Identification of environmentally stable wild soybean genotypes with high alpha-linolenic acid concentration

Increasing alpha-linolenic acid (ALA) in soybean [Glycine max (L.) Merr] seed oil is an important breeding goal in soybean because of its beneficial effects on human health. Seed oil of wild soybeans (G. soja Sieb. & Zucc.) generally has about twice the ALA concentration than seed oil from cultivated soybeans. Therefore, identification of wild soybean genotypes with high and stable ALA concentration over various growing conditions would be useful for breeding purposes. The objective of this study was to evaluate wild soybeans with high ALA for environmental stability. Fifteen wild soybean accessions with relatively high ALA concentrations (~170 to 200 g kg⁻¹) and three check cultivars were evaluated across seven growing environments to determine the stability of ALA concentration. The ALA concentration of the wild soybean genotypes ranged from 169 to 191 g kg⁻¹ with an average of 181 g kg⁻¹. Seed of wild soybean genotypes had more than twice the amount of ALA than seed of the two cultivated soybeans, Williams 82 (72 g kg⁻¹) and Daewonkong (78 g kg⁻¹). CW13755 (185 g kg⁻¹) and CW13943 (191 g kg⁻¹) were the most stable across seven environments among all wild soybean accessions tested followed by CW13944 (191 g kg⁻¹) and CW01022 (169 g kg⁻¹) compared with the three checks. In conclusion, these environmentally stable wild soybean accessions with elevated ALA should be excellent germplasm sources to improve the ALA concentration in soy oil and to study the mechanism of ALA accumulation in soybean.