Korean bellflower (Campanula takesimana Nakai) is a rare and perennial herb with medicinal and ornamental values, is endemic to the Ulleung Island of Korea. In this study, we investigated the dormancy-release and germination characteristics of C. takesimana (Campanulaceae) seeds by subjecting them to varying temperatures (5, 10, 15, 20, and 25°C and diurnal/nocturnal temperatures of 15/6, 20/10, and 25/15°C), cold stratification periods (0, 4, 8, or 12 weeks at 5°C), and gibberellic acid (GA₃) concentrations (0, 10, 100, or 1,000 mg·L^-1 at 15/6°C and 25/15°C) to identify the ideal seed propagation conditions. The seeds were stimulated to germinate (at 25°C, 12-h photoperiod with fluorescent lamps at 40 ± 10 μmol∙m^-2∙s^-1) after cold stratification. To examine the germination characteristics, the seeds were tested for water imbibition and found to readily absorb water. The seeds exhibited underdeveloped embryos during dispersal, showed final germination of 37.00% ± 4.43 at 25°C and were not influenced by temperature. The seeds subjected to 0, 4, 8, or 12 weeks of cold stratification germinated at a success rate of 22.00% ± 4.76, 87.00% ± 6.80, 79.00% ± 2.52, and 77.00% ± 1.91, respectively. Additionally, the germination characteristics, which were based on final germination, mean germination time, and germination velocity (Timson index), were significantly greater in the seeds pretreated with 1,000 mg·L^-1 GA₃ at 25/15°C than in seeds pretreated with 0 mg·L^-1 GA₃. Overall, the seeds broke dormancy with GA₃ and short-term cold stratification. Therefore, we concluded that C. takesimana seeds have non-deep, simple, morphophysiological dormancy, and pretreatment with cold stratification and GA₃ is required for effective seed propagation.

This study investigated the kind of seed dormancy and seed germination of Gentiana triflora var. japonica (Kusn.) H. Hara for developing a seed propagation method. The seeds were collected in October 2020 from plants at Mt. Sobaeksan, Korea. In a water imbibition experiment, seed weights increased by >101.9% of their initial masses over 12 h. Effects of incubation temperature (5, 15, 20, 25, 15/6, or 25/15 °C), cold stratification period (5 °C; 0, 4, 8, or 12 weeks), and gibberellic acid (GA₃; 0, 10, 100, or 1000 mg∙L⁻¹) and potassium nitrate treatment (KNO₃; 0, 1000, 2000, or 4000 mg∙L⁻¹) on seed germination were investigated to characterize seed dormancy. These seeds exhibited underdeveloped embryos during seed dispersal. The seeds failed to reach the final germination of 15.0% after treatment at 5, 15, 20, 25, 15/6, or 25/15 °C. After cold stratification for 8 weeks, the germination increased dramatically by >90.0% compared to that at 0 weeks. After the GA₃ treatment, the germination reached >80.0% within 5 days. The final germination was 90.0% in the 100 mg∙L⁻¹ GA₃ treatment group. However, the KNO₃ treatment had no effect on seed germination. Therefore, the G. triflora var. japonica seeds exhibited non-deep simple morphophysiological dormancy.

JunHyeok Kim · Hee Ho Lee · Chung Youl Park · Hyun Min Kim · Young Ho Jung · Sae Hyun Kim · Chae Sun Na. JABC 2022;65:121-8. https://doi.org/10.3839/jabc.2022.017

Vaccinium oldhamii Miq. is an edible berry; however, little is known about its seed dormancy-break and germination. Therefore, the aim of this study was to elucidate the seed-dormancy break and germination characteristics of V. oldhamii. The results showed that the length and width of the seeds of V. oldhamii were 2.4588 ± 0.0273 mm and 1.7028 ± 0.0248 mm, respectively, the filled percentage was 49.0 ± 3.0%, and the 1000-seed weight was 0.9453 g. Additionally, water imbibition test showed that the seed weight of V. oldhamii increased by more than 70% after 24 h, indicating the absence of physical dormancy. Embryo length measured at dispersal and just before germination did not differ significantly. There was no significant difference in E:S (Embryo:Seed) ratio in length at the time of seed dispersal (0.6780 ± 0.0258) and before germination (0.7370 ± 0.0469), indicating the absence of morphological dominance. Temperature treatments showed that the germination of the seed was 0, 6.0, 6.0, 20.0, and 0% under 15, 20, 25, 25/15, and 15/6 °C, respectively. However, treatment with 250 ppm of GA₃ increased the germination of the seeds to 22.0, 36.0, 32.0, 40.0, and 1.0%, respectively. Additionally, treatment with 500 ppm of GA₃ increased the germination to 34.6, 40.0, 40.0, 46.0 %, respectively. These results indicated that the seeds of V. oldhamii exhibited Nondeep physiological dormancy (Nondeep PD). Overall, the findings of this study showed that treatment with 500 ppm of GA₃ at 25/15 °C can effectively break the dormancy of V. oldhamii seeds, which could facilitate further research on the species.

Background: Figwort (Scrophularia buergeriana Miq.) is a biennial plant, whose dried root has been used in traditional medicine. Here, we investigated a viral disease in S. buergeriana, characterized the disease symptoms, and sequenced the complete genome of the identified virus. Methods and Results: Disease symptoms and growth characteristics were compared between two groups of plants, that is, those that were grown from rootlets and those cultivated from seeds. Leaf samples were collected from both groups for RNA sequencing analysis. Primers were designed based on the obtained contig, and the complete genome sequence was determined via reverse transcription polymerase chain reaction and cloning. Viral symptoms were confirmed in figwort plants. The highest incidence of infections was observed at the end of July. The complete genome of Beet western yellows virus (BWYV) ADHS comprised 5,878 nucleotides and seven open reading frames. Phylogenetic analysis based on the nucleotide sequence of the complete genome confirmed that the BWYV ADHS isolate was related most closely to the LS isolate from Korea. Conclusions: This study is the first report of BWYV infection in figwort worldwide. The virus affects plant height and root weight. Control methods should be developed to minimize virus damage in figwort culture.

Boram Kwon ･Hong-Kyu Lee ･Hee-Ji Yang ･So-Yeon Kim･Da-Som Lee ･ChanHoon An ･Tae-Dong Kim･ Chung Youl Park ･Su-Heon Lee. J Plant Biotechnol 2022;49:193-206. https://doi.org/10.5010/JPB.2022.49.3.193