scholarly journals Identification of Novel Loci and Candidate Genes for Resistance to Powdery Mildew in a Resequenced Cucumber Germplasm

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 584
Author(s):  
Xiaoping Liu ◽  
Xingfang Gu ◽  
Hongwei Lu ◽  
Panna Liu ◽  
Han Miao ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Candidate Genes ◽  
Yield Loss ◽  
Genome Wide Association Study ◽  
Natural Infection ◽  
Disease Index ◽  
Potential Contribution ◽  
Homologous Genes ◽  
Genome Wide ◽  
S Genes

Powdery mildew (PM) is one of the most serious diseases in cucumber and causes huge yield loss. Multiple quantitative trait loci (QTLs) for PM resistance have been reported in previous studies using a limited number of cucumber accessions. In this study, a cucumber core germplasm (CG) consisting of 94 resequenced lines was evaluated for PM resistance in four trials across three years (2013, 2014, and 2016). These trials were performed on adult plants in the field with natural infection. Using genome-wide association study (GWAS), 13 loci (pmG1.1, pmG1.2, pmG2.1, pmG2.2, pmG3.1, pmG4.1, pmG4.2, pmG5.1, pmG5.2, pmG5.3, pmG5.4, pmG6.1, and pmG6.2) associated with PM resistance were detected on all chromosomes except for Chr.7. Among these loci, ten were mapped to chromosomal intervals where QTLs had been reported in previous studies, while, three (pmG2.1, pmG3.1, and pmG4.1) were novel. The loci of pmG2.1, pmG5.2, pmG5.3 showed stronger signal in four trials. Based on the annotation of homologous genes in Arabidopsis and pairwise LD correlation analysis, candidate genes located in the QTL intervals were predicted. SNPs in these candidate genes were analyzed between haplotypes of highly resistant (HR) and susceptible (HS) CG lines, which were defined based on combing disease index data of all trials. Furthermore, candidate genes (Csa5G622830 and CsGy5G015660) reported in previous studies for PM resistance and cucumber orthologues of several PM susceptibility (S) genes (PMR5, PMR-6, and MLO) that are colocalized with certain QTLs, were analyzed for their potential contribution to the QTL effect on both PM and DM in the CG population. This study shows that the CG germplasm is a very valuable resource carrying known and novel QTLs for both PM and DM resistance, which can be exploited in cucumber breeding.

Genome-wide association study of physical and microstructure-related traits in peanut shell

2021 ◽  
pp. 1-11
Author(s):  
Kailu Cui ◽  
Feiyan Qi ◽  
Ziqi Sun ◽  
Jingjing Feng ◽  
Bingyan Huang ◽  
...  
Keyword(s):  
Association Study ◽  
Candidate Genes ◽  
Genetic Basis ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Potential Contribution ◽  
Peanut Shell ◽  
Nucleotide Polymorphisms ◽  
B Genome ◽  
Genome Wide

Abstract Peanut shell plays key roles in protecting the seed from diseases and pest infestation but also in the processing of peanut and is an important byproduct of peanut production. Most studies on peanut shell have focused on the utilization of its chemical applications, but the genetic basis of shell-related traits is largely unknown. A panel of 320 peanut (Arachis hypogaea) accessions including var. hypogaea, var. vulgaris, var. fastigiata and var. hirsuta was used to study the genetic basis of two physical and five microstructure-related traits in peanut shell. Significant phenotypic differences were revealed among the accessions of var. hypogaea, var. hirsuta, var. vulgaris and var. fastigiata for mechanical strength, thickness, three sclerenchymatous layer projections and main cell shape of the sclerenchymatous layer. We identified 10 significant single nucleotide polymorphisms (SNPs) through genome-wide association study (P < 5.0 × 10−6) combining the shell-related traits and high-quality SNPs. In total, 192 genes were located in physical proximity to the significantly associated SNPs, and 11 candidate genes were predicted related to their potential contribution to the development and structure of the peanut shell. All SNPs were detected on the B genome demonstrating the biased contribution of the B genome for the phenotypical make-up of peanut. Exploring the newly identified candidate genes will provide insight into the molecular pathways that regulate peanut shell-related traits and provide valuable information for molecular marker-assisted breeding of an improved peanut shell.

scholarly journals Identification of novel loci and candidate genes for resistance to cucumber powdery mildew using GWAS

2020 ◽  
Author(s):  
Xiaoping Liu ◽  
Hongwei Lu ◽  
Panna Liu ◽  
Han Miao ◽  
Yuling Bai ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Candidate Genes ◽  
Association Analysis ◽  
Genomic Region ◽  
Genome Wide Association ◽  
Pcr Analysis ◽  
The Novel ◽  
Genome Wide Association Analysis ◽  
Homologous Genes ◽  
Genome Wide

