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.

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.

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.

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.

Rhodotypos scandens (Thunb.) Makino is known to have a seed dispersal that is thick and stony (endocarp + seeds) and has potential as a landscaping tree seed. In several Rosaceae species, seeds are covered with a hard endocarp, making the internal seeds water-impermeable and germination difficult. Here, we analyzed the morphoanatomical traits and germination properties of R. scandens seeds. To identify ideal seed propagation conditions, we immersed R. scandens seeds in sulfuric acid for varying durations and subjected them to phytohormone (gibberellic acid A3 and fluridone) and a cold stratification (CS) (5 °C) treatment after endocarp removal (ER). The R. scandens stony seeds did not increase in mass by ≥25.0%. Following ER, the seed mass increased by ≥50.0% with water absorption when compared to the initial dry mass. Seed surfaces showed damage and cracks through scarification after 1 h of immersion in sulfuric acid, failing to germinate. A combination of ER, phytohormone treatment, and CS improved seed germination compared to ER alone (26.0 ± 5.3%). Overall, R. scandens seeds showed a dispersal with a hard endocarp from the parent plant, and a pre-treatment with ER, phytohormones, and CS was required for effective seed propagation.

This study predicted habitat distribution changes according to the current distribu seedtion 14 and future climate using the MaxEnt model for endangered Abies nephrolepis Maxim., which is vulnerable to 15 climate change and is a least-concerned species. This study aimed to predict the current distribution and future habitat distribution changes of the endangered A. nephrolepis under climate change using the MaxEnt model. The purpose was to predict the future habitat of the declining A. nephrolepis, to identify the necessity of in situ conservation, and to devise appropriate ex situ seed storage methods. The study utilized climate data from 513 GPS coordinates of A. nephrolepis habitats in South Korea to predict the changes in habitat distribution using the MaxEnt model. The seeds used in the seed experiment were collected from Pyeongchang-gun, Gangwon-do, Republic of Korea in 2019. After confirming an initial seed filling, germination tests were performed under constant temperatures of 15, 20, and 25 °C and alternating day/night temperatures of 25/5, 25/10, 25/10, 20/15, 25/15, 30/15, and 35/15 °C. The seed germination conditions were investigated under 10 different temperature settings. For the determination of storage behavior, seeds were dried at a consistent temperature of 15 °C and relative humidity (eRH) levels of 15, 20, 30, 40, and 50%. Subsequently, the seeds were stored for three months at temperatures of −20 °C and 5 °C, and the vitality tests of the seeds were conducted. Based on these experiments, the storage characteristics of seeds were identified. The results indicated that in all SSP scenarios, it is predicted that A. nephrolepis will become extinct in its habitat by the 2090s. Therefore, it has been shown that on-site and ex situ conservation is necessary. As a result of the seed germination characteristics, the highest germination rate (52.5 ± 16.01%) was achieved at a constant temperature of 20 °C, followed by 25 °C (50.0 ± 10.81%) and 25/10 °C (47.5 ± 4.79%). The highest viability was obtained under 20% eRH (64.0 ± 0%) but was not statistically different from that determined immediately after seed collection. The moisture content was approximately 4.33% fresh weight under 15% eRH at 15 °C. A. nephrolepis seeds are classified as orthodox-type seeds, which do not lose viability at 3%–7% moisture content and after drying under 15% eRH conditions at 15 °C. In conclusion, it can be observed that the seeds can be stored long-term at −20 °C. This research was conducted as a basic study to predict the habitat distribution of the endangered species A. nephrolepis and to establish seed conservation methods. According to the results, it is deemed necessary to conduct both domestic and international analyses of the habitat of A. nephrolepis. In addition, the germination and storage characteristics of A. nephrolepis seeds were confirmed, and based on this, effective seed conservation methods were suggested.