Gi-Heum Nam

Understanding the dormancy behavior and germination requirements of Crepidiastrum denticulatum (Houtt.) J.H.Pak & Kawano, a valuable vascular plant native to Korea, is essential for establishing an efficient seed propagation protocol. In this study, we developed a propagation method by examining the effects of temperature, light, gibberellic acid (GA₃), and cold stratification to determine whether the seeds possess non-deep physiological dormancy. The light and temperature experiment was conducted under a constant 4 °C and alternating temperature regimes of 15/6, 20/10, and 25/15 °C (12 h day/12 h night). Seeds were incubated under either 12 h light/12 h dark or continuous darkness (24 h). GA₃ treatment and cold stratification were conducted only at 15/6 °C or 25/15 °C under the 12 h light/12 h dark photoperiod. All seed treatments were incubated for 8 weeks under their respective temperature conditions. To investigate the influence of GA₃, seeds were soaked for 24 h in solutions of 0, 10, 100, or 1000 mg∙L⁻¹ GA₃ and then incubated. Cold stratification was tested by storing seeds at 4 °C for 0, 4, 8, or 12 weeks before incubation. Seeds germinated without additional embryo growth, and no physical dormancy due to seed coat impermeability was observed. No germination occurred at 4 °C. Under light conditions, final germination at 15/6, 20/10, and 25/15 °C was 51.8 ± 1.2%, 28.3 ± 3.5%, and 30.8 ± 2.2%, respectively, while under dark conditions it was 37.0 ± 3.1%, 17.3 ± 2.4%, and 13.5 ± 8.5%, respectively. GA₃ enhanced germination. Without GA₃ treatment, final germination was 41.2% at 15/6 °C and 37.5% at 25/15 °C, whereas with GA₃, final germination reached 100% under both temperatures, regardless of concentration. Cold stratification increased germination, improving both initial and final germination compared to the control. Notably, GA₃ at 1000 mg·L⁻¹ induced rapid and uniform germination under all temperatures, making it the most effective treatment for the propagation of C. denticulatum seeds, and supporting the conclusion that this species exhibits non-deep physiological dormancy.

Plants of the Asteraceae family have been cultivated worldwide for economic, medicinal, and ornamental purposes, including genera such as Aster, Helianthus, and Cosmos. Numerous studies examined their secondary metabolites; however, those of Aster × chusanensis, which is a natural hybrid species in South Korea, are unclear, and optimized propagation methods should be identified. We analyzed phenolic acid concentrations in each part of Aster × chusanensis through HPLC. Further, we investigated the growth characteristics and secondary metabolite concentrations under various growth temperatures using division propagation, followed by growing at 20, 25, and 30 °C in a growth chamber. Chlorogenic acid was the primary compound, which was particularly high in the leaves. The growth characteristics did not differ significantly between temperatures, and 30 °C was most efficient for phenolic acid biosynthesis. Our results provide valuable information on optimized propagation and secondary metabolite concentrations under different temperatures of Aster × chusanensis.

Parasenecio pentaphylla, a new species of the genus Parasenecio from Mt. Ilwol-san, Ilwol-myeon, Yeongyang-gun, Gyeongsangbuk-do, Korea, is described and illustrated here. In Korea, this species has been recognized as P. adenostyloides, known to be a Japanese endemic species. However, it is clearly distinguished from P. adenostyloides by its involucre shape, the number of phyllaries, the number of florets per capitulum, and the ratio of the tube length to the throat length. A molecular phylogenetic analysis using the Internal Transcribed Spacer region also clearly indicated that P. pentaphyllaria was genetically distinct from P. adenostyloides. Therefore, it is recognized as an independent species, different from P. adenostyloides. The specific epithet “pentaphyllaria” was given based on its characteristic of having five phyllaries.

Carex brevispicula (Cyperaceae) is endemic to Korea and is characterized by constricted achenes, short lateral spikes, and awned staminate and pistillate scales. The species classified in sect. Mitratae occurs throughout South Korea, perennating on mountains and/or rocky slopes under half shadow conditions. Meiotic chromosomes of the species were examined in this study, in which 33 meiotic cells from seven populations were found to be less than 2 μm long with non-constricted chromosomes (n = 34II). The stable chromosome number may be related to the narrow geographical distribution and/or distinct achene morphology. Further investigations of the distribution, morphological character variation, and chromosome characteristics should be conducted with closely related taxa to understand the derivation of the species and its endemism in Korea.

Introduction: The chloroplast (cp) is an autonomous plant organelle with an individual genome that encodes essential cellular functions. The genome architecture and gene content of the cp is highly conserved in angiosperms. The plastome of Corydalis belongs to the Papaveraceae family, and the genome is comprised of unusual rearrangements and gene content. Thus far, no extensive comparative studies have been carried out to understand the evolution of Corydalis chloroplast genomes.Methods: Therefore, the Corydalis platycarpa cp genome was sequenced, and wide-scale comparative studies were conducted using publicly available twenty Corydalis plastomes. Results: Comparative analyses showed that an extensive genome rearrangement and IR expansion occurred, and these events evolved independently in the Corydalis species. By contrast, the plastomes of its closely related subfamily Papaveroideae and other Ranunculales taxa are highly conserved. On the other hand, the synapomorphy characteristics of both accD and the ndh gene loss events happened in the common ancestor of the Corydalis and sub-clade of the Corydalis lineage, respectively. The Corydalis-sub clade species (ndh lost) are distributed predominantly in the Qinghai-Tibetan plateau (QTP) region. The phylogenetic analysis and divergence time estimation were also employed for the Corydalis species.Discussion: The divergence time of the ndh gene in the Corydalis sub-clade species (44.31 – 15.71 mya) coincides very well with the uplift of the Qinghai-Tibet Plateau in Oligocene and Miocene periods, and maybe during this period, it has probably triggered the radiation of the Corydalis species.Conclusion: To the best of the authors’ knowledge, this is the first large-scale comparative study of Corydalis plastomes and their evolution. The present study may provide insights into the plastome architecture and the molecular evolution of Corydalis species.

Limestone areas are sedimentary rock outcrops consisting of calcium carbonate created several hundreds of millions of years ago by calcium-secreting marine organisms and subsequently lifted above sea level by tectonic movement. Limestone areas support very high levels of endemic species of plants and are recognized as biodiversity areas with much biological information. The purpose of this study is to devise a strategy for the comprehensive conservation of the vegetation of limestone areas through analyses of the floristics and plant species compositions in ten limestone areas on the Korean Peninsula. The results of 153 field surveys from April of 2010 to October of 2016 identified 1,202 taxa in total, representing 1,096 species, 18 subspecies, 84 varieties, 2 forms, and 2 hybrids in 530 genera and 133 families. Among them, 55 taxa were endemic plants to Korea, and 38 taxa were red data plants. The floristic target plants amounted to 102 taxa, specifically 27 taxa of grade V and 75 taxa of grade IV. In all, 121 alien plants were recorded in the investigated area. Calciphilous plants amounted to 102 taxa, specifically 14 taxa of calciphilous indicator plants, 30 taxa of superlative most calciphilous plants, and 58 taxa of comparative more calciphilous plants. A cluster analysis showed a high degree of similarity between sites that are geographically adjacent with similar habitat environments. Limestone areas also supported groups distinct from those in non-limestone areas, demonstrating the specificity of limestone flora. Plant geography approaches therefore appear to be crucial to gain a better understanding of the level of biodiversity in limestone areas, not only at the interspecific but also at the intraspecific level. These results highlight the importance of protecting limestone habitats to preserve not only their interspecific but also the intraspecific diversity, which is highly threatened.