Abstract Background Powdery mildew (PM) is one of the most serious diseases in cucumber and causes huge yield loss. Multiple quantitative trait loci (QTLs) for PM resistance have been detected in previous studies, however, none of these studies used the approach of genome-wide association analysis (GWAS). In this study, a cucumber core germplasm (CG) consisting of 109 resequenced lines was evaluated for PM resistance in three seasons. Results twelve loci (pmG1.1, pmG2.1, pmG2.2, pmG3.1, pmG4.1, pmG4.2, pmG5.1, pmG5.2, pmG5.3, pmG5.4, pmG6.1 and pmG6.2) associated with PM resistance were detected on all chromosomes except for Chr.7 using GWAS. Among these loci, pmG2.1, pmG4.1 and pmG6.1 were the novel ones that have not been reported in previous studies. The loci of pmG2.1, pmG5.2, pmG5.3 showed stronger signal in three seasons, for which three candidate genes Csa2G022790, Csa5G484620 and Csa5G604330 were respectively predicted using pairwise LD correlation and qRT-PCR analysis. Further, Csa4G022270 in pmG4.1, Csa6G022350 and Csa6G022370 in pmG6.1 might be the candidate genes based on the annotation of homologous genes in Arabidopsis. Conclusion Twelve Loci related to powdery mildew resistance in cucumber were detected by genome-wide association analysis, three of which namely pmG2.1, pmG4.1 and pmG6.1 are novel. Three candidate genes within the genomic region of locus pmG2.1, pmG5.2 and pmG5.3 were identified, respectively. These results provide targets for gene cloning and genetic breeding of PM resistance in cucumber.

scholarly journals Assessment of the Genetic Diversity of the Breeding Lines and a Genome Wide Association Study of Three Horticultural Traits Using Worldwide Cucumber (Cucumis spp.) Germplasm Collection

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1736
Author(s):  
Hea-Young Lee ◽  
Jeong-Gu Kim ◽  
Byoung-Cheorl Kang ◽  
Kihwan Song
Keyword(s):  
Genetic Diversity ◽  
Powdery Mildew ◽  
Association Study ◽  
Candidate Genes ◽  
Genome Wide Association Study ◽  
Germplasm Collection ◽  
Genome Wide Association ◽  
Breeding Lines ◽  
Horticultural Traits ◽  
Genome Wide

Cucumbers are an important economic vegetable crop that is used for fresh or processing purposes worldwide. In this study, we used 264 accessions that consisted of world-wide wild germplasms and advanced breeding lines in order to understand the genetic diversity and the genetic correlation among the germplasm collection. A genotyping-by-sequencing (GBS) approach was applied to obtain dense genome-wide markers coverage (>12,082 SNPs) to construct a high-density haplotype map. Various population stratification methods were performed, and three subgroups were divided based on the genetic diversity, which reflected their geographic regions. According to the phylogenetic analysis, the breeding lines were separated from wild germplasms, and the two distinct groups were divided within the breeding lines. One of the groups mainly consisted of East-Asian varieties, which showed the unique homogenous genotype patterns. Using this germplasm collection, three important horticultural traits of cucumbers—powdery mildew resistance, spine color, and fruit stalk-end color—were evaluated and used to conduct the genome-wide association study (GWAS). All of the significant SNPs and two novel candidate genes (Csa5G453160 and Csa5G471070) for the powdery mildew were identified in chromosome 5 from the natural population, which is where reported major QTLs from various bi-parental population are located. Furthermore, two candidate genes, Csa1G006300 and Csa3G824850, and four candidate genes, Csa2G368270, Csa3G236570, Csa5G175680, and Csa6G448170, were identified for the spine color and the fruit stalk-end color, respectively. These results are expected to be helpful to develop molecular markers of the horticultural traits in cucumbers.

scholarly journals The Genetic Architecture of Ovariole Number in Drosophila melanogaster: Genes with Major, Quantitative, and Pleiotropic Effects

2017 ◽  
Vol 7 (7) ◽  
pp. 2391-2403 ◽  
Author(s):  
Amanda S Lobell ◽  
Rachel R Kaspari ◽  
Yazmin L Serrano Negron ◽  
Susan T Harbison
Keyword(s):  
Candidate Genes ◽  
Genome Wide Association Study ◽  
Natural Populations ◽  
Direct Role ◽  
Genome Wide ◽  
A Genome ◽  
Fitness Trait ◽  
Sleep Parameters ◽  
Activity Behavior ◽  
Ovariole Number

