• Journal of Aquaculture
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• v.7 no.4
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• pp.225-237
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• 1994

Survival and growth rates of flounder larvae fed rotifers and Artemia nauplii enriched by various bio-enrichment techniques were investigated. Enriched materials used in the study were $12\omega-yeast$, 2 commercial emulsified oil and microparticulated products. $\omega-yeast$ were added with one kinds of oils (cuttlefish liver oil, sardine oil, Alaska pollock liver oil, linseed oil) at the level of $5\%,\;15\%\;and\;25\%$. The results are as follows: 1. The growth rate of rotifers cultured with $\omega-yeast$ added $15\%$ cuttlefish liver oil was the best among 12 kinds of $\omega-yeast$ and this performance was almost the same with that of rotifers fed on Chlorella. 2. Survival and growth rates of flounder larvae fed on rotifers and Artemia nauplii enriched with $\omega-yeast$ and the other commercial products were higher than that those of larvae cultured with only Chlorella and non-enriched Artemia. The optimum contents of the cuttlefish liver oil in $\omega-yeast$ for rotifers and Artemia enrichment were $15\%\;and\;25\%$, respectively. 3. Optimum enrichment time and supply amount of $\omega-yeast$ for Artemia nauplii were 6 hr., 1.5 g/g cyst, respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.2
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• pp.24-34
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• 2000

The project for rehabilitation and revegetation of the abandoned coal-mine lands is a very important national environmental restoration project in the view point of rehabilitation and revegetation of denuded forest-lands caused by coal mining as well as restoration of disturbed natural environment and control of the variable pollutions. In Korea, because a large number of coal mines had been developed in order to fill up abundantly consumption of coal as a major energy source in the developing period, a lot of denuded forest-lands caused by coal mining had distributed in the whole country. And, due to the absence of effective rehabilitation and revegetation works on the denuded forestlands caused by coal-mining, most of them had been remained with being damaged. In 1990, area of the abandoned coal-mine lands, requiring the rehabilitation and revegetation works, was about 1,437.1 ha. For the past ten years ('90~'99), about 1,081.8 ha out of them had been rehabilitated and revegetated, and the rehabilitation planning area was about 33.0 ha in 2000. So, remaining area out of abandoned coal-mine lands will be about 322.3 ha after 2000. In principle, after abandoning coal-mine, mine owners must carry out the rehabilitation and revegetation works on the abandoned mine lands by themselves. But, most of mine owners were in financial difficulty after abandoning coal-mine, so that principle couldn't have obtained the desired effects. To solve this problem, from 1995, Coal Industry Promotion Board (CIPB) have carried out the rehabilitation and revegetation works on the abandoned coal-mine lands at government budgets, and they have obtained good results in the construction area. However, due to application of the "conventional erosion control measures and techniques" to the rehabilitation and revegetation measures on the abandoned coal-mine lands, the results and effects of the works excuted have not been successful. Therefore, unique measures and techniques for rehabilitation and revegetation of the abandoned coal-mine lands will have to be developed, especially including development of new techniques on the soil-dressing and soil-covering, seed spray and hydro-seeding measures with seed-fertilizer-soil materials as the mechanized measures, and using of new materials for the tree planting and seedling measures.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.77-83
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• 2014

To improve the breeding efficiency of oriental pear, the inheritance of major fruit traits were analyzed using 4,035 seedlings of 15 cross combinations combined with 13 cultivars. Yearly variation of parental cultivars, broad-sense heritability of the traits, and frequency of seedlings with commercially acceptable characteristics by the mid-parent values were studied. Despite the heritabilities of traits related with pear the fruit texture were different depending on cross combination, the average narrow-sense heritability ($h^2$) for firmness, flesh hardness, flesh density and grit were over 0.6, a relatively high value. However fruit firmness showed different heritability among the cross combination and its value of cross combination between 'Niitaka' and 'Choju' was very low as 0.11. Positive correlation was not observed on fresh hardness, fresh density and grit but observed on firmness between mid-parent value and average value of offspring. Regression of offspring on firmness, fresh hardness, fresh density and grit between mid-parent value and average value of offspring were 0.778, 0.343, -0.273, 0.313, respectively. Frequency distributions of fruit texture in 15 cross combinations of pear seedling was influenced by parental characteristics. When fruit firmness was estimated as low, low ${\times}$ high and high ${\times}$ high values in parental fruits, firmness in their offspring exhibited low, medium and high, respectively. In addition, when parental grit by sensory evaluation were light ${\times}$ light and light-medium ${\times}$ medium-heavy, most of offsprings showed light and medium grit, respectively.

