• Journal of the Korean earth science society
• /
• v.36 no.1
• /
• pp.51-58
• /
• 2015

In order to understand the broad outline and palaeobotanical significances, the fossil woods from the Korean Peninsula were integrated through the literature surveys. Types and diversity of them are gradually increasing from Mesozoic to Cenozoic, especially increased sharply in Cenozoic. During the Early Mesozoic, six conifer taxa belonging to four genera were described, which corresponds to about 6% of the Daedong flora. Those of the Late Mesozoic are all conifers, consisting of fifteen taxa belonging to seven genera, which corresponds to about 29% of the Nakdong flora. During the Neogene, thirty four taxa belong to sixteen families were described. Those woods mostly consist of dicotyledon and have the greatest diversity compared to other geologic eras, which corresponds to about 83% of the Janggi flora. It is inferred that such a rapid increase of the silicified wood fossils in Neogene are due to the abundant presence of dicotyledon in floral composition and of pyroclastic rocks in strata, which are appropriate for preserving wood as fossils.

• Journal of Plant Biotechnology
• /
• v.32 no.2
• /
• pp.135-138
• /
• 2005

Embryogenic callus was obtained from cotyledonary explants of Codonopsis lanceloata on Murashige & Skoog's medium supplemented with 1 mg/L 2,4-D. Suspension cultures of the embryogenic calli were grown on a shaker at 100 strokes/min, and then the calli were subcultured for 2 weeks in 2,4-D-free medium to produce somatic embryo. In somatic embryos at the globular stage, cotyledon initials began to differentiate themselves in the near distal end of the procambial strand. Dicotyledons, tricotyledon, tetracotyledon and fused cotyledon were differentiated from the distal ends of two, three, four and circular procambial strands, respectively. Nearly circular procambial strand in lower hypocotyls were independently differentiated into two, three, four procambial tissues at cotyledonary node and cotyledons to form somatic embryos with dicotyledon, tricotyledon, tetracotyledon. If the distal subepidermal cells of globular embryo exclusively became cotyledon initials, the torpedo or cotyledonary embryo was characterized by somatic embryos with fused cotyledon.

• Korean Journal of Weed Science
• /
• v.8 no.2
• /
• pp.133-140
• /
• 1988

One hundred and one noxious weeds on cultivated land of Taiwan were investigated for the occurrence of "Kranz" leaf anatomy and activities of PEP carboxylase and $C_4$ acid decarboxylating enzymes : NADP-malic enzyme, NAD-malic enzyme, PEP carboxykinase. Based on the leaf anatomy and a/b chlorophyll ratio, twenty-seven species exhibit "Kranz" type leaf anatomy, and seventy-four species were found without it. Among the species investigated, Digitaria radicosa (Presl) Miq., Leptochloa chinensis (L.) Nees, and Sporobolus fertilis (Steud.) W. D. Clayton in the Gramineae were first recorded as $C_4$ plants. Twenty-sven species of "Kranz" type leaf anatomy, include those of monocotyledon ; sixteen species in Gramineae, six species in Cyperaceae. Those of dicotyledon ; two species each in Euphorbiaceae and Amaranthaceae and one species in Portulacaceae. The subtype of fourteen previously uninvestigated species among twenty-seven species were further determined. The properties of the three decarboxylating enzyme from representative species were also characterized.

• Korean Journal of Plant Resources
• /
• v.7 no.1
• /
• pp.53-61
• /
• 1994

This study was carried out in Mt. Backdu which is located at the borderland between Korea and China, to offer the information and help the people who in order to study and utilize the northernresource plants in future. Actually, the exploration and investigation were executed only in china sideof Mt. Backdu and its outskirts.Totally, 100 families, 281 genus and 703 species were investigated. They were classified into 26 spe-cies of pteridophyta, 14 species of gymnospermae, 101 species of monocotyledons and 562 species of di-cotyledons by general taxonomic classification, and 594 medicinal plants(84.5% ), 296 ornamentalplants(38.3% ), 161 edible plants(22.9% ), 92 industrial plants, 67 honey plants and 17 forage plantsby use.

• Journal of Environmental Science International
• /
• v.16 no.11
• /
• pp.1257-1269
• /
• 2007

This study was performed to get more knowledge on the flora and their life form spectrum in the Hallasan Natural Reserve. The vascular plants include 83 species 35 genera 12 families of pteridophytes, 5 varieties 5 species 3 families of gymnosperm, 100 taxa in 2 varieties 98 species 58 genera 8 families of monocotyledon and 362 taxa in 3 forma 10 varieties 349 species 186 genera 65 families of dicotyledon in Hallasan Natural Reserve. The total of vascular plants is 550 taxa in 3 forma 11 varieties 536 species 284 genera 88 families. Among these, 204 species in total including 19 species of pteridophytes, 2 species of conifers, 45 species of monocotyledon and 138 species of dicotyledon are found only in the Hallasan Natural Reserve. The pteridophyte-quotient is 4.52 and floristic richness is 1.94. In the analysis of life form spectrum, there are 190 species (34.5%) of hemicryptophytes and 122 species (22.2%) of geophytes so that two life forms take large portions, 312 species (56.7%) of the vegetation in Hallasan Natural Reserve. Megaphanerophytes and microphanerophytes take 14.5% including 80 species followed by 83 species (15.1%) of nanophanerophytes, 42 species (7.6%) of chamaephytes, 29 species (5.3%) of therophytes, 24 species (4.4%) of hydrophytes and 18 species (3.3%) of epiphytes. According to the life form spectrum hemicryptophytes dominated high portions, which suggests Hallasan Natural Reserve has hemicryptophytic climate and similar to middle parts in the Korean Peninsular. The differences, however, were noticed by that it has more chamaephytes and less therophytes than that of the Peninsular and partially shows the characteristics of artic or subalpine climate.

