scholarly journals Genome-Wide Association Mapping for Stomata and Yield Indices in Bread Wheat under Water Limited Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1646
Author(s):  
Hafiz Ghulam Muhu-Din Ahmed ◽  
Muhammad Nouman Iqbal ◽  
Muhammad Arslan Iqbal ◽  
Yawen Zeng ◽  
Aziz Ullah ◽  
...  
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Significant Snps ◽  
Water Shortage ◽  
Genome Wide Association ◽  
Yield Potential ◽  
Strong Positive Correlation ◽  
Leaf Venation ◽  
Genome Wide ◽  
Stomata Size

Genome-wide association study (GWAS) was performed for stomata- and yield-related attributes with high-density Illumina 90 K Infinium SNP (single nucleotide polymorphism) array in bread wheat to determine genetic potential of germplasm for scarce water resources with sustainable yield potential. Major yield and stomata attributes were phenotyped on a panel of Pakistani and foreign accessions grown in non-stressed and water shortage environments during two seasons. Highly significant variations were shown among accessions in both conditions for examined characteristics. Water shortage conditions reduced the overall wheat yield and strong positive correlation existed among stomatal frequency, leaf venation and grain yield per plant. Population structure analyses based on 90,000 SNP data classified the accessions into four sub-populations which indicated the presence of genetic variability. Marker-trait association (MTA) analyses revealed that 422 significant SNPs at p ≤ 10−3, after crossing the false discovery rate (FDR) <0.05 threshold, were linked with examined attributes. Pleiotropic loci (wsnp_Ex_c8913_14881924 and Tdurum_contig10598_304) were associated with flag leaf area (FLA), stomata size (SS), stomata frequency (SF), leaf venation (LV), number of grain per spike (NGS) and grain yield per plant (GYP), which were located on chromosome 4B and 6B at the positions 173.63cM and 229.64cM, respectively, under water shortage conditions. Pleotropic loci wsnp_Ex_c24167_33416760, wsnp_Ex_c5412_9564046 and Tdurum_contig81797_369 on chromosomes 7A, 2A and 4B at the positions 148.26cM, 261.05cM and 173.63cM, respectively, were significantly linked with stomata and yield indices such as FLA, SS, SF, LV, NGS and GYP under normal and water shortage conditions. The current experiment not only validated several MTAs for studied indices reported in other studies but also discovered novel MTAs significant under water shortage environments. Associated and significant SNPs will be useful in discovering novel genes underpinning water shortage tolerance in bread wheat for producing high-yielding and drought tolerant wheat varieties to fulfill the wheat demand for growing populations.

scholarly journals Genome-Wide Association Mapping through 90K SNP Array for Quality and Yield Attributes in Bread Wheat against Water-Deficit Conditions

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 392
Author(s):  
Hafiz Ghulam Muhu-Din Ahmed ◽  
Muhammad Sajjad ◽  
Yawen Zeng ◽  
Muhammad Iqbal ◽  
Sultan Habibullah Khan ◽  
...  
Keyword(s):  
Grain Yield ◽  
Candidate Genes ◽  
Water Deficit ◽  
Bread Wheat ◽  
Genome Wide Association ◽  
Water Deficit Stress ◽  
Yield Attributes ◽  
Yield And Quality ◽  
Isolation And Characterization ◽  
Genome Wide

The decrease in water resources is a serious threat to food security world-wide. In this regard, a genome-wide association study (GWAS) was conducted to identify grain yield and quality-related genes/loci under normal and water-deficit conditions. Highly significant differences were exhibited among genotypes under both conditions for all studied traits. Water-deficit stress caused a reduction in grains yield and an increase in grains protein contents (GPC) and gluten contents (GLC). Population structure divided the 96 genotypes into four sub-populations. Out of 72 significant marker-trait associations (MTAs), 28 and 44 were observed under normal and water-deficit stress conditions, respectively. Pleiotropic loci (RAC875_s117925_244, BobWhite_c23828_341 and wsnp_CAP8_c334_304253) for yield and quality traits were identified on chromosomes 5A, 6B and 7B, respectively, under normal conditions. Under a water-deficit condition, the pleiotropic loci (Excalibur_c48047_90, Tdurum_contig100702_265 and BobWhite_c19429_95) for grain yield per plant (GYP), GPC and GLC were identified on chromosomes 3A, 4A and 7B, respectively. The pleiotropic loci (BS00063551_51 and RAC875_c28721_290) for GPC and GLC on chromosome 1B and 3A, respectively, were found under both conditions. Besides the validation of previously reported MTAs, some new MTAs were identified for flag leaf area (FLA), thousand grain weight (TGW), GYP, GPC and GLC under normal and water-deficit conditions. Twenty SNPs associated with the traits were mapped in the coding DNA sequence (CDS) of the respective candidate genes. The protein functions of the identified candidate genes were predicted and discussed. Isolation and characterization of the candidate genes, wherein, SNPs were mapped in CDS will result in discovering novel genes underpinning water-deficit tolerance in bread wheat.

