• Title/Summary/Keyword: Taxon

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Endless debates on the extant basal-most angiosperm (현생 기저 피자식물에 대한 끝나지 않는 논쟁)

  • Kim, Sangtae
    • Korean Journal of Plant Taxonomy
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    • v.40 no.1
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    • pp.1-15
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    • 2010
  • Recognizing a basal group in a taxon is one of the most important factors involved in understanding the evolutionary history of that group of life. Many botanists have suggested a sister to all other angiosperms to understand the origin and rapid diversification of angiosperms based on morphological and fossil evidence. Recent technical advances in molecular biology and the accumulation of molecular phylogenetic data have provided evidence of the extant basal-most angiosperm which is a sister to all other angiosperms. Although it is still arguable, most plant taxonomists agree that Amborella trichopoda Baill., a species (monotypic genus and monotypic family) distributed in New Caledonia, is a sister to all other extant angiosperms based on evidence from the following molecular approaches: 1) classical phylogenetic analyses based on multiple genes (or DNA regions), 2) analyses of a tree network of duplicated gene families, and 3) gene-structural evidence. As an alternative hypothesis with relatively minor evidence, some researchers have also suggested that Amborella and Nymphaeaceae form a clade that is a sister to all other angiosperms. Debate regarding the basal-most angiosperms is still ongoing and is currently one of the hot issues in plant evolutionary biology. We expect that sequencing of the whole genome of Amborella as an evolutionary model plant and subsequent studies based on this genome sequence will provide information regarding the origin and rapid diversification of angiosperms, which is Darwin's so called abominable mystery.

Genome size of 15 Lamiaceae taxa in Korea (한국산 꿀풀과 15 분류군에 대한 유전체양 조사)

  • Lee, Yoonkyung;Kim, Sangtae
    • Korean Journal of Plant Taxonomy
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    • v.47 no.2
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    • pp.161-169
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    • 2017
  • The genome size is one of the basic characters of an organism, and it is widely applied in various fields of biology, such as systematics, breeding biology, population biology, and evolutionary biology. This factor was recently highlighted in genome studies because choosing a representative of a plant group having the smallest genome size is important for the efficiency of a genome project. For the estimation of the genome size, flow cytometry has recently been highlighted because it is a convenient, fast, and reliable method. In this study, we report the genome sizes of 15 taxa of Lamiaceae from nine genera distributed in Korea using flow cytometry. Data pertaining to the genome size for all of our species have not been reported thus far, and the data from Agastache, Clinopodium, Elsholtzia, and Isodon are the first reported for each genus. The genome sizes of 15 genera and 39 species were reported to the Plant DNA C-values Database (http://data.kew.org/cvalues/). Scutellaria indica L. has a genome size of 0.37 pg (1C). This is the fourth smallest value among the 98 Lamiaceae taxa in the Angiosperm DNA C-value Database, indicating that this taxon can be used as a reference species in the genome studies in Lamiaceae as a native Korean species. The largest genome size observed in this study is in Phlomis umbrosa Turcz. (1C=2.60 pg), representing the possible polyploidy origin of this species in the family.

Flora of Dongwol Valley in Mt. Gyeryongsan, National Park (계룡산국립공원 동월계곡일원의 식물상 조사연구)

  • Ko Sung-Chu;Kang Shin-Ho
    • Korean Journal of Plant Resources
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    • v.18 no.2
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    • pp.223-239
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    • 2005
  • The vascular plants collected from Dongwol Valley in Mt. Gyeryongsan, national park were composed of all 248 taxa including cultivated species, and classified into 1 phylum, 4 classes, 3 subclasses, 34 orders, 84 families, 178 species, 33 varieties and 4 forms. As compared the flora of the commonly distributing species of this region with those of the southern part, the middle part, the northern part of the Korean Peninsula, Jeju-do Island and Ulreung-do Island, the proportion of them were $90.3\%,\;98.0\%,\;79.0\%,\;73.8\%$ and $62.1\%$, respectively. One taxon of the plants distributed only in the southern part, 3 taxa of those in the middle part, 5 taxa of those in the middle-northern part and 23 taxa of those in the middle-southern part were found in this Valley. Natural resource plants were categorized into edible 118 taxa, medicinal 78 taxa, industrial 46 taxa, ornamental 39 taxa, timber 14 taxa and fiber 9 taxa. Four taxa of the Korean endemic plants are distributed in Dongwol Valley. The vegetation of the valley is Quercus and Rhododendron mixed forest, and it belongs to the boundary between the middle part and the southern part in the floral zone of the Korean Peninsula.

