• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.32-32
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• 2019

The aim of this study was to provide basic guidelines for conservation and management of endangered plants in the national parks of Korea. Iris dichotoma Pall. (Iridaceae), which is a popular garden plant, is considered a second-class endangered species by Korean government and it is listed as a EN (Endangered) species in Red Data Book of Korea. We analyzed ecological conditions of I. dichotoma habitats based on vegetation properties and soil characteristics. This species which is known to inhabit in grassland adjacent to the ocean of lowlands slope and its population was located at an elevation of 8 m to 11 m. In the study sites, the mean of soil organic matter, total nitrogen and soil pH were 6.16%, 0.234% and 5.39 respectively. Additionally, the genetic variation and structure of three populations were assessed using ISSR (Inter Simple Sequence Repeat) markers. The genetic diversity of I. dichotoma (P = 59.46%, H = 0.206, S = 0.310) at the species level was relatively high. Analysis of molecular variance (AMOVA) showed 82.1% of the total genetic diversity was occurred in within populations and 17.9% variation among populations. Lastly, we developed predicted distribution model based on climate and topographic factors by applying SDMs (Species Distribution Models). Consequently, current status of I. dichotoma habitats is limited with natural factors such as the increase of the coverage rate of the herbs due to ecological succession. Therefore, it is essential to establish in situ and ex situ conservation strategies for protecting natural habitats and to require exploring potential and alternative habitats for reintroduction.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.182-188
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• 2012

Iris dichotoma Pall. is an important endangered plant belonging to the family Iridaceae. A method was developed for the rapid micropropagation of I. dichotoma through plant regeneration from leaf, rhizome, and root explant-derived calli. Leaf, rhizome, and root segments were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D; $0-3.0mg{\cdot}L^{-1}$) for callus induction. Callus production was highest at $1.0mg{\cdot}L^{-1}$ 2,4-D, where 73.8% and 45.5% of cultured rhizome and root cuttings, respectively, produced calli. The viable calli were maintained at an induced concentration of 2,4-D ($3.0mg{\cdot}L^{-1}$). They were then transferred to MS medium supplemented with various concentrations of 2,4-D ($0-3.0mg{\cdot}L^{-1}$) in combination with 6-benzyladenine (BA: 0, 1.0 and $3.0mg{\cdot}L^{-1}$) for adventitious shoot regeneration. The addition of a low concentration of 2,4-D into BA-containing medium significantly increased the frequency of shoot regeneration in leaf, rhizome, and root-derived calli. The highest number of adventitious shoots (26.4 per callus) formed at $0.5mg{\cdot}L^{-1}$ 2,4-D and 1.0 mg/l BA. For rooting of the shoots, half- strength MS medium supplemented with different concentrations of indole 3-butyric acid (IBA) $0-3.0mg{\cdot}L^{-1}$ was tested. The optimal results were observed using half-strength MS medium supplemented with $1.0mg{\cdot}L^{-1}$ IBA, on which 98% of the regenerated shoots developed roots with an average of 3.5 roots per shoot within 45 days. The plantlets raised in vitro were acclimatized and transferred to soil with 95% success. This in vitro propagation protocol will be useful for conservation and mass propagation of this endangered plant.

• Journal of Environmental Science International
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• v.14 no.3
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• pp.265-269
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• 2005

This study was carried out to provide the basic data for an identifying system for Iris species distributed in Korean market from complete analysing of genetic relationship between three native Iris species and one cultivar bred from the native Iris plant. RAPD analysis of genetic relationship among 4 Irises was possible. According to the RAPD analysis, they were divided into two groups. Among 4 Irises used in this study, Iris laevigata 'Veriegata', Iris laevigata and Iris setosa were classified into the same group since they had many similarities even though the habitat of Iris laevigata in Korean peninsular is restricted mainly in the south and Iris setosa is naturally inhabited in the northern part of Kangwondo. The value for the dissimilarity index of Iris laevigata and Iris laevigata 'Veriegata' was 6.757. The value for the dissimilarity index of Iris laevigata and Iris dichotoma was 95.000, so that they were genetically the farthest among them since the genetic relationship between two species are separated far if the value of the dissimilarity index is close to 100.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.401-405
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• 2004

Karyotypes were established in the eight Korean native species of the genus Iris. Chromosome numbers were 2n=50 in I. koreana and 2n=42 in I. uniflora var. carinata and their karyotype formulas were K = 2n = 50 = 14m + 28sm + 8st and K = 2n = 42 = 16m + 26sm, respectively. I. dichotoma and I. pseudoacorus were diploids of 2n=34. However, they showed different karyotype formulas: K = 2n = 34 = 26m + 6sm + 2st in I. dichotoma and K = 2n = 34 = 8m + 24sm + 2st in I. pseudoacorus. I. setosa, and I. pallasii var. chinensis carried the same chromosome numbers of 2n=40, but they showed different patterns of karyotype formula: K = 2n = 40 = 22m + 14sm + 4st in I. setosa and K = 2n = 40 = 26m + 12sm + 2st in I. pallasii var. chinensis. I. sanguinea was a diploid of 2n=28 and the karyotype formula was K = 2n = 28 = 14m + 14sm. I. ensata var. spontanea was a diploid of 2n=24 and the karyotype formula was K = 2n = 24 = 10m + 14sm. Each species showed characteristic chromosome composition with a pair of satellite chromosome except I. koreana with three pairs of satellite chromosomes. The chromosomes of I. dichotoma and I. uniflora were comparatively short, while the chromosomes of I. ensata were remarkably bigger than those of other species. These cytological data will give a useful information for the identification and breeding program of the Iris plants.

