• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.121-124
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• 2001

Potato (Solanum tuberosum L.) tubers of 10, 20, 30, 40, and 50 g were planted in plug trays with vermiculite-based root medium on 10 August 2000 and grown for 15 days in a glasshouse to determine the effects of mini-tuber size on plug seedling growth and field performance of plug seedlings. For a control, common potato tubers weighing 50 g were also planted. As size of seed tubers planted increased from 10 to 50 g, seedling height decreased from 24.6 to 20.0cm while shoot number per seedling increased from 2.0 to 3.5, main stem diameter from 4.3 to 6.1mm, and fresh weight of root + top from 9.3 to 19.4 g/seedling. At 90 days after transplanting plug seedlings, the total number of tubers per plant increased from 3.62 to 4.72, average tuber weight from 62.9 to 72.8g, and total tuber yield 20.5 to 23.6 t/ha with increase in seed tuber size. Plug seedlings raised from 50g tubers produced 22% more tubers per plant and had 21 % higher＞80g tuber yield than the directly planted potatoes.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.222-227
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• 1998

The activities of enzymes of carbohydrate metabolism have been determinated in the host cytosolic and bacteroid fractions of cowpea (Vigna unguiculata) nodules formed with B. japonicum I 16 and in roots of nodulated cowpeas. The host cytosolic fraction of the nodules contained the enzymes of glycolytic pathway and the pentose phosphate pathway, whereas the bacteroids had only limited capacity for carbohydrate metabolism and appeared to be insufficient for the complete glycolytic pathway as well as starch synthesis and degradation. In a time-course study, using plants grown in a glasshouse, the acetylene-reducing activity (ARA) of the nodules increased in parallel with the total N content of plants and protein of the nodules until approximately 8 weeks after planting. Subsequently, the weight and size of the nodules and the weight of the plants continued to increase, but there was a sharp decrease in the ARA and the total N content of the plants.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.690-694
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• 2006

There is limited information on the relationship between defoliation and root and rhizome development of kura clover (Trifolium ambiguum M. Bieb.). To determine the effects of defoliation severity on root and rhizome growth of young kura clover plant (seedling about 8 wk old), this research was conducted in 2002 (Experiment 1) and 2003 (Experiment 2) in a glasshouse at the University of Wisconsin-Madison. Four kura clover entries were used in this experiment: two were started from seed materials (ARS-2678 and 'Rhizo') and two were clones from mature, field-grown Rhizo kura clover plant. Three defoliation frequencies (2-, 4- and 6-wk intervals) and two defoliation intensities (complete and partial defoliation) were imposed on each of the four kura clover entries. Root, rhizome, and leaf dry matter (DM) generally increased with less frequent defoliation, however, the increase in rhizome DM was not significant between 4- or 6-wk defoliation periods. The root and leaf DM under complete defoliation (CD) were significantly lower than under partial defoliation (PD). In Exp. 1, rhizome DM was not significantly different between CD and PD; it was significantly lower under CD in Exp. 2. ARS-2678 showed excellent root development characteristics, however, its rhizome DM was significantly lower than Rhizo clones. The rhizome development from Rhizo clones was greater than that from seed materials. If maximum root and rhizome growth are expected from young kura clover plant, the intensity and frequency of defoliation should be minimized or defoliation should be avoided.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.181-187
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• 2008

An entomopathogenic fungus, Paecilomyces fumosoroceus SFP-198 was isolated in Kyungbuk province, Korea and screened out for the control of Trialeurodes vaporariorum nymphs. It showed 72.5% efficacy against second instars of T. vaporariorum nymphs at 6 days after treatment in the laboratory. To select an active ingredient for the mass production and the formulation, SFP-198 culture products were compared based on their insecticidal activities against T. vaporariorum nymphs. Among them, conidia and blastospores showed much higher insecticidal activity than supernatants. Furthermore, SFP-198 conidia were more heat-resistant than blastospores, and also powder form of conidia was more stable than their suspension form. SFP-198 conidia showed high pathogenicity on not only T. vaporariorum but also Tetranychus urticae in the glasshouse. This result suggested that SFP-198 conidia can be used as a multi-targeting biological control agent against sucking agri- cultural pests, such as whiteflies and mites.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.113-118
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• 2004

Somatic embryos were formed from calli obtained from axillary shoots (raised from nodal segments of glasshouse-grown plants under aseptic conditions), internodal segments (from in vitro-raised plants), and root and coty-ledonary leaf segments (from in vitro-raised seedlings) after 8 weeks of initial culture. Embryo formation was the highest (97.33%) from cotyledonary leaf callus on Mura-shige and Skoog's (MS) medium containing kinetin (KN) (3 mg/L). Somatic embryo induction was lesser with different combinations of auxins while it increased to 100% in internodal segment and cotyledonary leaf calli with 6-benzyladenine (BA) (2mg/L) along with 2,3,5-triiodobenzoic acid (TIBA) (2mg/L). The shoots were induced from somatic embryos raised from root, coty-ledonary leaf and internodal segment calli grown on MS medium containing BA in combination with indole-3-acetic acid (IAA). Maximum of 66.67% cultures formed shoots on MS medium containing BA (1mg/L) in combination with IAA (2mg/L). The shoots raised from somatic embryos were rooted on MS medium supplemented with indole-3-butyric acid (IBA) (2mg/L). The plantlets transferred to the field showed 70% survival rate after one year.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.144-148
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• 2009

