• 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.

• Research in Plant Disease
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• v.23 no.3
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• pp.228-233
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• 2017

Six commercial rootstock varieties were tested for resistance to bacterial wilt (Ralstonia solanacearum) by dipping the roots of seedlings in the bacterial suspension at seedling stage. 'Shincheonggang' and 'B-Blocking' ranked top and second in resistance to bacterial wilt, respectively. For disease index of the grafted plants, 'Dotaerang' grafted onto 'Shincheonggang' was the least, followed by 'Ultra', 'Fighting', 'B-Blocking', 'Special', and 'Connection' grafts. Thus, disease development on the grafted plants was correlated with resistance of rootstocks. The effect of rootstocks on horticultural characteristics including days to flower of scion was minimum or negligible. In correlation between horticultural characteristics of rootstocks and scions grafted thereon, statistically significant negative correlation was observed in days to flower and fruit height but no significant correlation was observed in yield per plant, fruit diameter and soluble solid content in the fruits. Thus, selection of resistant rootstock varieties that support the growth and yield of scion well is necessary for effective control of the disease and yield increase.

• The Korean Journal of Malacology
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• v.26 no.4
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• pp.303-310
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• 2010

Rearing condition and species of microalgae on growth and survival of the sunray surf clam, Mactra chinensis larvae were investigated for artificial seedling production. The larvae of M. chinensis on higher temperature showed high growth and low survival and was grown over $230{\mu}m$ in shell length 14 days after hatching, but low growth as $151.1{\mu}m$ at $18^{\circ}C$. The larvae of M. chinensis on salinity showed highest daily growth and survival as $11.3{\mu}m$ and 65.8% at 30 psu, respectively. The optimum of water temperature and salinity for the larval rearing were $23^{\circ}C$ and 30-35 psu over 25 psu at least. The density of larval rearing was below 10 per 1 ml in rearing seawater for elevating the development rate from D-shaped to settled (metamorphosing) stage. The larvae fed the mixed diet of Isochrysis galbana, Pavlova lutheri, Isochrysis sp. (green), Chlorella ellipsoidea showed highest growth and survival. The larvae fed the single diet of I. galbana, Isochrysis sp. (green) showed high growth and survival. But the larvae fed the single diet of P. lutheri and C. ellipsoidea showed low growth and survival. The optimum diet of larvae of M. chinensis was over two species of microalgae included I. galbana, Isochrysis sp. (green) for elevating the high growth and survival.

• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.108-114
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• 2007

This study was conducted to clarify the effects of the different mixing ratios of substrate mixtures based on peat moss and the concentration of nutrient solution on the growth of tomato (Lycopersicon esculentum Mill.) seedlings. Substrates such as peat moss, rice hull, carbonized rice hull, decomposed sawdust, perlite and granular rock wool were mixed and used. The concentration of nutrient solution were adjusted to EC $0.5{\sim}1.5mS/cm$. The volumetric moisture contents became higher as peat moss mixed were much more. Total porosities in all substrate mixtures were over 80%, and pH in substrate mixtures became lower as the volume of peat moss mixed higher. Mixing ratios of substrates suitable for the production of tomato seedlings with the higher quality were peat moss:rice hull:carbonized rice hull:decomposed sawdust:perlite=25:10:25:20:20(v/v). The plant growth was not significant among the different substrate mixtures. However, plant growth such as plant height, leaf area, and total dry weight became significantly increased as EC increasing.

• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.45-50
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• 2005

Virus-free stocks was produced by the combination of the heat treatment of virus infected plant and shoot-tip grafting (STS). To produce virus-free stocks, the plants infected with citrus viruses were used for virus-free stock production using the modified method of STG in thermotherapy at $40^{\circ}C$ for 16 hours in the light, and at $30^{\circ}C$ for 8 hours of darkness for 4 weeks. Trifoliate orange (P. trifoliata) were used as rootstock seedling for STG. Percentages of virus-free stocks against citrus tristeza virus (CTV), satsuma dwarf virus (SDV) and citrus tatter leaf virus (CTLV) were $75.7\%,\;100.0,\%\;82.6\%$ respectively. Shoot tip size for successful STG were as small as possible. Less than $0.3\;\cal{mm}$ of shoot tips gave the hight efficiency of virus free plants but survival rates were low. And, survival rate after shoot-tip culture was analyzed and the rates were dependant on the cultivars; Yuzu cultivar showed the hight survival rate ($74.6\%$) and early satsuma mandarin (Iwasagi) was $13.3\%$ as the lowest cultivar. But citrus trees were not succeed to grown, turned brown, and died.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.293-300
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• 2005

The possible role of nitric oxide (NO)-induced cell division was investigated to explain the physiologycal effects of a NO donor, sodium nitroprusside (SNP) on the growth of primary leaves in chinese cabbage seedling plants. Exogenous treatment of SNP to chinese cabbage plants for 8 days at different concentrations (0, 200, 500 and 1000 ${\mu}M$) affected the leaf growth in a concentration-dependent manner, showing a maximum growth at $200\;{\mu}M$. In accordance with leaf growth responses, the chlorophyll and soluble protein contents increased strongly to 142% and 134% of control at $200\;{\mu}M$ SNP, respectively. However, a very little decrease in chlorophyll and a 13%> decrease in protein were observed at $1000\;{\mu}M$ SNP. In addition, the content of DNA and RNA also increased maximumly to 142% and 139% of the control at $200\;{\mu}M$ SNP, respectively, whereas they decreased to 80% and 84% of the control at $1000\;{\mu}M$ SNP. With respect to the development of enzymes related to cell wall synthesis, $200\;{\mu}M$ SNP led to the maximum activities in both phenylalanine ammonia-lyase (212% of the control) and guaiacol peroxidase (134% of the control). However, the activities of both enzymes were not modified significantly at $1000\;{\mu}M$ SNP. In conclusion, these results suggest that the enhancement of leaf growth in chinese cabbage plants by SNP at the effective concentration was probably due to the NO ability in the induction of cell division.