Acid Scarification Completes the Germination of Hovenia dulcis Seeds

Seeds have been reported to have a combination of physical and physiological dormancy. However, this study revealed that H. dulcis seeds only have physical dormancy. The water absorption of the seeds after different periods of sulfuric acid scarification was measured, and the water gap through which water was absorbed after scarification treatment was specified. Cold stratification treatment and gibberellic acid treatment were performed after sulfuric acid scarification to determine whether H. dulcis seeds had physiological dormancy. H. dulcis seeds could absorb water completely when scarified for more than 60 min, and water was absorbed only through the hilar fissure near the micropyle, indicating that H. dulcis seeds have physical dormancy. However, there was no synergistic effect on the final seed germination percentage after the cold stratification or gibberellic acid treatments, and germination was delayed under cold temperature conditions. Thus, it was concluded that H. dulcis seeds have no physiological dormancy but only physical dormancy. This study not only clarifies the kind of dormancy in H. dulcis seeds but also provides a method to expedite seed germination without a long cold stratification treatment period of 2 or 3 months.

Automated summary

This study revealed that H. dulcis seeds have only physical dormancy, but no physiological dormancy. Water absorption and scarification treatments were used to determine the dormancy type, and additional treatments were performed to confirm the absence of physiological dormancy. The results showed that H. dulcis seeds only have physical dormancy and cannot be promoted to germination by cold stratification or gibberellic acid treatments.