• 한국해양학회지
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• v.27 no.4
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• pp.268-276
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• 1992

Multitrophic interactions among gelatinous planktivores, zooplankton, and phytoplankton were in vestigated in Reeves Bay. New York from mid-March to July in 1989 to evaluate the top-down effect by gelatinous macrozooplankton on the Gyrodinium aureolum bloom through cascading tropic interactions. Zooplankton abundances reached maximal density following a decrease in gelatinous macrozooplankton (hydromedusae and scyphomedusae) abundances, and phytoplankton biomass was low at this time. Subsequently, as ctenophore populations increased zooplankton abundances decreased sharply, and the cell concnetration of G. aureolum began to increase. This field observation supports that the top-down control by gelatinous macrozooplankton on grazers, resulting in low grazing pressure on phytoplankton, can cause an algal bloom. The minimal zooplankton grazing measured using /SUP 14/C tracer technique during the bloom period indicated that zooplankton did not prefer G. aureolum as a good source.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.483-487
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• 2016

The damage of citrus fruits caused by Scirtothrips dorsalis Hood has being increased in Jeju, Korea. The seasonal abundance of S. dorsalis and its injury symptoms in citrus orchards have been studied since the endemic outbreak in Jeju, but studies for the occurrence pattern of S. dorsalis in citrus orchards influenced by adjacent primary hosts have not been fully conducted yet. We selected kiwi- and mango-citrus adjacent orchards to study the migration pattern of S. dorsalis toward to citrus orchards. Yellow-colored sticky traps were used for monitoring the seasonal abundance of S. dorsalis and their migration pattern in two orchards. In citrus orchards, also, we placed sticky traps at 0, 5, 10, 15 and 20 m apart from the border of kiwi orchard, and 0, 7 and 20 m apart from the border of mango orchard. The seasonal occurrence pattern of S. dorsalis caught on sticky traps were similar between two adjacent orchards. However, the abundances in kiwi or mango orchard was much higher than those of citrus. Also, it was found that densities, distribution and damage of S. dorsalis in citrus orchards depend highly on the distance from the border of kiwi and mango orchards. This result suggested that the primary hosts such as kiwi and mango plants influence the occurrence of S. dorsalis in adjacent citrus orchards. And this information may provide a basic direction for establishing the management strategy of S. dorsalis in citrus orchards.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.281-284
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• 2009

Seventy two species of armored scale have been recorded from the Korean peninsula since late 1920s. Nine of these species were obtained from greenhouses. Of these 9 armored scale species, 7 species are considered to have failed to colonize fields or greenhouses and 2 species, which were collected from pineapple plants, Tillandsia plants and cactus trees in greenhouses, were never taken from the exterior environment.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.200-206
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• 2003

This study were conducted to assess plant­parasitic nematodes infesting Codonopsis lanceolata. Ten kinds of plant­parasitic nematode gem including Meloidogyne and Pratylenchus were identified in 34 localities of C. lanceolata fields in three provinces in Korea. Meloidogyne, a dominant genus, was found in 97％ localities and showed high average density as 1,700 nematodes per 300$m\ell$ soil. Its average density was 10 times higher in upland field than in paddy field.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.479-484
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• 2000

This study was conducted to examine the effects of explant sources and plant growth regulators on mass propagation of Cyclamen persicum. Tuber, cotyledon, and petiole tissues were cultured on MS medium supplemented with different concentrations and combinations of auxins and cytokinins. Shoots were not induced from calli on cotyledon and petiole explants cultured on MS medium containing various concentrations of 2,4-D or NAA. However, multiple shoots were formed directly from tuber explants cultured on the medium containing 0.5 and 1.0 mg/L 2,4-D or NAA. In MS medium with cytokinin alone, TDZ was more effective in shoot formation than BA or kinetin in all explants. The combinations of NAA and BA was found to be most effective in shoot formation from tuber, cotyledon and petiole explants. Especially, shoots were formed from all the tuber explants on the medium containing 0.5 mg/L of NAA and BA. Hormonal effects on root formation were examined by subculturing single shoots on MS medium containing NAA or IBA. The medium with 0.5 mg/L IBA was most effective in root induction and subsequent plantlet regeneration.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.3
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• pp.198-204
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• 2003

