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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).

Two newly naturalized plants in Korea: Nuttallanthus canadensis (L.) D. A. Sutton and Lamium purpureum var. hybridum (Vill.) Vill. (한국 미기록 귀화식물: 솔잎해란초와 유럽광대나물)

  • Ji, Seong-Jin;Yang, Jong-Cheol;Jung, Su-Young;Chang, Chin;Park, Soo-Hyun;Kang, Young-Sik;Oh, Seung-Hwan;Lee, You-Mi
    • Korean Journal of Plant Taxonomy
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    • v.42 no.1
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    • pp.91-97
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    • 2012
  • Two naturalized plants belonging to Plantaginaceae and Labiatae are newly recorded for Korean flora. Nuttallanthus canadensis (L.) D. A. Sutton, a taxon of the unrecorded genus Nuttallanthus (Plantaginaceae), was founded in Seogwipo-si, Jeju-do. This species can be distinguished from the Linaria species by its corolla with a pale blue to a pale purple color, a lower lip longer than the upper lip and seed with 4-7 angles when cross-sectioned. Lamium purpureum var. hybridum (Vill.) Vill. was found in Gwangju Metropolitan city, Jeongeup-si, Jeollabuk-do and Gochang-gun, Jeollanam-do. It can be distinguished from L. purpureum L. by its irregularly dentate bracts and upper lips 3-4 mm in length. New Korean names were given, as Sol-lip-hae-rancho to Nuttallanthus canadensis (L.) D. A. Sutton and Eu-reop-gwang-dae-na-mul to Lamium purpureum var. hybridum (Vill.) Vill. In addition, their descriptions, photos, illustrations and keys to related genera and species are provided here.

Aggregated achenes and achene morphology of the Korean Adonis L. and its related taxa in East Asia (한국산 복수초속과 동아시아산 근연분류군에 대한 수과괴 및 수과 형태)

  • Son, Dong Chan;Ko, Sung Chul
    • Korean Journal of Plant Taxonomy
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    • v.43 no.4
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    • pp.312-318
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    • 2013
  • Morphological characters of aggregated achenes, and achene and its epidermal microstructures were observed for 7 taxa belonging to the section Adonanthe of subgenus Adonanthe [A. amurensis Regel et Radde, A. bobroviana Sim., A. davidii Franch., A. multiflora Nishikawa et Ko. Ito, A. pseudoamurensis W. T. Wang, A. ramosa Franch. and A. tianschanica (Adolf) Lipsch. ex Bobrov] and for 1 taxon belonging to the section Lophocarpa of subgenus Adonis (A. aestivalis var. parviflora M. Bieb.). The morphological characters such as shape of aggregated achenes, length of aggregated achenes, shape of achene, and recurved type of persistent style were useful in the classification of the subgenera Adonanthe and Adonis, and each species of the series under section Adonanthe. Epidermal microstructures of achene were grouped into three types according to the presence of microwrinkles and their arranged patterns. These microwrinkles were absent in A. amurensis, were of parallel type in A. bobroviana, A. pseudoamurensis, A. ramosa, and A. aestivalis var. parviflora, and were of parallelperpendicular mixed type in A. davidii, A. multiflora, and A. tianschanica. Also, a new key to them was made using morphological characters of their aggregated achenes and achene.

Taxonomy of the Allium sect. Sacculiferum in Korea: with a special reference to the morphology (한국산 부추속(Allium) 산부추절(sect. Sacculiferum)의 분류: 형태학적 형질을 중심으로)

