• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.224-229
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• 1996

Floral flavonoids of Hibiscus syriacus L. six complex with 68 formac all in all were examined. Thirteen flavonoids appeared on the two dimensional chromatogtams. Spot 5, however, occupied more than 50% in total flavonoid contents, and other spots were invariably minor pigments in all samples examined. Ten spots among 13 spots showed the characteristics of flavones, having color of purple to dark purple under UV light and yellow under ammonia gas, while spots reagents suggests that 10 purple spots are 4', 5-OH aglycone type. Four spots out of 10 purple spots were possible to be identified: spot 5, saponarin, spot 7, vitexin, spot 9, xylovitexin, and spot 11, rhamnosylvitexin, respectively. It was suggested that spot 13 might be apigenin-7-O-diglycoside.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.171-177
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• 2008

Variations in antioxidant capacity of leaves and characteristics of seed germination among five Hibiscus hamabo populations in Korea were evaluated. While the leaves of H. hamabo from Shincheon contained highest Na concentration, those from Hado and Ohzo does lowest. MDA content and SOD activity didn't show significant difference among populations, but total protein and anthocyanin content were significantly different among five populations. The filled seed rates of five populations were ranged from 92.0 to 98.7%, and the moisture contents of seeds from Shinyang and Soando were lower than that of R. syriacus (5.18%). The fresh weights of H. hamabo from Hado and Ohzo were the highest and those of seeds from Shinyang and Soando were the lowest. Significant variations among H. hamabo populations were detected for all seed germination characters: percentage of germination, average germination time and germination rate and uniformity. SOD activities of seeds from Onpyoung and Soando were the highest of five populations, and total protein concentrations of seeds in Ohzo and Shinyang populations were higher than those of other populations. H. hamabo is considered exposed to salt stress and all characteristics of seed germinations were inferior to other species.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.25-32
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• 2016

A severe outbreak of gray mold on kenaf (Hibiscus cannabinus L.) was observed on kenaf grown in the research field of Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Korea in 2014. Gray mold appeared on young plants as gray-brown velvety mold covering stems and leaves. Infections that girdled the stem caused wilting above the infected area and developed a canker. The casual fungus formed grayish brown colonies on potato dextrose agar. The conidia were one celled, mostly ellipsoid or ovoid in shape, colorless or pale brown in color, and 6-18 × 4-10 ㎛ in size. The conidiophores were 15-32 ㎛ in length. These measurements and taxonomic characteristics were most similar to those of Botrytis. DNA sequencing and phylogenetic analysis of the complete internal transcribed spacer rRNA gene region confirmed that the fungal isolates were indeed Borytis cinerea. Koch's postulates were supported by pathogenicity tests conducted on healthy plants. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Botrytis cinerea. To the best of our knowledge, this is the first report of a gray mold caused by B. cinerea on kenaf in Korea.

• Korean Journal of Plant Taxonomy
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• v.53 no.2
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• pp.148-156
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• 2023

Hibiscus hamabo (Malvaceae) is a deciduous shrub mainly found in northeast Asia, including China, Japan, and Korea. Due to its limited distribution on Jejudo Island and at several sites in Jeollanam-do in Korea, H. hamabo has been designated as an endangered species by the Ministry of the Environment and has been the subject of several restoration programs. In this study, we quantified genetic variations using double-digestion restriction-associated DNA sequencing technology in 96 individuals of H. hamabo from 13 distinct populations in Korea. We determined 3,352 genome-wide single nucleotide polymorphism loci after stringent filtering processes and analyzed the level of genetic variation within and among populations as well as the population differentiation and genetic ancestry with various assumptions pertaining to the population origin. Our results indicated weak differentiations among populations surveyed in this study but clearly suggested that most of the H. hamabo populations maintain a relatively high level of genetic diversity as evidence of frequent genetic exchanges among populations via outcrossing or sequential gene flows. For a more detailed analysis of the origin of Korean H. hamabo and its demographic history, it will be necessary to expand sampling in China and Japan.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.92-92
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• 2022