The transfer of Mn-Superoxide Dismutase (SOD2) gene, complex gene (SA) of CuZnSOD and ascorbate peroxidase (APX), and NDP kinase 2 (NDPK2) gene into Korean 4 cultivars (cvs. Millenium White, Glory Blue, Glory Red, and Glory Purple) and 15 purebred lines of petunia was conducted using Agrobaterium-mediated technique. Two (Wongyo A2-16 and A2-36) of 15 purebred lines and one (cv. Glory Red) of 4 cultivars were effective for the transfer of SOD2 gene. The putative transgenic plants survived on the 2nd selection medium were 124. From PCR analysis, 118 (derived from 4 cultivars and 2 purebred lines) of 124 plants were confirmed to contain marker (npt II ) gene, while 58 of 118 plants did not have target genes. There were no plants with both npt II and SA genes. Twenty seven of 28 SOD2 transgenic plants were re-confirmed as transformants by Sothern analysis. SOD2 and NDPK2 genes were expressed in the transgenic petunias as the ratio of 77.8 to 100.0 % and 23.5%, respectively. T1 seeds were obtained from 36 acclimated transgenic plants (SOD2 34 plus NDPK2) in a glasshouse by self-pollination.

• Research in Plant Disease
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• v.10 no.1
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• pp.25-29
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• 2004

Over 98％ of Dendranthema x grandiflorum plants growing under a glasshouse in Gumi, Korea were infested with Meloidogyne hapla. Dendranthema x grandiflorum cv, 'Ardilo' had fewer eggmass (3.3/g root), followed by cv. 'Euro' (6.5), and cv. 'Monarisa' had the most eggmasses(17). The coefficient correlation between plant growth and nematode reproduction(number of eggmass per plant) indicated that nematode reduced chlorophyll content in leaf (r = -0.418, p = 0.059; r = -0.463, p = 0.040). Number of flowers, number of leaves and stem height to flower were positively correlated with flower weight(p < 0.05).

• The Plant Pathology Journal
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• v.24 no.3
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• pp.279-282
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• 2008

This study describes a phytoplasmal disease occurring in Petunia leaves grown in the glasshouse of the National Horticultural Research Institute, Suwon, Korea. Abnormal growth like flattened stem with flower malformation or phyllody was observed from the plant. The DNA extracted from the diseased leaves was amplified using a universal primer pair of P1/P6 derived from the conserved 16S rRNA gene of Mollicutes giving the expected polymerase chain reaction(PCR) product of 1.5 kb. In the nested PCR assays, the expected DNA fragment of 1.1 kb was amplified with the specific primer pair R16F1/R16R1 that was designed on the basis of aster yellows(AY) phytoplasma 16S rDNA sequences. The 1.1 kb PCR products were cloned and nucleotide sequences were determined, and the sequences of the cloned 168 rRNA gene were deposited in the GenBank database under the accession no. of EU267779. Analysis of the homology percent of the 168 rDNA of PFS-K showed the closest relationship with Hydrangea phyllody phytoplasma(AY265215), Brassica napus phytoplasma(EU123466) and AY phytoplasma CHRY(AY180956). Phytoplasma isolated from the diseased Petunia was designated as Petunia flat stem phytoplasma Korean isolate(PFS-K) in this study. Flattened stem occurring in Petunia was confirmed as infection of AY group of phytoplasma by determination of 16S rRNA gene sequences of phytoplasma and microscopic observation of phytoplasma bodies. This is the first report on the phytoplasmal disease in Petunia in Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.81-87
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• 2017

The total area of domestic reclaimed lands is 54,379 ha, and among these, 30,394 ha can be agriculturally available. To increase an agricultural availability of reclaimed land, controlled horticultural products that can be highly profitable have come to the fore. However, as being characteristically concerning, when original glasshouse is intactly applied in reclaimed land, it is unsafe on account of ground subsidence and, even if ground were reinforced, it has a problem by high cost. So a new greenhouse model would be necessary taking into account not only cost-efficiency but also safety with relatively light-weight one. Before this, this paper estimated acceptance rate of controlled horticultural complexes in reclaimed land and new greenhouse model for 414 farmers. The annual rental fee is 129,712,500 won/ha, considering the interest rate (2.5 %) of the investment, the depreciation cost of the facilities (straight line depreciation method, 20 years of service life estimated), and government subsidy rate (50 %) which resulted in a sufficient number of intended tenants with the acceptance rate of 0.33. The results of this paper may contribute to the government's policies for reclaimed land.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.107-113
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• 2003

The effect of sodium sulphate on shoot induction and multiple shoot formation from nodal explants of Vitex negundo L. was tested on Murashige and Skoog's (MS) medium fortified with different auxins, cytokinins and sucrose. Highest percentage $(97.78\%)$ of explants for shoot induction and multiple shoot (20.68/explant) production were observed in the combination treatment of $N^6-Benzyl$ adenine (BA) $(17.80\;{\mu}M/L)$, ${\alpha}-Naphthalene$ acetic acid (NAA) $(2.15\;{\mu}M/L)$ and $5\%$ sucrose supplemented with 100 mg/L sodium sulphate. In vitro raised shoots were rooted on the half-strength MS medium fortified with different concentrations of NAA, Indole-3-acetic acid (IAA), and Indole-3-butyric acid (IBA) alone and in combinations. Among the treatments, $4.90\;{\mu}M/L$ of IBA was found most effective $(95.56\%)$ in inducing roots. The rooted plantlets were shifted to glasshouse for acclimatization and later transferred to the field with cent percent survival. Furthermore, in vitro flowering was observed in the shoots cultured on MS medium supplemented with BA $(8.90\;{mu}M/L)$ and NAA $(1.61\;{\mu}M/L)$.