• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.10-10
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• 1999

• The Plant Pathology Journal
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• v.17 no.6
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• pp.365.2-365
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• 2001

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.499-507
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• 2021

Background and objective: This study was carried out to develop an effective technique for raising seedlings of Veronica pyrethrina Nakai, a native plant species in the Korean Peninsula, in plug trays. Methods: To investigate the optimum plug cell size and sowing media, we sowed seed in to plug trays with 34, 21, and 10 mL cells and filled with a commercial horticultural substrate and mixtures of peatmoss and perlite in 1:1, 3:1, and 4:1 ratios. Fertilization levels were set at 0, 500, 1000 and 2000 mg·L^-1. Results: Plug cell size did not significantly influence the seedling growth of V. pyrethrina. By substrate type, the growth rate was highest in the horticultural substrate, followed by 4:1, 3:1, and 1:1. Growth by fertilization level was higher in all fertilized treatment groups than in the control group, and there was no difference among 500, 1000, and 2000 mg·L^-1. Conclusion: The results of this study proved that it is most suitable for raising seedlings of V. pyrethrina to sow the seeds in a 10 mL cell plug tray filled with horticultural substrates, and apply fertilizers with less than 500 mg·L^-1 concentration.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.181-188
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• 2020

This study was conducted to identify the optimal conditions for seedling growth in Veronica rotunda var. subintegra (Nakai) T.Yamaz. which a endemic plant and can be development as ornamental plants. We sowed V. rotunda var. subintegra (Nakai) T.Yamaz. seeds, and exposed the seedling was different treatment conditions. We varied soil type and fertilizer concentration, shading ratio, additional fertilizer concentration, pretreatment light exposure and collection time of seeds. We found that seedling growth was good in horticultural substrate (with no additional fertilizer), but mixed soils supplemented with fertilizer inhibited growth, regardless of the fertilizer concentration. In the 55% shading treatment, seedling growth was greater than in the non-shading treatment. High concentration addition of fertilizer (Hyponex) promoted plant growth, in terms of both plant length and fresh weight. Exposure of seeds to a red light-source prior to germination had a greater effect on seedling growth than exposure to other light sources. Seedlings exhibited better growth when grown from seed collected in 2018, rather than 2017.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.407-411
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• 2008

This study was conducted to estimate the economic injury level (EIL) and economic threshold (ET) of the green peach aphid, Myzus persicae, on Chinese cabbage (Brassica campestris var). The changes of biomass of Chinese cabbage and M. persicae density were investigated after introduction of M. persicae at different density (0, 2, 5, 10, 15, and 20 per plant; inoculated at 10d after planting). The densities of M. persicae largely increased from the above initial densities to 0, 92.3, 177.4, 406.9, 440.4, and 471.3 aphids per plant at 18d after the initial inoculation, respectively. The biomass of Chinese cabbage significantly decreased with increasing the initial inoculated density of M. persicae: 602.0, 264.2, 262.0, 109.3, 151.0, and 67.3 g in above plots with different initial densities, respectively. The relationship between cumulative aphid days (CAD) and yield loss (%) of Chinese cabbage was well described by a nonlinear logistic equation. Using the estimated equation, EIL of M. persicae on Chinese cabbage was estimated 25 CAD per plant based on the yield loss 13%, which take into account of an empirical gain threshold 5% and marketable rate 92% of spring Chinese cabbage. Also, ET was calculated at 80% of EIL: 20 aphids per plant. Until a more elaborate EIL-model is developed, the present result may be useful for M. persicae management at early growth stage of Chinese cabbage.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.335-345
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• 2020

