Fig. 1

The difference between TARS-HT1 and PR9920–171 for physical dormancy. a The germination assay performed on both genotypes with intact and scarified seed coat. This experiment revealed that PR9920–171 possessed strong physical dormancy. b The imbibition assays performed on both beans with intact and scarified seed coat. TARS-HT1 beans imbibed water at a faster pace compared to PR9920–171 beans. Seed coat scarification significantly enhanced imbibition for both genotypes, particularly PR9920–171 beans, indicating strong physical dormancy of this genotype. c Imbibition assay of cotyledons after removal of the seed coats. No significant differences were detected for imbibition rate of the cotyledons, indicating the seed coat is the main contributor of physical dormancy in PR9920–171. d Water uptake rate of PR9920–171 and TARS-HT1 beans grown at three field environments in MI, WA and PR in 2019. In all locations, the PR9920–171 had a significantly lower imbibition rate compared to TARS-HT1. IJR the parental lines of both genotypes showed a slow-imbibition phenotype similar to PR9920–171. The numbers in front of each location indicates the replication number. e Respiration measurement of seeds at different time-points after soaking for PR9920–171 and TARS-HT1 genotypes. The respiration rate in TARS-HT1 seeds followed a faster rate compared to PR9920–171 seeds. The intact seeds of TARS-HT1 reached their maximum respiration capacity at 48 h after soaking. In contrast, the respiration rate in PR9920–171 did not decrease in respiration even after 120 h of soaking. In panel a, b, c, and e, red and blue lines indicate PR9920–171 an TARS-HT1, respectively. Solid and dashed lines indicate the beans with intact and scarified seed coats, respectively