Distribution of woody plants and flora of vascular plant in cheonjiyeon valley in Jeju Island (제주도 천지연계곡의 수목분포와 관속식물상)

  • 김찬수;정은주;송관필;김지은;문명옥;강영제;김문홍
    • Korean Journal of Plant Resources
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    • v.15 no.2
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    • pp.114-122
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    • 2002
  • This study investigated the species composition and distribution of woody plants, and flora of vascular plants of Cheonjiyeon where is located in the most southern region of Korea. Twenty-nine taxa of trees were distributed in the valley, and of these, deciduous broad-leaved trees were 13. Of the total number of 2,547 trees, 1,429 were deciduous broad-leaved trees and remainder was broad-leaved evergreen. Deciduous broad-leaved trees covered 48.7% of the tree canopy while evergreen broad-leaved trees covered only 42.3%. The total number of shrub taxa was 37 with more evergreen shrub taxa than deciduous. Evergreen shrubs occupied 64.4% of shrub canopy while deciduous shrubs covered only 35.4%. The result of the investigation of flora showed that there are 446 taxa of flora including 114 families, 320 genera, 397 species, 1 subspecies, 39 varieties, and 9 forma. Of these, two species, Rubus hongnoensis Nakai and Lycoris chejuensis K. Tae et S. Ko, are endemic plants of Jeju Island. The flora includes 17 taxa of rare plants that are distributed only in Jeju Island in Korea. Also, the flora includes 1 taxon, Elaeocarpus sylvestris (Loureiro) Poiret var. ellipticus (Thunb.) Hara, of Korean natural monument, 2 taxa, Psilotum nudum (L.) Griseb. and Crypsinus hastatus (Thunb.) Copeland, of legally protected wildlife and plants, 38 taxa of naturalized plants, and 75 taxa of introduced plants.

Floristic Study of Mt. Deoktaesan, Jinan, Jeonbuk (덕태산(전북 진안)의 관속식물상)

  • Na, Nu-Ree;Kim, Yoon-Young;Lee, Ga-ram;Song, Hye-In;Park, Jeong-Mi;Jang, Changgee
    • Korean Journal of Plant Resources
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    • v.30 no.4
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    • pp.378-398
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    • 2017
  • Mt. Deoktaesan(1,113 m) is located in Jinan-gun Baekun-myon and Jangsu-gun Chunchun-myon. Investigated area was decided to include Mt. Deoktaesan, Mt. Seongaksan and its neighbor area, and this study was conducted from March to October, 2015 in 12 days. Based on the voucher, vascular plants in Mt. Deoktaesan were 108 families 341 genera 525 species 4 subspecies 64 varieties 14 forms, totally 607 taxa, which is 12.4% of total Korean flora. Korean endemic plants were 15 species. Among these species, Populus tomentiglandulosa T.B.Lee, Campanula takesimana Nakai and Forsythia koreana (Rehder) Nakai are verified as planted species. Rare and endangered plants of designated by Korea Forest Service were 10 taxa, such as Peucedanum hakuunense Nakai, Paeonia japonica (Makino) Miyabe & Takeda, Koelreuteria paniculata Laxmann, Eranthis stellata Maxim., Eranthis stellata Maxim., Viola albida Palib., Chionanthus retusus Lindl. & Paxton, Campanula takesimana Nakai, Tricyrtis macropoda Miq. and Iris ensata var. spontanea (Makino) Nakai, respectively. Phytogeographical special plants were totally 41 taxa, which were grade 17 taxa of garde I, 12 taxa of grade II, 12 taxa of grade III, 8 taxa of grade IV, and 1 taxon of grade V.

On the Debates of Arthropod Phylogeny (절지동물 계통에 관한 논쟁)

  • 황의욱
    • Animal Systematics, Evolution and Diversity
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    • v.18 no.1
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    • pp.165-179
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    • 2002
  • In spite of dramatic change of environmental condition since Cambrian big-bang (explosion occurred ca.540 mya, the phylum Arthropoda retains a great diversity, and it is estimated approximately that 1-10 million arthropod species are extant on the earth. Except for an extinct arthopod subphylum Trilobita, extant arthropods could be divided into five subphyla: Hexapoda, Crustacea, Myriapoda, Chelicerata, and Pycnosonida. During the last century, systematists have disputed about interrealtionships among Arthropoda and its relatives (Onychophora, Tardigrada, and Pentastomida), arthropod phylogenetic position within protostome animals, monophyly or polyphyly of the phylum Arthropods, and interrelationships among five arthropod subgroups (subphyla) etc. Recently, new animal phylogeny was reported that protostomes could be clustered into two groups, Lophotrochozoa and Ecdysozoa, and molting animals such as Nematoda and Arthropoda were included within the Ecdysozoa. On the basis of the new animal phylogeny, first of all, I would mention phylogenetic positions and relationships of Arthropods and its relatives to introduce controversies of arthropod phylogeny in phylum level of animals. After that, I focused mainly on the controveries related to arthropod monophyly and phylogenetic relationships among four major arthropod groups except Pycnogonida. In this work, Pycnogonida which is a relatively small group and one of the five arthropod subphyla was not handled significantly although there are some controversies if it is a sister taxon of chelicerates or the most primitive arthropod group (namely, a sister of four remains arthropod groups).

Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

  • Zheng, You-Kun;Miao, Cui-Ping;Chen, Hua-Hong;Huang, Fang-Fang;Xia, Yu-Mei;Chen, You-Wei;Zhao, Li-Xing
    • Journal of Ginseng Research
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    • v.41 no.3
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    • pp.353-360
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    • 2017
  • Background: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing root-rot of P. notoginseng. Methods: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. Results: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

Distribution of Vascular Plants in Gallasan (Andong-si.Uiseong-gun, Gyeongbuk) (갈라산(경북 안동시.의성군) 관속식물의 분포)

  • Chung, Gyu-Young;Park, Myung-Soon;Nam, Bo-Mi;Hong, Ki-Nam;Jang, Jin;Jeong, Hyung-Jin;Yoo, Ki-Oug
    • Korean Journal of Plant Resources
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    • v.23 no.1
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    • pp.99-114
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    • 2010
  • This study was carried out to clarify the distribution of vascular plants and their usefulness at Gallasan of Andong-si in Gyeongbuk (596.2 m, N $36^{\circ}29'396"{\sim}36^{\circ}29'356"$, E $128^{\circ}43'841"{\sim}128^{\circ}45'799"$). The vascular plants collected 13 times (April 2006 to August 2009) were consisted of total 424 taxa; 92 families, 273 genera, 365 species, 2 subspecies, 47 varieties and 10 forms. Among them, edible, medicinal, industrial, ornamental and unknown of usefulness plants were 239 taxa, 291 taxa, 109 taxa, 135 taxa, 24 taxa, respectively. Korean endemic plants of this area were 9 taxa, and Law-protected plants by Ministry of Environment were 2 taxa, and the special plants species based on floral region by Ministry of Environment were 7 taxa in grade III category, 1 taxa in grade IV category, 5 taxa in grade V category, rare plants were 1 taxon in critically endangered (CR), 3 taxa endangered species (EN), 2 taxa vulnerable (VU), the naturalized plants were 23 taxa.

Evaluation of Various Oligotrophic Media for Cultivation of Previously Uncultured Soil Bacteria (난배양성 토양세균의 배양법 평가 및 신 분류군의 순수분리)

  • Kim, Do-Hyoung;Lee, Sang-Hoon;Cho, Jae-Chang
    • Korean Journal of Microbiology
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    • v.44 no.4
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    • pp.352-357
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    • 2008
  • We evaluated cultivation methods to obtain pure cultures of previously uncultivated bacteria from soil. Soil bacteria (suspensions) were inoculated onto various oligotrophic media with one of the following additives: 1) soil extract; 2) anthraquinone disulfonate (humic acid analogue); 3) acyl homoserine lactones (quorum-signaling compounds); 4) catalase (for the protection of bacteria from exogenous peroxides). After the relatively long period (60 days) of incubation with elevated concentrations of $CO_2$ (5%, v/v), the media containing catalase showed the highest colony count. We purified 147 randomly selected colonies from the media and the isolates were subjected to the phylogenetic analyses of their 16S rRNA gene sequences. Phylogenetic analysis revealed that approximately 30% of the isolates might belong to novel species or novel family, suggesting that the media and incubation conditions used could be useful for the cultivation of as-yet-uncultured bacteria. Especially, bacteria belonging to the phylum Acidobacteria, ubiquitous bacterial taxon known as an uncultured bacterial group (at least difficult to culture from environmental samples), were successfully cultured in this study.

Phylogenetic Study of Genus Sorbus in Korea by Internal Transcribed Spacer Sequence (ITS) (ITS에 의한 한국내 마가목 속 분류군의 유전적 계통분류학적 연구)

  • Huh, Man-Kyu;Kim, Sea-Hyun;Park, So-Hye
    • Journal of Life Science
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    • v.17 no.12
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    • pp.1610-1615
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    • 2007
  • Genus Sorbus is a long lived woody species that is primarily distributed throughout Asia and Europe. This species is regarded as very important herbal medicines in Korea and China. Sorbus commixta is primarily distributed throughout Europe. We evaluated a representative sample of the four taxa with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within genus. Aligned nucleotide sequences of the length of ITS1 were nearly constant within genus Sorbus varying from 219 in S. aucuparia to 218 in the rest species. Especially, the 5.8S subunit of all taxa of Sorbus was found to constant of 165 bp nucleotides. However, aligned nucleotide sequences of the length of ITS2 vary from 240 in S. sambucifolia var. pseudogrcilisto 245 in S. aucuparia. Total alignment length is 629 positions, of which 35 are parsimony-informative, 32 variable but parsimony-uninformative, and 552 constant characters. The base furtherance showed the difference to the by a total taxon: an average A and T are 17.7% and G and C are 30.4%, 34.2%, respectively. All the four taxa beginning with conserved base paired triplets emerging from single strand regions (domain I). Noteworthy, in the RNA secondary structure proposed for the three Korean Sorbus taxa RNA transcript ITS2, which shows a remarkedly well-conserved folding (domain II). When compared to the European Sorbus (S. aucuparia) of ITS2. ITS analysis may be useful in germ-plasm classification several taxa of genus Sorbus.