A basic experiment was performed to control tile plant growth using acoustic emission technique considering the environmental conditions for plant. At a dry soil condition, the signals due to the cavitation from xylem of angiosperm and gymnosperm were mainly detected. The strong signal from xylem and the weak signal from plasmodesmata and casparian strip were detected at the same time after distilled water was provided. Two signals after providing tile acid and distilled water were contrary to each other. The wind, number of leaf, music, temperature and humidity affected the acoustic emission count from plants but the frequency ranges of the detected signals were the same.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.185-191
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• 2014

Corythucha marmorata (Uhler) belonging to the family Tingidae (Hemiptera) has been reported in Korea. In 2013, surveys were conducted to study its morphological characteristics, geographical distribution, and host plants. The adult is brown white and 2.77-3.28 mm in length, and the mature nymph is yellowish brown. Heavily infested trees appear yellowish white because they are fed on by the nymphs on the under surface of host plants. C. marmorata were found between early June and late October, and their numbers peaked in early July to late August. In 2013, the occurrence of C. marmorata was confirmed in 27 cities and counties nationwide, and 8 families and 24 species of host plants were identified. C. marmorata feeds on the following major host plants: Conyza canadensis, Aster pilosus, Helianthus annuus, Artemisia princeps, Rudbeckia bicolor, and Solanum melongena.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.77-81
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• 1995

When cultured on MS medium supplemented with 0.5 mg/L NAA alone or 1.0 mg/L 2,4-D and 0.5 mg/L BA, immature zygotic embryos of Stewartia koreana formed embryogenic calli and somatic embryos. In investigate effect of sucrose concentration on somatic embryo development, embryogenic calli were transferred to MS basal medium containing 1.5,3, 6 or 9% sucrose. The greatest frequency of somatic embryos was obtained on medium containing 6% sucrose. However addition of 1.5 or 9% sucrose to medium inhibited somatic embryo germination and development into normal plantlet After 5 weeks of hardening culture on medium containing 6% sucrose, somatic embryos were transferred to half strangth MS medium supplemented with 0.1% charcol, wherein these embryo developed into the normal plantlets.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.9-14
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• 1998

Two types of somatic embryos were directly induced from the immature zygotic embryos of the wild prunus yedoensis in Mt. Halla after 16 weeks of culture on MS medium supplemented with 0.1mg/L $GA_3$ and 0.1mg/L BAPor 0.5mg/L $GA_3$ and 0.1mg/L BAP. One was normal single embryo with a single basal part. Normal somatic embryos germinated successfully on 1/2 MS medium. However, abnormal nulticotyledonary somatic embryos, formed shoots only on hormone free MS medium and about 80% of shoots rooted on MS medium with 0.5mg/L IBA. The mximum frequency (62.5%) of normal somatic embryos was directly obtained from the zygotic embryo 30 days after full blooming but it was decreased with further maturation.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.641-647
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• 2015

This study was conducted to select native ground cover plants for sod culture in an organic apple orchard by estimating the effect of three native ground cover plants, Glechoma hederacea, Thymus magnus, and Ixeris stolonifera, on the soil coverage, time-periodic weed occurrence, fruit characteristics, and soil chemical properties. The plant height of G. hederace, T. magnus and I. stolonifera were 15.0 ㎝, 13.4 ㎝ and 7.2 ㎝, respectively. The dry weight of G. hederace, T. magnus and I. stolonifera were 463 ㎏/10a, 247 ㎏/10a, and 255 ㎏/10a, respectively. The plant height and dry weight of G. hederacea were higher than in the other species. T. magnus and I. stolonifera having relatively lower soil cover rate during their life cycle produced a lot of weeds in the orchard as compared with the control. In contrast, G. hederacea showed 100 percentage of ground cover in the first year, and maintained high percentage of ground cover in the growing season of ‘Tsugaru’ apple for another 2 years. When the soil was covered with G. hederacea in the orchard for 3 years, the amount of weed was only 114 ㎏/10a and number of weeding was also reduced about 33% compared with control as well as the other species. There were no differences in the tree growth and fruit characteristics between the native ground cover plants and the control; however, positive effects of native ground cover plants on soil chemical properties were found. In G. hederacea, available P₂O₄content in soils remarkably increased and was a significant difference among native species. In addition, cation (Ca, Mg and K) content in soils increased by 39% in Ca, 6% in Mg, and 11% in K at G. hederacea compared with control. These results suggest that G. hederacea could be advantageous in terms of reducing the amount of herbicide applied and the labor required for weed control, and controlling soil chemical properties; therefore, it is a good candidate for sod culture in an organic apple orchard.