scholarly journals Genome-wide association analysis uncovers candidate genes for forage quality traits in Brassica napus stems

2020 ◽  
Author(s):  
lijuan wei ◽  
Ruiying Liu ◽  
Wen Xu ◽  
Yan Zhu ◽  
Jinqi Ma ◽  
...  

Abstract Background Brassica napus (rapeseed) is an important oilseed crop and its leaves and stems can also be used as animal feed. Lignocellulose content is closely related to the nutritional quality and palatability of animal feed. However, quantitative trait loci (QTLs) associated with acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents in rapeseed stems have not yet been mapped. Results In this study, we used 494 B. napus accessions to perform genome-wide association studies (GWAS) of ADF and NDF contents. Ninety-two single-nucleotide polymorphisms (SNP) and 35 simple-sequence repeat (SSR) loci were significantly correlated with ADF and NDF contents, respectively, and six genetic loci associated with ADF and NDF contents were detected using both types of markers. We identified three candidate genes on chromosome A05 related to ADF content, including genes encoding chitinase-like protein 2 (CTL2) and two trichome birefringence-like 41 s (TBL41s). Seven genes on chromosomes A03 and A04 were related to NDF content, including genes encoding glycosyl hydrolase (GH), reversibly glycosylated polypeptide 1 (RGP), irregular xylem 12 (IRX12), trichome birefringence-like 34 (TBL34), galacturonosyltransferase 7 (GAUT7), cytokinesis defective 1 (CYT1), and LOB domain-containing protein 15 (LBD15). These candidate genes encode factors that likely participate in secondary cell wall formation and lignocellulose biosynthesis. Conclusions These findings lay the foundation for identifying genes related to forage quality traits and improving the efficiency of forage utilization in rapeseed, which will be beneficial for breeding new varieties for high-quality forage with low lignocellulose content.

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhongchun Xiao ◽  
Chao Zhang ◽  
Fang Tang ◽  
Bo Yang ◽  
Liyuan Zhang ◽  
...  

Abstract Background Increasing seed oil content is one of the most important targets for rapeseed (Brassica napus) breeding. However, genetic mechanisms of mature seed oil content in Brassica napus (B. napus) remain little known. To identify oil content-related genes, a genome-wide association study (GWAS) was performed using 588 accessions. Results High-throughput genome resequencing resulted in 385,692 high-quality single nucleotide polymorphism (SNPs) with a minor allele frequency (MAF) > 0.05. We identified 17 loci that were significantly associated with seed oil content, among which 12 SNPs were distributed on the A3 (11 loci) and A1 (one loci) chromosomes, and five novel significant SNPs on the C5 (one loci) and C7 (four loci) chromosomes, respectively. Subsequently, we characterized differentially expressed genes (DEGs) between the seeds and silique pericarps on main florescences and primary branches of extremely high- and low-oil content accessions (HO and LO). A total of 64 lipid metabolism-related DEGs were identified, 14 of which are involved in triacylglycerols (TAGs) biosynthesis and assembly. Additionally, we analyzed differences in transcription levels of key genes involved in de novo fatty acid biosynthesis in the plastid, TAGs assembly and lipid droplet packaging in the endoplasmic reticulum (ER) between high- and low-oil content B. napus accessions. Conclusions The combination of GWAS and transcriptome analyses revealed seven candidate genes located within the confidence intervals of significant SNPs. Current findings provide valuable information for facilitating marker-based breeding for higher seed oil content in B. napus.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sen Lin ◽  
Cesar Augusto Medina ◽  
O. Steven Norberg ◽  
David Combs ◽  
Guojie Wang ◽  
...  

Autotetraploid alfalfa is a major hay crop planted all over the world due to its adaptation in different environments and high quality for animal feed. However, the genetic basis of alfalfa quality is not fully understood. In this study, a diverse panel of 200 alfalfa accessions were planted in field trials using augmented experimental design at three locations in 2018 and 2019. Thirty-four quality traits were evaluated by Near Infrared Reflectance Spectroscopy (NIRS). The plants were genotyped using a genotyping by sequencing (GBS) approach and over 46,000 single nucleotide polymorphisms (SNPs) were obtained after variant calling and filtering. Genome-wide association studies (GWAS) identified 28 SNP markers associated with 16 quality traits. Among them, most of the markers were associated with fiber digestibility and protein content. Phenotypic variations were analyzed from three locations and different sets of markers were identified by GWAS when using phenotypic data from different locations, indicating that alfalfa quality traits were also affected by environmental factors. Among different sets of markers identified by location, two markers were associated with nine traits of fiber digestibility. One marker associated with lignin content was identified consistently in multiple environments. Putative candidate genes underlying fiber-related loci were identified and they are involved in the lignin and cell wall biosynthesis. The DNA markers and associated genes identified in this study will be useful for the genetic improvement of forage quality in alfalfa after the validation of the markers.