Under the COVID-19 pandemic, interest in immune enhancement is increasing. Although the immune-enhancing activity of plants of the genus Hibiscus has been reported, there is no study on the immune-enhancing activity of H. syriacus. Thus, in this study, we investigated the immune-enhancing activity of Hibiscus syriacus leaves (HSL) in mouse macrophages, RAW264.7 cells, and immunosuppressed mice. HSL increased the production of immunostimulatory factors such as nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) and activated the phagocytosis in RAW264.7 cells. The HSL-mediated production of immunostimulatory factors was dependent on toll-like receptor 4 (TLR4), p38, and c-Jun N-terminal kinase (JNK) in RAW264.7 cells. In the immunosuppressed mouse model, HSL increased the spleen index, the levels of the cytokines, and the numbers of lymphocytes, neutrophils, and monocytes. Taken together, HSL may be considered to have immune-enhancing activity and be expected to be used as a potential immune-enhancing agent.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.55-55
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• 2021

Hibiscus hamabo is a deciduous shrub that grows around salt marshes and is considered a semi-mangrove plant found in Asia. There are no studies on the biological activity of H. hamabo except for studies on the anthocyanin content. We investigated the anti-inflammatory effects of H. hamabo extract (HHE) on lipopolysaccharide (LPS)-induced RAW 264.7 cells. As nuclear factor-kappa B (NF-kB) induced by LPS moves into the nucleus, inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and inflammatory cytokines are promoted and the inflammatory reaction begins. The nitric oxide (NO) production decreased by the treatment of HHE. Moreover, mRNA levels of inflammation-related cytokines, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β, were significantly suppressed by HHE. Similarly, the expressions of iNOS and COX-2 were also decreased. The phosphorylation of p65, a subunit of NF-κB, was suppressed by HHE. As a result, HHE can be used as an effective natural material for the anti-inflammatory agent.

• Korean Journal of Plant Taxonomy
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• v.37 no.2
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• pp.115-129
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• 2007

Using internal transcribed spacer (ITS) sequences and inter-simple sequence repeats (ISSRs) data, genetic diversity of a rare species, Hibiscus hamabo Siebold & Zucc. was examined for 3 populations in Jeju Island, Korea. A total of 14 nucleotide (excluding 3 ambiguous nucleotide) site variation in the ITS was observed from 18 individuals (Population 1, Hadori), which differed up to 13 bp in pair-wise comparison. On the contrary, the ITS sequences of all individuals in Populations 2 and 3 were identical. Genetic diversity estimates including Nei's gene diversity (h) generated by ISSR data were substantially high in Population 1 compared to other two populations. Low genetic variation in Populations 1 and 2 is considered due to genetic drift (bottleneck effect) and limited gene flow in these populations. Considering the differences in genetic diversity, protection of the Population 1(Hadori) is very critical for in situ conservation of Hibiscus hamabo in Korea. If ex situ conservation is required, making the full use of Population 1 will be most efficient.

• The Korean Journal of Soil Zoology
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• v.9 no.1_2
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• pp.1-5
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• 2004

Insect pests and their natural enemies of Hibiscus Linne (Malvaceae) were investigated from March 2002 to November 2004. Fourteen insect pest species of 9 families in 5 orders were collected from Hibiscus syriacus: 5 species in Homoptera, 3 species in Lepidoptera, 2 species in Coleoptera, 1 species in Orthoprera, 1species in Hemiptera, 1 spedies in Acarina, and 1 species in Stylommatophora. Especially, Aphis gossypii Glover (Aphididae), Anomis megogona Walker(Noctuidae) and Tetranychus urticae Koch (Tetranychidae) were very important species because of their increasing daminge. The highest donsities were observed from May to June in August in Tetranychus urticae. As the enemies and ento-mopathogens of insect pests on Hibiscus syriacus, 1 species of bacteria, 3 species of fungi, 1 species of fungi, 1 species of Hemiptera, 1 species of Coleoptera, 2 species of Hymenopetera, 2 species of Diptera, and 1 species of Acarina were investigated. As the predators and parasitoids of Aphis gossypii, Aphidoletes aphidoletes aphidimyza Rondani (Cecidomyiidae), Meliscaeva cinctella Zetterstedt (Syrphidae), Harmonia axyridis Pallas (Coccinellidae), and Aphidius gifuensis Ashmead (Braconidae), entomopathogenic fungi, Vericillium lecani naturalis strain (Moniliaceae) and Beauveria bassiana naturalis strain strain (Hypocreaceae) were observed and Bacillus thuringiensis naturalis strain (Bacillaceae), B. bassiana, Metarhizium anisopliae naturalis strain (Hypocreaceae), predators of Tetranychus urticae, Amblyseius sp. (Phytoseiidae), and Orius sp. (Anthocoridae) were observed.