• Korean journal of applied entomology
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• v.15 no.1 s.26
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• pp.1-6
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• 1976

his study was conducted to investigate selective toxicity of several organophosphorous and carbamic insecticides against the small brown planthopper (Laodelphax striatellus), the white-backed planthopper (Sogatella furcifera), the brown planthopper (Nilaparvata lugensEugens), and the green rice leafhopper (Nephotetix cincticeps). The test insecticides were the organophosphoric insecticides, Diazinon$(34\%\; Ec.,\; 3\%\; G.),$ $MEP(Sumithion 50\%\; Ec.)$, and PAP(Elsan\; 47.5\%\; Ec.)$ and the carbamic insecticides. MPMC $(Meobal\; 50\%\;WP.)$, $BPMC(Bassa\; 50\%\; Ec.)$, and carbofuran $(Curaterr; 3\%\; G.)$. Toxicitiy for emulsion concentrates and wettable powders were evaluated by dipping method of rice seedlings in the laboratory and that for granulated insecticides evaluated by submerged application with potted plants in the greenhouse. In the test of contact toxicity by seedling dips, Diazinon MEP and PAP showed significantly low toxicity to the brown planthopper and MEP to the green rice leafhopper. In the test of submerged application, Carbofuran showed almost equal toxicity to the four species of the hoppers, but Diazinon was greatly less toxic to the brown planthopper. In general. the organophosphorous insecticides tested seemed to be selective in toxicity to the species of the hoppers, while the carbamic insecticides being less selective. The carbamic insecticides such as MPMC, BPMC and Carbofuran were almost equal in toxicity to the four species of the hoppers tested.

• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.47-53
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• 1977

Bacterial diseases of soybean has been recognized as a limiting factor of soybean production in Korea as it was estimated to cause around 10 percent of yield losses annually. The purpose of the study is to obtain information on the diseases through proving the kinds of pathogens and epidemiology, The wire brush method and multineedle appeared to be the best way of inoculation under all circumstances. Wire brush method, especially, was effective in shortening the incubation period and manifesting the lesion development by introducing more inoculum per unit of area. In case of spray inoculation it was necessary to apply a small amount(1 : 1,000) of wetting agent, twin-20, otherwise it was unabled to produce the diseases under field conditions. Two kinds of bacterial diseases caused by Pseudomonas glycinea and Xanthomonas phaseoli var. sljense were found from surveyed areas in Kore. Wild fire disease on soybean caused by Pseudomonas tabaci had not detectable during the experiment although there were several reports on the disease from other countries. when the pathogens were introduced into sterile soil, bacterial leaf blight pathogen could exsisted until 30 days while bacterial pustule pathogen survived only 4 days under the natural conditions of later June. Both bacteria, however, could produce the disease after more than 10 months period of storage in refrigerator when they were exsisted in infected plant tissues. In warehouse, non-temperature controlled, the bacteria lose their infectability within 6 months period from October to April even though they exsisted in infected tissues. Surface infested seeds with the pathogens could not produced the diseases on seedling stages of soybean plants when the seeds were planted in sterile soil after inoculation by dipping the seeds into bacterial suspensions, although germination was depressed by the pathogens when the seeds were planted on agar media.