• Korean Journal of Plant Taxonomy
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• v.53 no.1
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• pp.1-8
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• 2023

Sustainable habitats play a significant role in determining the survival and habitat preservation of endangered species. To conserve the endangered species Iris dichotoma Pall. and its habitat in Taeanhaean National Park, we collected seeds from a natural population and germinated and propagated them in a greenhouse. In 2019, the propagated individuals of I. dichotoma were transplanted at two study sites in Taeanhaean National Park. After conservation translocation, annual monitoring was conducted from 2020 to 2022, and factors related to the survival and growth of I. dichotoma (clonal propagation rate [%], the flowering rate [%], the population density [individual/m²], the maximum leaf bundle length [height; cm], the maximum leaf bundle width [cm], and the pedicel length [cm]) were measured. According to the results of the monitoring of the flowering and fruiting periods for three years after transplantation, 82.4% of individuals in total were found to have survived. During 2020 to 2022, the mean population density (individual/m²) increased from 0.36 to 0.42 and the size of the leaf bundle length and the width both decreased compared to the corresponding figures in 2019 (p < 0.05). According to the findings here, the transplanted population of I. dichotoma is considered to have adapted successfully to its new site in Taeanhaean National Park.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.60-66
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• 2015

This study was conducted to determine the effects of seed storage method ($-20^{\circ}C$, $2^{\circ}C$ dry, $2^{\circ}C$ wet 30 days, $2^{\circ}C$ wet 60 days, stratification and room temperature) and shading treatment(control, 50%, 80%) on seed germination, seedling growth of endangered species, Iris dichotoma and Iris setosa. As a result, seed germination rate of I. dichotoma was the highest at 75% when seed were stored at $2^{\circ}C$ wet 60 days and then sown under non-shading condition. The seed of I. dichotoma belong to intermediate seed. Seed germination rate of I. setosa was the highest at 95% when seed were stored at $2^{\circ}C$ wet 60 days and then sown under 80% shading condition. The seed of I. setosa belong to recalcitrant seed. Seedlings of I. dichotoma and I. setosa showed not only the best seedling quality but also seedling vigor index in seed stored at $2^{\circ}C$ wet 60 days under non-shading condition, with the growth characteristics of plant height (6.4, 7.2 cm), number of leaves (3, 4), leaf width (4.6, 3.2 mm), leaf length (5.7, 6.8 cm), fresh weight (aerial/root part; 144/260, 97/153 mg), dry weight (aerial/root; 31/20, 17/17 mg) and seedling vigor index and modified seedling vigor index (13,895/9,479, 13,256/8,668). In this research, I. dichotoma and I. setosa seed were stored at $2^{\circ}C$ wet 60 days, and then sown in non-shading condition, seed germination rate was more than 75%, 90%, respectively, and production of superior quality seedlings.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.229-234
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• 2021

Iris dichotoma Pall. found on Daechung Island in Korea has been designated as an endangered species. To aid in conservation efforts of this species, this study investigated its germination characteristics and seed dormancy type. Four sets of seeds were incubated at different temperatures (4/1℃, 15/6℃, 20/10℃, and 25/15℃). One set of seeds was cold stratified (4 weeks at 4/1℃). The final germination rate and mean germination time showed that the optimal germination temperature was 25/15℃. Final germination rates were ~70%, showing no significant difference among temperature treatments. However, mean germination time were significantly different among all temperature treatments except for 4/1℃. Mean germination time for seeds with temperature treatments of 15/6℃, 20/10℃, and 25/15℃ were 3.2, 2.1, and 1.5 weeks, respectively. At 25/15℃, the mean germination time was half of that at 15/6℃. Seeds of I. dichotoma had fully developed embryos at the time of dispersal. No additional growth of the embryo was observed. Cold stratification did not affect the final germination rate or the mean germination time. This study shows that seeds of I. dichotoma have no physiological or morphological dormancy, unlike other members of the Iris genus known to have seed dormancy that needs a relatively high incubation temperature (≥25/15℃) for mass propagation to occur. These results will be useful for understanding ecophysiological mechanisms related to the species' habitat. They are also useful for mass propagation of I. dichotoma for the purpose of conserving this endangered species.