• Journal of Naturopathy
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• v.10 no.1
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• pp.42-47
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• 2021

Purpose: This study investigated the antioxidant activities of water extracts from Hibiscus petals, Moringa oleifera gymnosperm, and Nipa fruticans wurmb. Also, the possibility of their use as a functional cosmetic material and food were searched. Methods: We extracted Hibiscus petals, M. oleifera gymnosperm, and N. fruticans wurmb with water. And then, we measured the content of total polyphenols and flavonoids and the ability to scavenging free groups of ABTS and DPPH to study the antioxidant function. The toxicity of samples evaluated by measuring cell viability. Results: The polyphenol content of the water extract of N. fruticans wurmb was 109 ㎍/mg, which was significantly higher than that of Hibiscus petals (13 ㎍/mg) and M. oleifera gymnosperm (19 ㎍/mg). Radical scavenging ability was also excellent in N. fruticans wurmb, and the cytotoxicity test results of the samples were similar. Conclusions: The water extracts showed antioxidant activity to use for cosmetic materials or natural healing foodstuff.

• Journal of Plant Biology
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• v.38 no.1
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• pp.95-105
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• 1995

Complete microsporogenesis of Hibiscus syriacus L. were carried out employing LM, TEM, and SEM to investigate the pollen ontogeny that undergoes considerable structural differentiation. The process first began with several cell diYisions in the anther primordium that produces 3 different tissues of epidennal, archesporial, and connective tissues. Only archesporial tissue involved further differentiation into the tapetum and formation of reproductive cells, pollen mother cells (PMC). The tapetum and PMC were closely associated with each other structurally and metabolically by exhibiting numerous plasmodesmata, mitochondria, and many small vacuoles in their dense cytoplasm. A callosic wall began to surround the PMC while meiosis took place in the PMC to produce 4 microspores. When thick callose encircled each microspore as a frame, the sporodenn development initiated from the plasma membrane of a pollen grain in a tetrad. The first fonned sporoderm layer was bacules and tectum of sexine that originated from the plasma membrane. After the dissolution of a callose, further development Qf sporoderm continued in the order of nexine 1, nexine 2, and intine layer. The nexine layer was thicker (ca. $2-3.5\;\mu\textrm{m}$) than the intine layer whose thickness was about $0.9-1.5\;\mu\textrm{m}$. Upon completion of the sporoderm development, that is after intine formation, spines and apertures of pollen surface ornamentation initiated from the tectum. Spines were dimorphic, about $4-9\;\mu\textrm{m}\;an;15-20\;\mu\textrm{m}$ in length, and no basal cushion was detected. The mature pollen grains ranged $100-200\;\mu\textrm{m}$ in diameter, but their average was about $170\;\mu\textrm{m}$. About 120 spines were observed over the spheroidal pollen surface. Apertures were simple punctures of $2-3\;\mu\textrm{m}$ in diameter and about 50 apertures were arranged somewhat helically over the surface. Comparing such features of form and size of the pollen, sporodenn sculpture and structure, and aperture and spine conditions with known evolutionary trends in the genus Hibiscus, Hibiscus syriacus seemed to possess many advanced features in the sporodenn differentiation.iation.