• Journal of Life Science
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• v.30 no.3
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• pp.291-297
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• 2020

This study was conducted to develop microsatellite markers in Seriola quinqueradiata using next-generation sequencing. A total of 28,873,374 reads were generated on an Illumina Hiseq2500 system, yielding 7,247,216,874 bp sequences. The de novo assembly resulted in 466,359 contigs. A total of 132 contigs (0.43%), including 60 microsatellite loci, were derived from 30,729 contigs longer than 518 bp. A total of 60 primer sets were designed from the 132 microsatellite loci. A total of 15 polymorphic nuclear microsatellite loci were chosen to evaluate population genetic parameters in the parents and offspring. The mean number of effective alleles was 18.5, ranging from 11 to 30. The observed heterozygosity (H_O) and expected heterozygosity (H_E) ranged between 0.431 and 0.972 with an average of 0.812 and from 0.782 to 0.949 with an average of 0.896, respectively. No significant linkage disequilibrium was observed after Bonferroni revision in any loci. The results show that the 15 polymorphic nuclear microsatellite markers can be used to study the population and conservation genetics of S. quinqueradiata in Korea. To ensure the success of artificial seedling production technology, genetic variations between the parent and offspring populations should be monitored, and inbreeding should be controlled.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.495-501
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• 1995

Betula pendula and B. platyphylla var. japonica seedlings and/or grafts growing inside and outside of a plastic-greenhouse were treated with growth regulators to induce flowering at early stages of seedling and graft developments. The seedlings began to develop female catkins visibly in eight to nine months after seeding and in five months after the first treatment of growth regulators. Thirty three percents of the seedlings grown under controlled environment in the plastic-greenhouse with sufficient nutrient supply developed female catkins both in control plants and in the plants treated with IAA, $GA_3$ and kinetin, while none on the control plants grown in the field showed any sign of the development of floral organs. Sixty seven percents of the seedlings treated with ABA and SADH grown in the Plastic-greenhouse developed female catkins. All the seedlings treated with 6.24 mM of SADH developed female catkins. SADH treatment to 2-5 year old seedlings and grafts of birch had a tendency of positive effect on inducing and increasing the flowering of the two birch species.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.489-494
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• 1995

Seedlings and grafts of Betula pendula and Betula platyphylla var. japonica were grown under partially controlled environments in a greenhouse and in a plastic-greenhouse installed inside a laboratory. Plant growth conditions such as photoperiod, temperature, nutrient supply were partially controlled to enhance the vegetative and reproductive growth of the birch seedlings and grafts. By the treatments twenty and seventy one percents of the seedlings, respectively, for the Betula pendula and Betula platyphylla var. japonica developed visible floral organs between 250 to 508 days after seeding. By the same treatments eighty and fifty three percents of the grafts, respectively, for Betula pendula and Betula platyphylla var. japonica developed visible male catkins between 51 to 497 days and female catkins between 365 to 396 days after grafting. Breeding cycle of birch species can be reduced to a great extent by the induction of precocious flowering at early stages of seedling and graft development.

• Journal of Life Science
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• v.24 no.2
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• pp.196-208
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• 2014

During the life cycle of plants, water deficit leads to an adverse effect on its growth and development. To increase the productivity of crops, overcoming such drought stress is one of the most important issues in the field of plant study. Among plant hormones, the phytohormone, abscisic acid (ABA) plays a crucial role in eliciting resistance to drought stress as well as in multiple developmental processes, such as seed germination, stomatal closure, and seedling growth. Therefore, further understanding of the ABA-mediated signal transduction pathway in plants is an effective strategy to generate drought-tolerant plants. Posttranslational modification, such as phosphorylation and ubiquitination, is an efficient mechanism for plants to acquire quick adaptation against environmental stress conditions since this process directly affects pre-existing signaling components by modulating protein activity and stability. Here, recent reports on ABA signaling are reviewed, especially focusing on ABA transport, perception, signaling, and posttranslational modification in ABA-mediated cellular responses. Also, we present future prospects on how the control of such a mechanism can be applied to generate useful agricultural crops.

• Research in Plant Disease
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• v.16 no.3
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• pp.279-284
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• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.