• Korean Journal of Plant Taxonomy
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• v.43 no.3
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• pp.227-235
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• 2013

Molecular phylogenetic studies were conducted to evaluate taxonomic identities and relationships among 16 species of the korean genus Iris L. Korean Iris was grouped by five clades. Series Laevigatae, Tripetalae, Laevigatae and Sibiricae was included to Clade I. Series Chinensis, and Easatae was composed to Clade II. Series Chinensis was included to Clade III. Series Chinensis was composed to Clade IV. Series Crossiris, Pumilae and Pardanthopsis was included to Clade V. Iris dichotoma, I. mandshurica and I. tectorum formed one clade, and it was located mostly in the basal group. I. minutiaurea and I. koreana was not formed independent clade, so it is not clear between them about taxonomic identities. Iris tectorum was established taxonomic system by Series Cossiris in Subgenus Crossiris. Series Chinensis (I. odaesanensis, I. minutiaurea, I. koreana, I. rossii var. latifoia, and I. rossii) was distinguished is clear by Series Chinensis (I. odaesanensis, I. minutiaurea and I. koreana) and Series Chinensis (I. rossii var. latifoia and I. rossii). The Genus Iris was divided into four subgenus (Limniris, Crossiris, Iris and Pardanthopsis). We thought that evolved to subgenus Limniris in subgenus Crossiris, iris and Pardanthopsis.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.39-43
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• 2006

A detailed karyotype analysis was carried out in five Korean native Iridaceae species; Iris pseudoacorus, I. pallasii. var. chinensis, I. tectrum, I. dichotoma and Belamcanda chinensis. Chromosome compositions of the five species showed that they have different karyotypic formulae; I. pseudoacorus 2n=34=10m+16smn+8st including two pairs of satellite chromosomes, I. pallasii var. chinensis 2n=40=26m+12sm+2st including two pairs of satellite chromosomes, I. tectrum 2n=30=14m+16sm including five pairs of satellite chromosomes, I. dichotoma 2n=32=22m+10sm including two pairs of satellite chromosomes, and B. chinensis 2n=32=20m+10sm+2st including one pair of satellite chromosomes. These results will supplement the previous cytogenetic reports in Iridaceae species and enhance our understanding on the genetic structure, which will be useful in clarifying the unique characteristics of each species for practical breeding programs for horticultural and pharmaceutical purposes.

• Journal of Ecology and Environment
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• v.42 no.1
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• pp.1-11
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• 2018

Background: In the study, the effects of elevated $CO_2$ and temperature on the nitrogen content, carbon content, and C:N ratio of seven rare and endangered species (Quercus gilva, Hibiscus hambo, Paliurus ramosissimus, Cicuta virosa, Bupleurum latissimum, Viola raddeana, and Iris dichotoma) were examined under control (ambient $CO_2$ + ambient temperature) and treatment (elevated $CO_2$ + elevated temperature) for 3 years (May 2008 and June 2011). Results: Elevated $CO_2$ concentration and temperature result in a decline in leaf nitrogen content for three woody species in May 2009 and June 2011, while four herb species showed different responses to each other. The nitrogen content of B. latissimum and I. dichotoma decreased under treatment in either 2009 and 2011. The leaf nitrogen content of C. virosa and V. raddeana was not significantly affected by elevated $CO_2$ and temperature in 2009, but that of C. virosa increased and that V. raddeana decreased under the treatment in 2011. In 2009, it was found that there was no difference in carbon content in the leaves of the six species except for that of P. ramosissimus. On the other hand, while there was no difference in carbon content in the leaves of Q. gilva in the control and treatment in 2011, carbon content in the leaves of the remaining six species increased due to the rise of $CO_2$ concentration and temperature. The C:N ratio in the leaf of C. virosa grown in the treatment was lower in both 2009 and 2011 than that in the control. The C:N ratio in the leaf of V. raddeana decreased by 16.4% from the previous year, but increased by 28.9% in 2011. For the other five species, C:N ratios increased both in 2009 and 2011. In 2009 and 2011, chlorophyll contents in the leaves of Q. gilva and H. hamabo were higher in the treatment than those in the control. In the case of P. ramosissimus, the ratio was higher in the treatment than that in the control in 2009, but in 2011, the result was the opposite. Among four herb species, the chlorophyll contents in the leaves of C. virosa, V. raddeana, and I. dichotoma did not show any difference between gradients in 2009, but decreased due to the rise of $CO_2$ concentration and temperature in 2011. Leaf nitrogen and carbon contents, C:N ratio, and chlorophyll contents in the leaves of seven rare and endangered species of plant were found to be influenced by the rise and duration of $CO_2$ concentration and temperature, species, and interaction among those factors. Conclusions: The findings above seem to show that long-term rise of $CO_2$ concentration, and temperature causes changes in physiological responses of rare and endangered species of plant and the responses may be species-specific. In particular, woody species seem to be more sensitive to the rise of $CO_2$ concentration and temperature than herb species.