Identification of quantitative trait loci (<scp>QTL</scp>s) for seed protein concentration in soybean and analysis for additive effects and epistatic effects of <scp>QTL</scp>s under multiple environments

Abstract

Abstract Soybean protein concentration is a key trait driver of successful soybean quality. A recombination inbred lines derived from a cross between ‘ C harleston’ and ‘ D ongnong594’, were planted in three environments across four years in C hina. Then, the genetic effects were partitioned into additive main effects, epistatic main effects and their environment interaction effects by using composite interval mapping, multiple interval mapping and composite interval mapping in a mixed linear model. Forty‐three quantitative trait loci QTL s were identified on 17 of 20 soybean chromosomes excluding Ch 7, Ch 8 and Ch 17. Two QTL s showed a good stability across multiple environments, q PRO 20‐1 was detected under four environments, which explained 4.4–9.95% phenotypic variances and the allele was from ‘ C harleston’ among four environments. q PRO 7‐5 was detected under three environments, which explained 7.2–14.5% phenotypic variances and the allele was from ‘ D ongnong 594’, three pathway genes of protein biosynthesis were detected in the interval of q PRO 7‐5. The additive main‐effect QTL s contributed more phenotypic variation than the epistasis and environmental interaction. This indicated that it is feasible by marker‐assisted selection to improve soybean protein concentration.