Genome analysis to identify SNPs associated with oil content and fatty acid components in soybean

Abstract

The nutritional value, flavor and stability of soybean oil are determined by its five dominant fatty acids: saturated palmitic and stearic, monounsaturated oleic, and polyunsaturated linoleic and linolenic acids. Identifying molecular markers or quantitative trait loci associated with these components has the potential to facilitate the development of improved varieties and thus improve soybean oil content and quality. In this study, we used the BARCSoySNP6K BeadChip array to conduct a genome analysis of diverse soybean accessions evaluated for 2 years under Brazilian field conditions. The results demonstrated high broad-sense heritability, suggesting that the soybean genotype panel could be useful for oil trait breeding programs. Moreover, the range of oil trait variation among the plant introductions (PIs) was superior to that among the Brazilian cultivars in this study, indicating that a PI population could be used to find genes controlling these traits. The genome analysis showed that the genetic structure of the soybean germplasm comprised two main genetic groups, and it revealed linkage disequilibrium decay of approximately 300 kb. A total of 19 single-nucleotide polymorphism (SNP) loci on ten different chromosomes significantly associated with palmitic acid, oleic acid and total oil contents were discovered. Analysis of the SNP annotations revealed enzymes associated with several oil-related physiological metabolisms. Loci and specific alleles in our soybean panel that contributed to lower palmitic acid contents and higher oleic acid and total oil contents were identified. Overall, this genome analysis confirmed previous findings and identified SNP markers that may be useful to rapidly improve oil traits in soybean.