scholarly journals Multi-locus genome-wide association mapping for spike-related traits in bread wheat (Triticum aestivum L.)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Parveen Malik ◽  
Jitendra Kumar ◽  
Shiveta Sharma ◽  
Rajiv Sharma ◽  
Shailendra Sharma
Keyword(s):  
Triticum Aestivum ◽  
Bread Wheat ◽  
Genome Wide Association Study ◽  
Triticum Aestivum L ◽  
Genome Wide Association ◽  
Yield Potential ◽  
Genome Wide ◽  
Spike Development ◽  
Global Population ◽  
Combined Data

Abstract Background Bread wheat (Triticum aestivum L.) is one of the most important cereal food crops for the global population. Spike-layer uniformity (the consistency of the spike distribution in the vertical space)-related traits (SLURTs) are quantitative and have been shown to directly affect yield potential by modifying the plant architecture. Therefore, these parameters are important breeding targets for wheat improvement. The present study is the first genome-wide association study (GWAS) targeting SLURTs in wheat. In this study, a set of 225 diverse spring wheat accessions were used for multi-locus GWAS to evaluate SLURTs, including the number of spikes per plant (NSPP), spike length (SL), number of spikelets per spike (NSPS), grain weight per spike (GWPS), lowest tiller height (LTH), spike-layer thickness (SLT), spike-layer number (SLN) and spike-layer uniformity (SLU). Results In total, 136 significant marker trait associations (MTAs) were identified when the analysis was both performed individually and combined for two environments. Twenty-nine MTAs were detected in environment one, 48 MTAs were discovered in environment two and 59 MTAs were detected using combined data from the two environments. Altogether, 15 significant MTAs were found for five traits in one of the two environments, and four significant MTAs were detected for the two traits, LTH and SLU, in both environments i.e. E1, E2 and also in combined data from the two environments. In total, 279 candidate genes (CGs) were identified, including Chaperone DnaJ, ABC transporter-like, AP2/ERF, SWEET sugar transporter, as well as genes that have previously been associated with wheat spike development, seed development and grain yield. Conclusions The MTAs detected through multi-locus GWAS will be useful for improving SLURTs and thus yield in wheat production through marker-assisted and genomic selection.

scholarly journals Genome-Wide Association and Prediction of Male and Female Floral Hybrid Potential Traits in Elite Spring Bread Wheat Genotypes

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 895
Author(s):  
Samira El Hanafi ◽  
Souad Cherkaoui ◽  
Zakaria Kehel ◽  
Ayed Al-Abdallat ◽  
Wuletaw Tadesse
Keyword(s):  
Genomic Selection ◽  
Bread Wheat ◽  
Genome Wide Association ◽  
Hybrid Breeding ◽  
Floral Traits ◽  
Phenotypic Variance ◽  
Spring Bread Wheat ◽  
Genome Wide ◽  
Anther Length ◽  
Anther Extrusion

Hybrid wheat breeding is one of the most promising technologies for further sustainable yield increases. However, the cleistogamous nature of wheat displays a major bottleneck for a successful hybrid breeding program. Thus, an optimized breeding strategy by developing appropriate parental lines with favorable floral trait combinations is the best way to enhance the outcrossing ability. This study, therefore, aimed to dissect the genetic basis of various floral traits using genome-wide association study (GWAS) and to assess the potential of genome-wide prediction (GP) for anther extrusion (AE), visual anther extrusion (VAE), pollen mass (PM), pollen shedding (PSH), pollen viability (PV), anther length (AL), openness of the flower (OPF), duration of floret opening (DFO) and stigma length. To this end, we employed 196 ICARDA spring bread wheat lines evaluated for three years and genotyped with 10,477 polymorphic SNP. In total, 70 significant markers were identified associated to the various assessed traits at FDR ≤ 0.05 contributing a minor to large proportion of the phenotypic variance (8–26.9%), affecting the traits either positively or negatively. GWAS revealed multi-marker-based associations among AE, VAE, PM, OPF and DFO, most likely linked markers, suggesting a potential genomic region controlling the genetic association of these complex traits. Of these markers, Kukri_rep_c103359_233 and wsnp_Ex_rep_c107911_91350930 deserve particular attention. The consistently significant markers with large effect could be useful for marker-assisted selection. Genomic selection revealed medium to high prediction accuracy ranging between 52% and 92% for the assessed traits with the least and maximum value observed for stigma length and visual anther extrusion, respectively. This indicates the feasibility to implement genomic selection to predict the performance of hybrid floral traits with high reliability.