• Journal of Environmental Science International
• /
• v.17 no.10
• /
• pp.1081-1092
• /
• 2008

This study was conducted to provide scientific information for establishing efficient and systematic measures for nature conservation and management in Manjang-gul lava tube. The number of vascular plants was 204 taxa (82 families, 176 genera, 144 species, 1 subspecies, 26 varieties and 1 forma). Of those, pteridophyte were 5 families, 12 genera, 14 species and 1 variety and gymnosperm were 4 families, 6 genera, 5 species and 1 variety. Seventy three families, 149 genera, 157 species, 1 subspecies, 24 varieties and 1 forma in angiosperm composed of 62 families, 123 genera, 137 species, 1 subspecies, 17 varieties and 1 forma in dicotyledon and 11 families, 26 genera, 20 species and 7 varieties in monocotyledon. The number of naturalized plants was 9 families, 17 genera, 18 species and 3 varieties, totaling 21 taxa.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.3
• /
• pp.25-31
• /
• 1999

The differences in seed germination rates of Korean Native Plants were observed depending on the harvest years, the seed companies, the storage periods, the drying methods and the plant morphological types. The seed germination rates were changed significantly by the harvest years and the seed companies in all 4 species tested. The seed germination rates were decreased after 1 year storage at $4^{\circ}C$ in all 8 species tested and three of them did not germinate at all. A rapid drying method at $35^{\circ}C$ with a convection oven was not suitable for Chrysanthemum spp., but there were no significant changes of germination rates in Aster spp. The germination rates were decreased more at seeding in soil than at lab. test with Dicotyledon but no significant changes with Monocotyledon. Especially, the germination rates of fine seed on 5mm soil covering treatment were significantly decreased.

• Journal of Plant Biotechnology
• /
• v.6 no.2
• /
• pp.91-96
• /
• 2004

The use of liquid-medium-based procedure relative to the solid media led to a 4.5-fold increase in the number of cotyledon-stage embryos. The most efficient system for multiplication and regeneration of somatic embryos was CP6 procedure with the media MSD40/MSD20/MSM6AC/FNL0S3S3GM. However, the rate of regeneration was lower. About 71％ of the embryos with dicotyledon were continued to develop the roots after desiccation treatment and 92％ of the germinated embryos produced shoots in 10 days. Of the four morphologically different types of embryos, dicotyledonous ones showed a high frequency of conversion, while only a few with fused and horn type cotyledon developed shoots. Mature somatic embryos were desiccated in empty petri dishes for 12-72 h. Embryo survival rate was the highest after 12 h of desiccation, but maximal germination was observed at 24 h. After desiccation, they were placed on MS medium without growth regulators for germination. Germinating embryos were transferred to small pots with vermiculite for plant regeneration. The etiolating the plants during the growth was resolved to add 1％ activated charcoal on hormone-free MS medium.

• Journal of Science Education
• /
• v.39 no.3
• /
• pp.376-388
• /
• 2015

The purpose of this study was to develop the experiment-based problem for evaluating scientific ability of elementary scientifically gifted students, and to examine its potential of application for them. The problem for evaluating scientific ability was related to the plant vascular structure of 'the structure and function of plants' unit of elementary school science, and consisted of three components such as observing and inferring, designing an experiment, and concluding. In order to apply for scientifically gifted students, scoring criteria were detailed. For the observing and inferring domain, the arrangement and structure of vascular bundles of the dicotyledon and the monocotyledon, xylem position, reason of putting plants in ink were included. Those of designing an experiment domain were method of dissecting stems of plants, and design experimental procedures, those of concluding were the prediction of experimental results, and comparison and verification with prediction and results. Finally, the scientific ability evaluation problem was applied for 22 scientifically gifted students, who had been taught in the Science Education Institute for the Gifted adjacent University, and we had found the potential of utilization for scientifically gifted students.

• Research in Plant Disease
• /
• v.17 no.3
• /
• pp.265-271
• /
• 2011

Seven phytoplasma diseases have been occurred on floricultural crops in Korea : Ph-ch1 and Ph-ch2 of chrysanthemum, Ph-lily of lily, petunia flat stem-Korean (PFS-K) of petunia, poinsettia branch inducing- Korean (PoiBI-K) of poinsettia, statis witches' broom-Korean (SWB-K) of statis and azalea witches broom (AWB). Classification of the seven phytoplasmal diseases based on 16S ribosomal RNA (rRNA) sequences showed that floricultural crop phytoplasma disease were widespread in order of aster yellow (AY), stolbur and X-disease in Korea. In phenotypic characters, the fasciation was occurred in both monocotyledon plant of lily and dicotyledon plants of petunia and poinsettia. Besides, the fascination was occurred in Ph-lily of stolbur, petunia PFS-K of AY and PoiBI-K of X-disease. This result indicated that phytoplasma classification based on 16S rRNA and symptoms are not consistently related. The comparison of 16S rRNA sequence of the seven floricultural crop phytoplasma with five tree phytoplasmal diseases of jujube witches' broom, paulownia witches' broom, wild jujube witches' broom, mulberry dwarf, golden rain phytoplasma occurred in Korea showed as high as 88.5-99.9% homology. Among them, especially mulberry dwarf showed the highest homology with the seven floricultural crop phytoplasms. Based on this result, floricultural crop phytoplasmas were assumed to be transmitted by insect vectors from tree phytoplasmas in Korea.