2018 ◽  
Vol 19 (9) ◽  
pp. 2794 ◽  
Author(s):  
Rong Zhou ◽  
Komivi Dossa ◽  
Donghua Li ◽  
Jingyin Yu ◽  
Jun You ◽  
...  

Sesame is poised to become a major oilseed crop owing to its high oil quality and adaptation to various ecological areas. However, the seed yield of sesame is very low and the underlying genetic basis is still elusive. Here, we performed genome-wide association studies of 39 seed yield-related traits categorized into five major trait groups, in three different environments, using 705 diverse lines. Extensive variation was observed for the traits with capsule size, capsule number and seed size-related traits, found to be highly correlated with seed yield indexes. In total, 646 loci were significantly associated with the 39 traits (p < 10−7) and resolved to 547 quantitative trait loci QTLs. We identified six multi-environment QTLs and 76 pleiotropic QTLs associated with two to five different traits. By analyzing the candidate genes for the assayed traits, we retrieved 48 potential genes containing significant functional loci. Several homologs of these candidate genes in Arabidopsis are described to be involved in seed or biomass formation. However, we also identified novel candidate genes, such as SiLPT3 and SiACS8, which may control capsule length and capsule number traits. Altogether, we provided the highly-anticipated basis for research on genetics and functional genomics towards seed yield improvement in sesame.


PLoS ONE ◽  
2017 ◽  
Vol 12 (1) ◽  
pp. e0169234 ◽  
Author(s):  
Elisa Biazzi ◽  
Nelson Nazzicari ◽  
Luciano Pecetti ◽  
E. Charles Brummer ◽  
Alberto Palmonari ◽  
...  

2021 ◽  
Author(s):  
Haijiang Liu ◽  
Jingchi Wang ◽  
Bingbing Zhang ◽  
Xinyu Yang ◽  
John P Hammond ◽  
...  

Abstract Background and Aims Oilseed rape (Brassica napus) is one of the most important oil crops worldwide. Phosphorus (P) deficiency severely decreases the plant height (PH) and branch number (BN) of B. napus. However, the genetic bases controlling PH and BN in B. napus under P deficiency remain largely unknown. This study aims to mine candidate genes for PH and BN by genome-wide association study (GWAS) and determine low-P tolerance haplotypes. Methods An association panel of B. napus were grown in the field with a low P supply (P, 0 kg/ha) and a sufficient P supply (P, 40 kg/ha) across two years and PH and BN were investigated. More than five million single-nucleotide polymorphisms (SNPs) were used to conduct GWAS of PH and BN at two contrasting P supplies. Key Results A total of 2127 SNPs were strongly associated (P &lt; 6.25×10 −07) with PH and BN at two P supplies. There was significant correlation between phenotypic variation and the number of favorable alleles of associated loci on chromosomes A10 (chrA10_821671) and C08 (chrC08_27999846), which will contribute to breeding improvement by aggregating these SNPs. BnaA10g09290D and BnaC08g26640D were identified to be associated with the chrA10_821671 and chrC08_27999846, respectively. Candidate gene association analysis and haplotype analysis showed that the inbred lines carrying ATT at 'BnaA10g09290Hap1' and AAT at 'BnaC08g26640Hap1' had higher PH than lines carrying other haplotype alleles at low P supply. Conclusion Our results demonstrate the power of GWAS in identifying genes of interest in B. napus and provided insights into the genetic basis of PH and BN at low P supply in B. napus. Candidate genes and favorable haplotypes may facilitate marker-based breeding efforts aimed at improving P use efficiency in B. napus.


2016 ◽  
Vol 7 ◽  
Author(s):  
Niklas Körber ◽  
Anja Bus ◽  
Jinquan Li ◽  
Isobel A. P. Parkin ◽  
Benjamin Wittkop ◽  
...  

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