Our work has led to the development and release of several high EPV cultivars/germplasm. The conventional high-yielding, high EPV variety ‘R18-14502’ was released in 2023. This indeterminate soybean has a relative maturity of 4.9 and its seeds have on average 36.6% protein and 18.3% oil at 13% moisture. Manuscript preparation for the release and registration of high-oil MG-V line N17-2520 is now complete to be submitted to the Journal of Plant Registration soon. This line has 21% oil on 13% moisture with competitive yield with checks and 47.5% meal protein. In 2024, two conventional high oil lines are released, S19-10701 and S19-12537. S19-10701 (relative maturity 4.5) is a high-yielding, high oil cultivar with good seed quality. It yielded 105.2% of the non-Xtend check mean and 92.7% of the Xtend check mean, with 19.4% seed oil and 34.9% seed protein. S19-12537 (relative maturity 5.0) yielded 107.5% of the non-Xtend check mean and 98.3% of the Xtend check mean, with 19.9% seed oil and 34.9% seed protein. Numerous breeding lines ranging from MG 0 to V are in stages 1-3 of field testing and will be released in the coming years.
This project has made progress in translating genetic findings related to maximizing seed oil and protein content to farmers fields in the form of new cultivars/germplasm. With previous USB support, we were able to identify loci from a genome-wide association study that had a negligible negative relationship between protein and oil concentrations in the seed. In this work, the beneficial alleles from plant introductions were introgressed via marker assisted selection into adapted genetic backgrounds and are being field tested. We were able to report on seven QTL and their impact on estimated processing value. This work has been submitted for publication and the impact of these alleles on yield will be assessed in future work. Additionally, a manuscript aiming to identify significant marker-trait associations for seed protein, oil, and amino acids, as well as to evaluate the environmental stability of seed protein in a panel of 449 genetically diverse PIs was submitted for publication at Scientific Reports.
Our teamwork demonstrated that the introduction of transgenes in soybean has been successful to produce novel compounds that best fit for aquaculture diet requirements, such as novel omega-3 fatty acids and antioxidants. However, the transgenic lines exhibited significant alterations in their overall metabolic profile, particularly with an increased level of free amino acids, and reductions in embryo size, total oil, starch, and chlorophyll content. C13-labeling highlighted key metabolic pathways active during soybean embryo development, which will be crucial to understand how we can overcome the metabolic limitations caused by the introduction of the transgenes.