Abstract Ovariole number has a direct role in the number of eggs produced by an insect, suggesting that it is a key morphological fitness trait. Many studies have documented the variability of ovariole number and its relationship to other fitness and life-history traits in natural populations of Drosophila. However, the genes contributing to this variability are largely unknown. Here, we conducted a genome-wide association study of ovariole number in a natural population of flies. Using mutations and RNAi-mediated knockdown, we confirmed the effects of 24 candidate genes on ovariole number, including a novel gene, anneboleyn (formerly CG32000), that impacts both ovariole morphology and numbers of offspring produced. We also identified pleiotropic genes between ovariole number traits and sleep and activity behavior. While few polymorphisms overlapped between sleep parameters and ovariole number, 39 candidate genes were nevertheless in common. We verified the effects of seven genes on both ovariole number and sleep: bin3, blot, CG42389, kirre, slim, VAChT, and zfh1. Linkage disequilibrium among the polymorphisms in these common genes was low, suggesting that these polymorphisms may evolve independently.

scholarly journals Genome-Wide Association Analysis of Growth Curve Parameters in Chinese Simmental Beef Cattle

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 192
Author(s):  
Xinghai Duan ◽  
Bingxing An ◽  
Lili Du ◽  
Tianpeng Chang ◽  
Mang Liang ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Candidate Genes ◽  
Growth Curve ◽  
Growth And Development ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Coefficient Of Determination ◽  
Nucleotide Polymorphisms ◽  
Genome Wide ◽  
A Genome

The objective of the present study was to perform a genome-wide association study (GWAS) for growth curve parameters using nonlinear models that fit original weight–age records. In this study, data from 808 Chinese Simmental beef cattle that were weighed at 0, 6, 12, and 18 months of age were used to fit the growth curve. The Gompertz model showed the highest coefficient of determination (R2 = 0.954). The parameters’ mature body weight (A), time-scale parameter (b), and maturity rate (K) were treated as phenotypes for single-trait GWAS and multi-trait GWAS. In total, 9, 49, and 7 significant SNPs associated with A, b, and K were identified by single-trait GWAS; 22 significant single nucleotide polymorphisms (SNPs) were identified by multi-trait GWAS. Among them, we observed several candidate genes, including PLIN3, KCNS3, TMCO1, PRKAG3, ANGPTL2, IGF-1, SHISA9, and STK3, which were previously reported to associate with growth and development. Further research for these candidate genes may be useful for exploring the full genetic architecture underlying growth and development traits in livestock.

scholarly journals Genome-Wide Association Study Reveals the Genetic Basis of Cold Tolerance in Rice at the Seedling Stage

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 318
Author(s):  
Tae-Ho Ham ◽  
Yebin Kwon ◽  
Yoonjung Lee ◽  
Jisu Choi ◽  
Joohyun Lee
Keyword(s):  
Association Study ◽  
Candidate Genes ◽  
Cold Tolerance ◽  
Genome Wide Association Study ◽  
Seedling Stage ◽  
Genome Wide Association ◽  
Matrix Analysis ◽  
Rice Seedlings ◽  
Genome Wide ◽  
A Genome

We conducted a genome-wide association study (GWAS) of cold tolerance in a collection of 127 rice accessions, including 57 Korean landraces at the seedling stage. Cold tolerance of rice seedlings was evaluated in a growth chamber under controlled conditions and scored on a 0–9 scale, based on their low-temperature response and subsequent recovery. GWAS, together with principal component analysis (PCA) and kinship matrix analysis, revealed four quantitative trait loci (QTLs) on chromosomes 1, 4, and 5 that explained 16.5% to 18.5% of the variance in cold tolerance. The genomic region underlying the QTL on chromosome four overlapped with a previously reported QTL associated with cold tolerance in rice seedlings. Similarly, one of the QTLs identified on chromosome five overlapped with a previously reported QTL associated with seedling vigor. Subsequent bioinformatic and haplotype analyses revealed three candidate genes affecting cold tolerance within the linkage disequilibrium (LD) block of these QTLs: Os01g0357800, encoding a pentatricopeptide repeat (PPR) domain-containing protein; Os05g0171300, encoding a plastidial ADP-glucose transporter; and Os05g0400200, encoding a retrotransposon protein, Ty1-copia subclass. The detected QTLs and further evaluation of these candidate genes in the future will provide strategies for developing cold-tolerant rice in breeding programs.

scholarly journals Genome-Wide Association Study Identified Novel Candidate Loci/Genes Affecting Lodging Resistance in Rice

