Evaluation of 10 Edamame Breeding Lines to Determine Yield, Agronomic, and Seed Composition Traits

Edamame is a vegetable soybean ( Glycine max ) that is harvested at the R6 growth stage. Although it is relatively new to America, the acreage and market demand of edamame have steadily increased. Developing new cultivars that are more adapted to local environments and crop management systems is significantly important to promoting specialty crop production and meeting the market requirements. In this study, 10 edamame breeding lines and four check cultivars were evaluated during 2020–23 to determine the potential production in the southeastern United States. Among genotypes, there were significant differences in the fresh pod and mature seed yields and agronomic and seed composition traits that were investigated. The year effects and genotype × year interactions were also significant in most cases. Fresh pod and mature seed yields were not significantly correlated with most of other agronomic traits and seed compositions. Over 4 years, the fresh pod yield averaged 11,227.5 kg·ha −1 (range, 9800.1–13,154.3 kg·ha −1 ), and the mature seed yield averaged 2814.7 kg·ha −1 (range, 2029.2–3175.2 kg·ha −1 ). The average 100-seed weight of 14 genotypes was 26.9 g (range, 23.1–30.1 g), and the average seed size of nine breeding lines was larger than that of the check. Maturity occurred on average 153.3 days after planting (range, 147.1–159.5 days). Based on dry weight, seed protein, oil, and sucrose contents had averages of 43.5%, 18.7%, and 5.0%, respectively. The estimates of broad-sense heritability were medium to high (66.82%–94.90%) for most of the traits, whereas the heritability estimates for fresh pod yield and duration from flowering to maturity were relatively low (23.44%–42.29%). Several breeding lines exhibited good yield, larger seed size, and higher contents of protein, oil, and oleic acid, suggesting the potential of release and commercial production.