Selecting recombinants to stack high protein with high oleic acid and low linolenic acid in soybean (glycine max)

Authors: MCDONALD, SAMUEL - University Of Georgia; Bilyeu, Kristin; KOEBERNICK, JENNY - Auburn University; BUCKLEY, BLAIR - Louisiana State University; Fallen, Benjamin; Mian, Rouf; LI, ZENGLU - University Of Georgia

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2023
Publication Date: 8/2/2023
Citation: Mcdonald, S.C., Bilyeu, K.D., Koebernick, J., Buckley, B., Fallen, B.D., Mian, R.M., Li, Z. 2023. Selecting recombinants to stack high protein with high oleic acid and low linolenic acid in soybean (glycine max). Plant Breeding. 142(4):477-488. https://doi.org/10.1111/pbr.13102.
DOI: https://doi.org/10.1111/pbr.13102

Interpretive Summary: Soybean breeding for variety development with multiple seed composition targets is hampered by the need for increased numbers of selected alleles. The objective of this work was to devise and implement a marker assisted selection strategy for three populations that enabled capture of an important oil quality trait along with a protein content trait controlled by a total of five genes, and required identification of recombination between two of those selected genes. Once soybean lines were identified, they were analyzed in field experiments for seed composition characteristics and agronomic performance compared to the parent lines. The results indicated that the seed composition traits could be successfully combined without interference, and that the new combination of traits could be selected with elite yield performance. The impact of this research is the development of new soybean germplasm with high yields and unique seed composition characteristics, and the new strategy for soybean breeding for variety development without yield drag.

Technical Abstract: Soybean accounts for over a quarter of the world's oilseed consumption and over 70% of the world's protein meal consumption. The separate development of high oleic, low linolenic acid (HOLL) soybean and high-protein (HP) soybean means that no soybean cultivar on the market has an optimal fatty acid profile and increased protein. The objective of this study was to develop and evaluate high protein, high oleic acid, and low linolenic acid (HP-HOLL) soybean. A five-gene stack was created using a two-phase forward breeding scheme and marker-assisted selection method. Forty-six HP-HOLL lines from three genetic backgrounds were grown in six environments in the Southeast United States. Although genotype-by-environment interaction was significant for seed composition traits, lines met the >75% and <3% cutoffs for oleic acid and linolenic acid, respectively, and met or exceeded the protein concentration of the HP parent. No negative interaction could be detected between the HP and HOLL traits. Additionally, yield testing in four environments indicated yield parity for some lines, suggesting HP and HOLL soybean cultivars with high yield could be selected.