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 718
Author(s):  
Bingxin Meng ◽  
Tao Wang ◽  
Yi Luo ◽  
Deze Xu ◽  
Lanzhi Li ◽  
...  
Keyword(s):  
Association Study ◽  
Candidate Genes ◽  
Association Analysis ◽  
Genome Wide Association Study ◽  
Flag Leaf ◽  
Genome Wide Association ◽  
Lodging Resistance ◽  
Leaf Type ◽  
Stem Strength ◽  
Genome Wide

Lodging reduces rice yield, but increasing lodging resistance (LR) usually limits yield potential. Stem strength and leaf type are major traits related to LR and yield, respectively. Hence, understanding the genetic basis of stem strength and leaf type is of help to reduce lodging and increase yield in LR breeding. Here, we carried out an association analysis to identify quantitative trait locus (QTLs) affecting stem strength-related traits (internode length/IL, stem wall thickness/SWT, stem outer diameter/SOD, and stem inner diameter/SID) and leaf type-associated traits (Flag leaf length/FLL, Flag leaf angle/FLA, Flag leaf width/FLW, leaf-rolling/LFR and SPAD/Soil, and plant analyzer development) using a diverse panel of 550 accessions and evaluated over two years. Genome-wide association study (GWAS) using 4,076,837 high-quality single-nucleotide polymorphisms (SNPs) identified 89 QTLs for the nine traits. Next, through “gene-based association analysis, haplotype analysis, and functional annotation”, the scope was narrowed down step by step. Finally, we identified 21 candidate genes in 9 important QTLs that included four reported genes (TUT1, OsCCC1, CFL1, and ACL-D), and seventeen novel candidate genes. Introgression of alleles, which are beneficial for both stem strength and leaf type, or pyramiding stem strength alleles and leaf type alleles, can be employed for LR breeding. All in all, the experimental data and the identified candidate genes in this study provide a useful reference for the genetic improvement of rice LR.

scholarly journals Integration of a single-step genome-wide association study with a multi-tissue transcriptome analysis provides novel insights into the genetic basis of wool and weight traits in sheep

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Bingru Zhao ◽  
Hanpeng Luo ◽  
Xixia Huang ◽  
Chen Wei ◽  
Jiang Di ◽  
...  
Keyword(s):  
Association Study ◽  
Candidate Genes ◽  
Genetic Improvement ◽  
Genome Wide Association Study ◽  
Growth Traits ◽  
Fibre Diameter ◽  
Single Step ◽  
Genome Wide Association ◽  
Six Traits ◽  
Genome Wide

Abstract Background Genetic improvement of wool and growth traits is a major goal in the sheep industry, but their underlying genetic architecture remains elusive. To improve our understanding of these mechanisms, we conducted a weighted single-step genome-wide association study (WssGWAS) and then integrated the results with large-scale transcriptome data for five wool traits and one growth trait in Merino sheep: mean fibre diameter (MFD), coefficient of variation of the fibre diameter (CVFD), crimp number (CN), mean staple length (MSL), greasy fleece weight (GFW), and live weight (LW). Results Our dataset comprised 7135 individuals with phenotype data, among which 1217 had high-density (HD) genotype data (n = 372,534). The genotypes of 707 of these animals were imputed from the Illumina Ovine single nucleotide polymorphism (SNP) 54 BeadChip to the HD Array. The heritability of these traits ranged from 0.05 (CVFD) to 0.36 (MFD), and between-trait genetic correlations ranged from − 0.44 (CN vs. LW) to 0.77 (GFW vs. LW). By integrating the GWAS signals with RNA-seq data from 500 samples (representing 87 tissue types from 16 animals), we detected tissues that were relevant to each of the six traits, e.g. liver, muscle and the gastrointestinal (GI) tract were the most relevant tissues for LW, and leukocytes and macrophages were the most relevant cells for CN. For the six traits, 54 quantitative trait loci (QTL) were identified covering 81 candidate genes on 21 ovine autosomes. Multiple candidate genes showed strong tissue-specific expression, e.g. BNC1 (associated with MFD) and CHRNB1 (LW) were specifically expressed in skin and muscle, respectively. By conducting phenome-wide association studies (PheWAS) in humans, we found that orthologues of several of these candidate genes were significantly (FDR < 0.05) associated with similar traits in humans, e.g. BNC1 was significantly associated with MFD in sheep and with hair colour in humans, and CHRNB1 was significantly associated with LW in sheep and with body mass index in humans. Conclusions Our findings provide novel insights into the biological and genetic mechanisms underlying wool and growth traits, and thus will contribute to the genetic improvement and gene mapping of complex traits in sheep.

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