  • Choi, Hyeok-Jae;Oh, Byoung-Un
    • Korean Journal of Plant Taxonomy
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    • v.33 no.4
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    • pp.339-357
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    • 2003
  • The general morphological characters and chromosome numbers about 7 taxa of Korean Allium sect. Sacculiferum were reviewed. From the results, authors elucidated the key character as well as the range of variations in each taxon, and considered the relationships among taxa in this section. Clear taxonomic treatments also carried out based on the type specimens and the original descriptions. Shape and growing pattern of leaves, size of inflorescences, shape of perianths and tepals, as well as chromosome numbers were key characters in identifying the taxa and in estimating their relationships. On the basis of these characters, A. thunbergii var. thunbergii, A. sacculiferum and A. deltoide-fistulosum were recognised as a distinct species respectively. Hal-la-bu-chu which had been misidentified as A. cyaneum (sect. Reticulato-bulbosa) in Korea was proved to be A. taquetii and belonged to the sect. Sacculi/erum. In addition, A. cyaneum var. deltoides, had been described as a variety of A. cyaneum, was recombined as a variety of A. thunbergii [A. thunbergii var. deltoides (S. Yu, W. Lee et S. Lee) H. J. Choi et B. U. Oh] with the new Korean name of 'Se-mo-san-bu-chu'. In conclusion, Korean sect. Sacculiferum was composed of five species and two varieties. A key to identify the taxa in this section was provided.

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.

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.

Characteristics of Dioscorea alata L. Introduced from Tropical and Subtropical Regions (도입 마(Dioscorea alata L.)의 특성 분석)

  • Chang, K.J.;Yoo, K.O.;Park, C.H.;Park, J.I.;Hong, K.H.;Park, J.H.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.3 no.1
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    • pp.48-69
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    • 2001
  • A lot of clones of the genus Dioscorea have been introduced from some tropical and subtropical regions since 1997. In 33 clones of water yams (Dioscorea alata L.), some morphological characteristics were investigated at the field. Variation ranges of the total weight and tuber number per stump were within the ranges from 90 to 2,147 g with an average of 610 g ; and 1.3-4.7 with an average of 2.8, respectively. The color tones observed on the tuber-flesh were sorted into 3 color-categories, i.e., white, pale brown and pale purple, and those on leaves were sorted into 3 color-categories, i.e., green, heavy green and purplish green. Intraspecific genetic relationship of 19 variation types of the Yam classified by their external morphological characteristics such as leaf and tuber shape was assessed by DNA using random and specific primers. Twenty two out of 113 primers (100 random[10-mer] primers, two 15 mer [M13 core sequence, and (GGAT)4 sequence]) had been used in PCR-amplification. Only 12 primers, however, were successful in DNA amplification in all of the analyzed plants, resulting in 93 randomly and specifically amplified DNA fragments. The analyzed taxa showed very high polymorphisms(69 bands, 71.0%), allowing individual taxon to be identified based on DNA fingerprinting. Monomorphic bands among total amplified DNA bands of each primer was low under the 50%. Similarity indices between accessions were computed from PCR(polymerase chain reaction) data, and genetic relationships among intraspecific variations were closely related at the levels ranging from 0.66 to 0.90.

Morphological Characteristics and URP-PCR Analysis of Hypocrea sp., a Weed Mould of Oyster Mushroom Cultivation (느타리버섯 유해균 Hypocrea sp.의 형태 및 URP-PCR 분석)

