Evaluation and Heritability Analysis of the Seed Vigor of Soybean Strains Tested in the Huanghuaihai Regional Test of China

High seed vigor is a prerequisite for high and stable yield. At present, seed vigor is not considered a goal of soybean breeding in China. Therefore, the seed vigor status of soybean strains is unclear. In this study, the seed vigor of 131 soybean strains included in the Huanghuaihai regional test in 2019 was measured using the artificial accelerated aging method. Significant (p < 0.01) differences in seed vigor were found, with a coefficient of variation of four vigor indexes being more than 48%. The strains with high vigor only accounted for 28.24%, indicating the seed quality of the tested strains was generally not high. Furthermore, the seed vigor of four representative strains selected from each of three vigor types was evaluated using multiyear and multilocation experiments. The seed vigor indexes of high-vigor-type strains were the most stable, while medium- and low-vigor-type strains varied under different environmental conditions. The generalized heritability of the four vigor indexes of the three vigor types was more than 51% and in the order of high vigor type > low vigor type > medium vigor type. Our results suggested that the genotypes of high-vigor-type strains have a greater influence on seed vigor, so to ensure varieties with high seed vigor, this criterion should be prioritized in soybean breeding programs in China.