Do-Hyun Kim

Berberis amurensis var. quelpaertensis (Nakai) Nakai is an endemic shrub species in Korea with considerable conservation importance; however, information regarding its propagation remains limited. This study aimed to characterize its seed dormancy type and identify optimal germination requirements. Water imbibition tests demonstrated that seed weight increased by >21% in 24 h, indicating a permeable seed coat and the lack of physical dormancy (PY). Additionally, morphological analysis revealed that embryos were completely developed at the time of seed dispersal, indicating the non-occurrence of morphophysiological dormancy (MPD). The results from modified move-along and stratification experiments showed that germination was notably enhanced by cold stratification at 5 °C; however, it also occurred following a prolonged period (>68 weeks) of warm stratification alone. Therefore, we conclude that the seeds of B. amurensis var. quelpaertensis exhibit intermediate physiological dormancy, which may represent a “bet-hedging” strategy adapted to the unique conditions of their alpine environment.

Crop wild relatives (CWRs) are critical resources for crop improvement and addressing food security. The genus Solanum includes many wild species genetically related to major crops. However, seed propagation methods for Solanum taxa distributed on the Korean Peninsula are not well-established. In this study, seed morphology and effects of incubation conditions on germination and dormancy were evaluated in 6 Solanum species classified as CWRs in Korea: Solanum lyratum, S. japonense, S. nigrum, S. sarrachoides, S. americanum, and S. viarum. The seeds possessed fully developed embryos at the time of dispersal and the seed coats readily absorbed water. We investigated germination characteristics under various temperatures, cold stratification periods, and gibberellic acid (GA₃) concentrations. Germination percentage of S. lyratum and S. japonense was significantly higher under cold stratification (≥62.0% after 12 weeks at 5 °C) or GA₃ treatment (≥77.0% at 1000 mg·L⁻¹) than for temperature treatment alone (≤3.0% at 25/15 °C), indicating non-deep physiological dormancy (PD). Seeds of S. nigrum, S. americanum, and S. viarum exhibited non-deep PD with conditional dormancy and higher germination efficiencies through GA₃ 1000 mg·L⁻¹ than under temperature treatment alone (25/15 °C). Seeds of S. sarrachoides were classified as non-dormant. These findings may contribute to the practical mass propagation of Solanum.

Vaccinium oldhamii, a blueberry species native to Korea, is a deciduous shrub in the Ericaceae family. Its fruit possesses various pharmacological properties, including anti-inflammatory effects and potential for treating osteoporosis. This study evaluated the effects of five fertilization concentration levels using Multifeed 20 (N:P:K = 20:20:20) on the growth and physiological characteristics of one-year-old V. oldhamii container seedlings. Treatments included 0 g·L⁻¹ (control), 0.5, 1.0, 1.5, and 2.0 g·L⁻¹. Increases in stem thickness, root length, and total dry weight were observed in the control, 0.5, 1.0, and 1.5 g·L⁻¹ treatments, whereas growth declined at 2.0 g·L⁻¹. Mortality rates exceeded 15% at concentrations above 1.0 g·L⁻¹. Photosynthetic capacity and chlorophyll content increased with fertilization. However, while growth improved with increasing fertilizer up to a certain level, it declined at the highest concentration. A fertilization rate of 0.5 g·L⁻¹ proved to be the most economically and environmentally efficient for producing healthy seedlings. This study provides the first fertilization threshold for V. oldhamii, offering practical guidance for nursery production and forming a foundation for future domestication strategies.

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.

Berberis koreana Palibin is an endemic plant native to Korea. In this study, we aimed to study the seed germination of this species using a water imbibition experiment, gibberellic acid (GA₃) treatment (0, 10, 100, or 1000 mg·L⁻¹), cold stratification (0, 2, 4, 8, or 12 weeks at 4 °C), move-along experiment, and phenology studies. In the water imbibition experiment, the weight of the seeds increased by more than 120% in 24 h. An analysis of the internal and external morphological characteristics of the seed revealed that the embryo was already fully grown from the fruit and did not grow thereafter. The final germination percentages for the cold stratification at 0, 2, 4, 8, and 12 weeks at 4 °C were 12 ± 3.65, 32 ± 9.09, 59 ± 1.00, 59 ± 9.59, and 71 ± 1.91%, respectively. In the move-along experiment and phenology studies, a longer low-temperature treatment period resulted in a higher germination percentage. However, the GA₃ treatment had little effect on the seed germination. Our results indicate that B. koreana exhibits an intermediate physiological seed dormancy.

Berberis koreana Palibin is an endemic plant native to Korea. In this study, we aimed to study seed germination in this species using a water imbibition experiment, gibberellic acid (GA3) treat-ment (0, 10, 100, or 1000 mg·L−1), cold stratification (0, 2, 4, 8, or 12 weeks at 4 °C), a move-along experiment, and phenology studies. In the water imbibition experiment, the weight of the seeds increased by more than 120% in 24 h. Analysis of the internal and external morphological char-acteristics of the seed revealed that the embryo was already fully grown from the fruit and did not grow thereafter. The final germination percentages for cold stratification at 0, 2, 4, 8, and 12 weeks at 4 °C were 12, 32, 59, 59, and 71%, respectively. In the move-along experiment and phe-nology studies, a longer low-temperature treatment period resulted in a higher germination percentage. However, the GA3 treatment had little effect on seed germination. Our results indi-cate that B. koreana exhibits intermediate physiological seed dormancy.