cannabis. A total of 325’895 single nucleotide polymorphisms (SNPs) were retained. The software TASSEL 5 was used to run a genome-wide association study (GWAS), with a generalized liner model (GLM) and1000 permutations. The analysis yielded a set of 45 SNPs that were significantly associated with the reported affinity to cannabis, including one strong outlier found in the MYO16 gene. A diagnostic process is proposed by which individuals can be assessed for their affinity to cannabis. We believe this type of tool may be helpful in alleviating some of the stigma associated with cannabis use in individuals sensitive to THC and other cannabis constituents such as myrcene, which may potentiate negative responses.

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Enhanced NRT1.1/NPF6.3 expression in shoots improves growth under nitrogen deficiency stress in Arabidopsis

Communications Biology ◽

10.1038/s42003-021-01775-1 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yasuhito Sakuraba ◽

Chaganzhana ◽

Atsushi Mabuchi ◽

Koh Iba ◽

Shuichi Yanagisawa

Keyword(s):

Plant Growth ◽

Nitrate Uptake ◽

Genome Wide Association Study ◽

Nitrogen Deficiency ◽

Breeding Programs ◽

Promoter Sequences ◽

Genome Wide ◽

A Genome ◽

N Deficiency ◽

Low Nitrogen

AbstractIdentification of genes and their alleles capable of improving plant growth under low nitrogen (N) conditions is key for developing sustainable agriculture. Here, we show that a genome-wide association study using Arabidopsis thaliana accessions suggested an association between different magnitudes of N deficiency responses and diversity in NRT1.1/NPF6.3 that encodes a dual-affinity nitrate transporter involved in nitrate uptake by roots. Various analyses using accessions exhibiting reduced N deficiency responses revealed that enhanced NRT1.1 expression in shoots rather than in roots is responsible for better growth of Arabidopsis seedlings under N deficient conditions. Furthermore, polymorphisms that increased NRT1.1 promoter activity were identified in the NRT1.1 promoter sequences of the accessions analyzed. Hence, our data indicated that polymorphism-dependent activation of the NRT1.1 promoter in shoots could serve as a tool in molecular breeding programs for improving plant growth in low N environments.

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Genome-wide association study on metabolite accumulation in a wild barley NAM population reveals natural variation in sugar metabolism

PLoS ONE ◽

10.1371/journal.pone.0246510 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0246510

Author(s):

Mathias Ruben Gemmer ◽

Chris Richter ◽

Thomas Schmutzer ◽

Manish L. Raorane ◽

Björn Junker ◽

...

Keyword(s):

Association Study ◽

Stress Responses ◽

Genome Wide Association Study ◽

Wild Barley ◽

Genome Wide Association ◽

Phenotypic Traits ◽

Genetic Components ◽

Genome Wide ◽

A Genome ◽

Metabolite Accumulation

Metabolites play a key role in plants as they are routing plant developmental processes and are involved in biotic and abiotic stress responses. Their analysis can offer important information on the underlying processes. Regarding plant breeding, metabolite concentrations can be used as biomarkers instead of or in addition to genetic markers to predict important phenotypic traits (metabolic prediction). In this study, we applied a genome-wide association study (GWAS) in a wild barley nested association mapping (NAM) population to identify metabolic quantitative trait loci (mQTL). A set of approximately 130 metabolites, measured at early and late sampling dates, was analysed. For four metabolites from the early and six metabolites from the late sampling date significant mQTL (grouped as 19 mQTL for the early and 25 mQTL for the late sampling date) were found. Interestingly, all of those metabolites could be classified as sugars. Sugars are known to be involved in signalling, plant growth and plant development. Sugar-related genes, encoding mainly sugar transporters, have been identified as candidate genes for most of the mQTL. Moreover, several of them co-localized with known flowering time genes like Ppd-H1, HvELF3, Vrn-H1, Vrn-H2 and Vrn-H3, hinting on the known role of sugars in flowering. Furthermore, numerous disease resistance-related genes were detected, pointing to the signalling function of sugars in plant resistance. An mQTL on chromosome 1H in the region of 13 Mbp to 20 Mbp stood out, that alone explained up to 65% of the phenotypic variation of a single metabolite. Analysis of family-specific effects within the diverse NAM population showed the available natural genetic variation regarding sugar metabolites due to different wild alleles. The study represents a step towards a better understanding of the genetic components of metabolite accumulation, especially sugars, thereby linking them to biological functions in barley.

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Genome-wide association analysis reveals new insights into the genetic architecture of defensive, agro-morphological and quality-related traits in cassava

10.1101/2020.04.25.061440 ◽

2020 ◽

Author(s):

Ismail Yusuf Rabbi ◽

Siraj Ismail Kayondo ◽

Guillaume Bauchet ◽

Muyideen Yusuf ◽

Cynthia Idhigu Aghogho ◽

...

Keyword(s):

Candidate Genes ◽

Genome Wide Association Study ◽

Genome Wide Association ◽

Carotenoid Content ◽

Cassava Mosaic Disease ◽

International Institute ◽

Dry Matter Content ◽

Breeding Programs ◽

Genome Wide ◽

A Genome

AbstractCassava (Manihot esculenta) is one of the most important starchy root crops in the tropics due to its adaptation to marginal environments. Genetic progress in this clonally propagated crop can be accelerated through the discovery of markers and candidate genes that could be used in cassava breeding programs. We carried out a genome-wide association study (GWAS) using a panel of 5,310 clones developed at the International Institute of Tropical Agriculture - Nigeria. The population was genotyped at more than 100,000 SNP markers via genotyping-by-sequencing (GBS). Genomic regions underlying genetic variation for 14 traits classified broadly into four categories: biotic stress (cassava mosaic disease and cassava green mite severity); quality (dry matter content and carotenoid content) and plant agronomy (harvest index and plant type). We also included several agro-morphological traits related to leaves, stems and roots with high heritability. In total, 41 significant associations were uncovered. While some of the identified loci matched with those previously reported, we present additional association signals for the traits. We provide a catalogue of favourable alleles at the most significant SNP for each trait-locus combination and candidate genes occurring within the GWAS hits. These resources provide a foundation for the development of markers that could be used in cassava breeding programs and candidate genes for functional validation.

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