Sulfuric acid effects in seed dormancy break of <i>Ipomoea batatas</i> evaluated by enzymatic, anatomic and physiological approaches

ABSTRACT The recommended method to overcome seed coat dormancy in sweet potato seeds is exposure to sulfuric acid, which can damage the embryo and affect seedling development depending on exposure time. This study aimed to determine the ideal immersion period using physiological, anatomical, and enzymatic analyses. Seeds were scarified with concentrated sulfuric acid for nine immersion periods. Physiological analyses included germination tests, germination speed index, first germination count, emergence test, and emergence speed index. Image analysis quantified the primary root length, root‐to‐hypocotyl ratio, and seedling length. Catalase and superoxide dismutase enzyme activities were analysed. Seed coat anatomy, including thickness, wear, and colour, was also assessed. Exposure to sulfuric acid for 30 min effectively broke dormancy without impacting the antioxidant system or seedling development. Thermal chambers confirmed that chemically scarified seeds absorb water and activate metabolism faster. Plant anatomy helped illustrate how sulfuric acid breaks dormancy by eroding physical barriers.