GinMicrosatDb: a genome-wide microsatellite markers database for sesame (Sesamum indicum L.)

Discovering favorable genes, QTLs, and genotypes as a genetic resource for sesame (Sesamum indicum L.) improvement

Sesame (Sesamum indicum L.) is an ancient diploid oilseed crop with high oil content, quality protein, and antioxidant characteristics that is produced in many countries worldwide. The genes, QTLs, and genetic resources of sesame are utilized by sesame researchers and growers. Researchers have identified the many useful traits of this crop, which are available on different platforms. The genes, genotypes, QTLs, and other genetic diversity data of sesame have been collected and stored in more than nine genomic resources, and five sesame crop marker databases are available online. However, data on phenotypic and genotypic variability, which would contribute to sesame improvements, are limited and not yet accessible. The present study comprehensively reviewed more than 110 original published research papers and scientifically incorporated the results. The candidate genes, genotypes, and QTLs of significantly important traits of sesame were identified. Genetic resources related to grain yield and yield component traits, oil content and quality, drought tolerance, salt tolerance, waterlogging resistance, disease resistance, mineral nutrient, capsule shattering resistance, and other agronomic important traits of sesame were studied. Numerous candidate genotypes, genes, QTLs, and alleles associated with those traits were summarized and discovered. The chromosome regions and linkage groups, maps associated with the best traits, and candidate genes were also included. The variability presented in this paper combined with sesame genetic information will help inform further sesame improvement.

Genome-wide association study of vitamin E using genotyping by sequencing in sesame (Sesamum indicum)

BACKGROUND

At least eight structurally related forms of vitamin E occur in nature, four tocopherols and four tocotrienols, all of which are potent membrane-soluble antioxidants. In this study, we detected two major isoforms in sesame (Sesamum indicum L.) seed: γ-tocopherol and β-tocotrienol. The objective of this study is to investigate the genetic basis of these vitamin E isoforms.

METHODS

We  conducted a genome-wide association study (GWAS) using 5962 genome-wide markers, acquired from 96 core sesame accessions. The GWAS was performed using generalized linear (GLM) and mixed linear (MLM) models.

RESULTS

LG08_6621957, on chromosome 8, was detected as having a significant association with γ-tocopherol in both models. It explained 20.9% of γ-tocopherol variation in sesame. For β-tocotrienol, no significant loci were detected according to the two models, but one locus, SLG03_13104062, explained 17.8% of the phenotypic variation. Based on structure and phylogenetic studies, the 96 accessions were clearly clustered into two subpopulations.

CONCLUSION

This study on sesame demonstrates and provides an evidence that genotyping by sequencing (GBS) based GWAS can be used to identifying important loci for small growing crops. The significant SNPs or genes could be useful for improving the vitamin E content in sesame breeding programs.