Tomato grey mould has been one of the destructive fungal diseases during tomato production. Ten mM of menadione sodium bisulfite (MSB) was applied to tomato plants for eco-friendly control of the grey mould. MSB-reduced tomato grey mould in the 3rd true leaves was prolonged at least 7 days prior to the fungal inoculation of two inoculum densities (2 × 10⁴ and 2 × 10⁵ conidia/ml) of Botrytis cinerea. Protection efficacy was significantly higher in the leaves inoculated with the lower disease pressure of conidial suspension compared to the higher one. MSB-pretreatment was not effective to arrest oxalic acid-triggered necrosis on tomato leaves. Plant cell death and hydrogen peroxide accumulation were restricted in necrotic lesions of the B. cinereainoculated leaves by the MSB-pretreatment. Decreased conidia number and germ-tube elongation of B. cinerea were found at 10 h, and mycelial growth was also impeded at 24 h on the MSB-pretreated leaves. MSB-mediated disease suppressions were found in cotyledons and different positions (1st to 5th) of true leaves inoculated with the lower conidial suspension, but only 1st to 3rd true leaves showed decreases in lesion sizes by the higher inoculum density. Increasing MSB-pretreatment times more efficiently decreased the lesion size by the higher disease pressure. MSB led to inducible expressions of defence-related genes SlPR1a, SlPR1b, SlPIN2, SlACO1, SlChi3, and SlChi9 in tomato leaves prior to B. cinerea infection. These results suggest that MSB pretreatment can be a promising alternative to chemical fungicides for environment-friendly management of tomato grey mould.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.805-805
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• 2015

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.209-213
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• 2008

This study was conducted to regenerate shoots from internode sections(about 1mm in thickness) of Ardicia pusilla de Candolle. Internode sections were cultured on MS medium supplemented with TDZ or both TDZ and IBA. At one month after culture, primodium, which looks like protocorm like body(PLB) of orchid, appeared around swollen internodes. And then it grew and changed into the shape similar to granule of orange at two or three months after culture. At four to five months after culture, explants covered with them became a cluster, and then multiple shoots were regenerated from them. Primodia formation was the best when internode was cultured on MS medium supplemented with 0.25 $mg{\cdot}L^{-1}$ thidiazuron(TDZ) and 0.5 $mg{\cdot}L^{-1}$ indole-3-butyric acid(IBA). That internodes were cultured on MS medium supplemented with either higher concentration of TDZ than that of IBA, or equal concentration of TDZ and IBA, or TDZ only was little effective for primodia formation.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.297-301
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• 2004

A Tomato spotted wilt virus (TSWV-KP) was isolated from Paprika (Capsicum annuum var. grossum) showing necrosis spot on the leaves and malformation of the fruit in Yesan, Korea. The virus infected Chenopodium amaranticolor, C. quinoa, Petunia hybrida, Nicotiana glutunosa, Gomphrena globosa, and Physalis floridana. Ten plants including tomato were observed to have systemic TWSV-KP infection. The virus produced necrosis or necrotic ring spots on the inoculated leaves and mosaic, vein necrosis or death on the upper leaves of Datura stramonium, N. clevarandii, N. rustica, and N.tabacum cvs. Thin sections of the infected leaf tissue contained spherical to oval particles, a characteristic of a Tospovirus. The virion contained three molecules of genomic RNAs, which were approximately 9.0, 4.9 and 3.0 kb. The nucleocapsid (N) protein of the purified virion migrated as a single band with molecular weight of about 29 kDa in SDS-PAGE. The N gene of TSWV-KP showed 96.5-97.2% and 97.7-98.5% identities to the three different TSWV isolates of Genbank Database at the nucleotide and amino acid, respectively.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.465-470
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• 2013

In January 2012, spreading type petunia cv. Wave Pink plants showing an abnormal growth habit of sprouting unusual multiple plantlets from the lateral buds were collected from a greenhouse in Gwacheon, Gyeonggi Province, Korea. The presence of phytoplasma was investigated using PCR with the primer pairs P1/P6, and R16F1/R1 for nested-PCR. In the nested PCR, 1,096 bp PCR products were obtained, and through sequencing 12 Pet-Stol isolates were identified. Comparison of the nucleotide sequences of 16S rRNA gene of the 12 Pet-Stol isolates with other phytoplasmas belonging to aster yellows or Stolbur showed that Pet-Stol isolates were members of Stolbur. The presence of phytoplasma in petunia was also confirmed by microscopic observation of the pathogens. In this study, Stolbur phytoplasma was identified from spreading type petunia cultivars by sequence analysis of 16S rRNA gene of phytoplasma and microscopic observation of phytoplasma bodies. This is the first report of Stolbur phytoplasma in commercial Petunia hybrida cultivars.