Genome-wide association for mapping QTLs linked to protein and oil contents in soybean

Douglas Antônio Dias,Glacy Jaqueline Da Silva,Leandra Regina Texeira Polo,Ivan Schuster,Fabiane Lazzari

doi:10.1590/s0100-204x2017001000009

Abstract

Abstract: The objective of this work was to identify single-nucleotide polymorphism (SNP) markers linked with quantitative trait loci (QTLs) associated with increased contents of protein and oil in soybean. A total of 169 Brazilian soybean varieties, genotyped with 6,000 SNP markers, were evaluated. Protein and oil contents were obtained with the near-infrared reflectance method. Correlation and multiple linear regression analyses were used to identify linkage disequilibrium between SNP markers and the QTLs associated with the two characteristics. Seven QTLs were found to be associated with protein content, on six chromosomes (2, 6, 11, 12, 13, and 16), explaining 60.9% of the variation in this trait. For oil content, eight QTLs were identified on six chromosomes (1, 4, 5, 6, 17, and 19), explaining 78.3% of the variation in the trait. The correlation between the number of loci containing favorable alleles and the evaluated characteristics was 0.49 for protein content and 0.60 for oil content. The molecular markers identified are mapped in genomic regions containing QTLs previously mapped for both characteristics, which reinforces the association between these regions and the genetic control of oil and protein contents in soybean.

Highlights

Soybean (Glycine max L.) is the world’s main source of plant protein and oil, providing approximately 20 to 24% of the oil and fat consumed worldwide (Cavalcante et al, 2009)
After filtering the markers for minor allele frequency (MAF) higher than 5% and lost data lower than 10%, 4,962 single-nucleotide polymorphism (SNP) were used to analyze genome association
A significant association was observed for markers in all of the 20 chromosomes, for protein content, and in all chromosomes, except 7 and 16, for oil content (Figure 2)

Summary

Introduction

Soybean (Glycine max L.) is the world’s main source of plant protein and oil, providing approximately 20 to 24% of the oil and fat consumed worldwide (Cavalcante et al, 2009). This legume has the greatest concentration of protein of all food crops. QTL mapping using linkage disequilibrium infers the association between genotypes (or haplotypes) and phenotypes by evaluating the genetic polymorphism generated in different genetic backgrounds, throughout many recombination generations (Dekkers & Hospital, 2002; Nordborg & Tavaré, 2002)

Objectives

Methods

Results

Conclusion