  • Seo, Geon-Sik;Kim, Byung-Ryun;Park, Myeung-Soo;Kim, Min-Kyung;Yu, Seung-Hun
    • The Korean Journal of Mycology
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    • v.30 no.2
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    • pp.86-94
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    • 2002
  • Recently a serious outbreak of weed mould caused by a species of Hypocrea occurred in oyster mushroom (Pleurotus ostreatus) substrates in Korea. The disease was characterized by a rapid infestation of the oyster mushroom substrates by Hypocrea sp. and subsequent inhibition of fructification of the mushroom. In spite of it's serious losses to the oyster mushroom industry in Korea, etiology and ecology of the disease have not been studied. Morphological characteristics of the fungus were examined and molecular characteristics of the fungus were compared with those of the green moulds (Trichoderma spp.) isolated from oyster mushroom bed. Stromata formed superficially on suface of the substrates were pulvinate to effuse or irreguler, initially white but becoming yellowish brown, measuring $6.0{\sim}13.0{\times}3.0{\sim}11.0mm$. Perithecia were globose to subglobose, immersed in stroma, $223{\sim}263\;(Ave.239.9){\times}167.3{\sim}231\;(Ave.204.1){\mu}m$ in size. Asci were unitunicate, cylindrical, nonamyloid, $82.7{\sim}124.8\;(Ave.103.3){\times}4.1{\sim}5.1\;(Ave.4.9){\mu}m$ in size, 16 part-spored. Ascospores were bullet-shaped or somewhat oblong, hyaline, bicellular, roughened or warted, $5.4{\sim}7.4\;(Ave.6.5){\times}3.6{\sim}5.5\;(Ave.4.7){\mu}m$ in size. This fungus readily form the stroma on PDA. Mycelia on PDA nearly invisible and without cottony aerial mycelium. Optimum temperature for mycelial growth of this fungus was $25^{\circ}C$ on PDA and its growth rate was 15 mm per day. This species did not grow at below 10 and above $35^{\circ}C$. Phialides in culture enlarged in the middle and aggregated to penicillate type. They were very variable, shorted ampulliform and occasionally curved when matured, but cylinderical when young, measuring $11.9{\sim}24.3\;(Ave.\;14.7){\times}2.9{\sim}3.9\;(Ave.\;3.4){\mu}m$ when matured and $7.2{\sim}14.0\;(Ave.\;10.8){\times}2.8{\sim}4.9\;(Ave.\;3.5){\mu}m$ when young. Phialosopres were ovoid to ellipsoid, smooth, measuring $3.5{\sim}7.2\;(Ave.\;4.5){\times}2.6{\sim}3.3\;(Ave.\;2.9){\mu}m$. Nineteen isolates of Hypocrea sp. were analyzed on the basis of molecular characteristics and classified into phenotypic groups. On the basis of RAPD, URP-PCR, the fungus was confirm to monoclonal, and was classified as a different taxon from reported species of Hypocrea and Trichoderma and supposed to be a new species not previously reported in literature.

Analysis of hybridity of Asplenium castaneo-viride Baker (거미꼬리고사리의 잡종성 분석)

  • Kwon, Yong Ju;Kim, Chul Hwan;Ahn, Jin Kap;Sun, Byung-Yun
    • Korean Journal of Plant Taxonomy
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    • v.39 no.1
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    • pp.12-23
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    • 2009
  • To verify hybridity of Asplenium castaneo-viride, external morphology, spore morphology, anatomy and chromosomes of the species and of the two presumed parental species, A. incisum and A. ruprechtii, were examined. A. castaneo-viride usually had 1-pinnately divided frond. However, some individuals had almost simple fronds with pinnatisect basal parts similar to A. ruprechtii, while others had fronds similar to A. incisum in having oblanceolate blades and basal pinnae with triangular, 2-3 lobed apices. On the surface of the spores, sculpturing consisted of folds that were usually prominent; forming long wings, and irregular or incomplete reticulation. However, reticulation patterns varied among species. A. castaneo-viride showed a wide range of variation from sparse to dense patterns, whereas A. incisum showed only from sparse to intermediate patterns. A. ruprechtii showed from intermediate to dense patterns. The spore size of A. castaneo-viride was $54.63{\mu}m$, larger than other two species ($47.81{\mu}m$ in A. incisum and $44.22{\mu}m$ in A. ruprechtii). The level of undulation of epidermal cell wall was also different. A. incisum had the most shallowly undulated wall, and A. castaneo-viride had a pattern intermediate between the two presumed parental species. This same patterns was recognized in the density of stomata. The density of $45.91/mm^2$ in A. castaneo-viride was intermediate between the two presumed parental species ($67.00/mm^2$ in A. incisum, and $37.86/mm^2$ in A. ruprechtii). Chromosome number was constant (2x =2n = 72) as in A. incisum and A. ruprechtii. However, A. castaneo-viride showed a different ploidy level. The populations of Mt. Mai (Jeonbuk province) and Mt. Duryun (Jeonnam province) were diploid (2n = 72) which is a new record for this taxon, whereas the population of Mt. Buram (Seoul) was tetraploid (2n = 144). Conclusively, A. castaneo-viride was revealed to be a hybrid of A. ruprechtii and A. incisum based on evidence involving leaves, spores, epidermal cells, stomata and chromosome number.