Seed Dormancy Class and Germination Characteristics of Berberis amurensis var. latifolia Nakai, Native to Korea

Abstract

Berberis amurensis var. latifolia Nakai is a plant native to the Ulleung Island in Korea. In this study, we aimed to identify seed dormancy-breaking and germination requirements of this species using water imbibition experiments, gibberellic acid (GA3) treatment (0, 10, 100, or 1000 mg/L), cold stratification (0, 2, 4, 8, or 12 weeks at 5 °C), move-along experiments, and phenological studies. In the water imbibition experiment, the seed weight increased by more than 120% after 24 h. Analysis of the internal morphological characteristics of the seeds revealed that the embryo in freshly matured seeds was fully grown and did not grow thereafter. The final germination percentages after 12 weeks of cold stratification at 5 °C were 49 ± 6.4% and 63 ± 3.4% under light and dark conditions, respectively. In move-along and phenological studies, a longer cold stratification treatment period resulted in a higher germination percentage; however, the warm stratification treatment did not affect germination significantly. The GA3 treatment had little effect on seed germination. Therefore, we concluded that B. amurensis var. latifolia seeds have intermediate physiological dormancy, and pre-treatment with cold stratification for 12 weeks and incubation in the dark are required for effective seed propagation.