scholarly journals Genome-wide association study identified candidate genes for seed size and seed composition improvement in M. truncatula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhijuan Chen ◽  
Vanessa Lancon-Verdier ◽  
Christine Le Signor ◽  
Yi-Min She ◽  
Yun Kang ◽  
...  
Keyword(s):  
Association Study ◽  
Protein Content ◽  
Seed Size ◽  
Seed Protein ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Strong Positive Correlation ◽  
Seed Composition ◽  
Seed Traits ◽  
Genome Wide

AbstractGrain legumes are highly valuable plant species, as they produce seeds with high protein content. Increasing seed protein production and improving seed nutritional quality represent an agronomical challenge in order to promote plant protein consumption of a growing population. In this study, we used the genetic diversity, naturally present in Medicago truncatula, a model plant for legumes, to identify genes/loci regulating seed traits. Indeed, using sequencing data of 162 accessions from the Medicago HAPMAP collection, we performed genome-wide association study for 32 seed traits related to seed size and seed composition such as seed protein content/concentration, sulfur content/concentration. Using different GWAS and postGWAS methods, we identified 79 quantitative trait nucleotides (QTNs) as regulating seed size, 41 QTNs for seed composition related to nitrogen (i.e. storage protein) and sulfur (i.e. sulfur-containing amino acid) concentrations/contents. Furthermore, a strong positive correlation between seed size and protein content was revealed within the selected Medicago HAPMAP collection. In addition, several QTNs showed highly significant associations in different seed phenotypes for further functional validation studies, including one near an RNA-Binding Domain protein, which represents a valuable candidate as central regulator determining both seed size and composition. Finally, our findings in M. truncatula represent valuable resources to be exploitable in many legume crop species such as pea, common bean, and soybean due to its high synteny, which enable rapid transfer of these results into breeding programs and eventually help the improvement of legume grain production.

scholarly journals A Genome-Wide Association Study To Understand the Effect of Fusarium verticillioides Infection on Seedlings of a Maize Diversity Panel

2020 ◽  
Vol 10 (5) ◽  
pp. 1685-1696
Author(s):  
Lorenzo Stagnati ◽  
Vahid Rahjoo ◽  
Luis F. Samayoa ◽  
James B. Holland ◽  
Virginia M. G. Borrelli ◽  
...  
Keyword(s):  
Association Study ◽  
Genome Wide Association Study ◽  
Germination Rate ◽  
Fusarium Verticillioides ◽  
Screening Method ◽  
Significant Snps ◽  
Genome Wide Association ◽  
Genome Wide ◽  
Seedling Length ◽  
A Genome

Fusarium verticillioides, which causes ear, kernel and stem rots, has been reported as the most prevalent species on maize worldwide. Kernel infection by F. verticillioides results in reduced seed yield and quality as well as fumonisin contamination, and may affect seedling traits like germination rate, entire plant seedling length and weight. Maize resistance to Fusarium is a quantitative and complex trait controlled by numerous genes with small effects. In the present work, a Genome Wide Association Study (GWAS) of traits related to Fusarium seedling rot was carried out in 230 lines of a maize association population using 226,446 SNP markers. Phenotypes were scored on artificially infected kernels applying the rolled towel assay screening method and three traits related to disease response were measured in inoculated and not-inoculated seedlings: plant seedling length (PL), plant seedling weight (PW) and germination rate (GERM). Overall, GWAS resulted in 42 SNPs significantly associated with the examined traits. Two and eleven SNPs were associated with PL in inoculated and not-inoculated samples, respectively. Additionally, six and one SNPs were associated with PW and GERM traits in not-inoculated kernels, and further nine and thirteen SNPs were associated to the same traits in inoculated kernels. Five genes containing the significant SNPs or physically closed to them were proposed for Fusarium resistance, and 18 out of 25 genes containing or adjacent to significant SNPs identified by GWAS in the current research co-localized within QTL regions previously reported for resistance to Fusarium seed rot, Fusarium ear rot and fumonisin accumulation. Furthermore, linkage disequilibrium analysis revealed an additional gene not directly observed by GWAS analysis. These findings could aid to better understand the complex interaction between maize and F. verticillioides.

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