• Research in Plant Disease
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• v.24 no.4
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• pp.328-331
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• 2018

A severe disease with leaf spots and necrotic symptoms was observed in cucumber (Cucumis sativus L.) seedlings in April 2018 at a nursery in Kimjae, Korea (35o 47'09.8"N 127o 2'24.3"E). The infected plants initially showed spots on water-soaked cotyledons which, at later stages, enlarged and spread to the leaves, which the lesions becoming dry and chlorotic. The symptomatic samples were collected from cucumber and the isolates were cultured on LB agar. The representative bacterial strain selected for identification showed fluorescent on King's medium B, was potato rot-positive, levan and arginine dihydrolase-negative, oxidase-negative and tobacco hypersensitivity-positive in LOPAT group 2 as determined by LOPAT tests. A pathogenicity test was carried out on a 3-week-old cucumber. After 3 days of inoculation, leaf spots and necrotic symptoms appeared on the cucumber, similar to the originally infected plants. The infecting bacterial strain was identified as Pseudomonas viridiflava, by 16S rDNA sequence analysis. This is the first report of leaf spot diseases on cucumber caused by P. viridiflava.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.04a
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• pp.13-13
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• 1999

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.41-41
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• 1996

Chilling-sensitive plants are damaged severly by chilling in the light. The activity of photosystem I(PSI) is known to be inhibited by low light-chilling and its iron-sulfur centers are presumed to be its primary target. In this report, the effect of chilling at 4$^{\circ}C$ in the light was investigated in the level of pigment-protein complexes in cucumber leaves compared with pea leaves. (omitted)

• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.246-256
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• 1995

Phenotypic characteristics, pathogenicity and fungicides resistance of fifty one isolates of Botrytis cinerea obtained from various host plants were observed and determined. The relationships between these characteristics were also investigated on the basis of isolation host plants. The isolates of B. cinerea varied in the capacity of sclerotia formation and sporulation. The pathogenicity of 44 isolates from tomato, cucumber, and strawberry was significantly stronger with 3.2 cm in average diameter of necrotic lesions on cucumber leaves than that of seven isolates from other host plants such as orange, gerbera, ginseng, kiwi, grape, pear and from butter with 1.8 cm in average diameter of necrotic lesions. Benomyl resistance of 12 isolates from tomato plants was much higher with the $EC_{50}$, 562 ppm than that of 19 isolates from various host plants. Diethofencarb resistance, however, of 11 isolates from strawberry plants was highest with the $EC_{50}$, 210 ppm among isolates from other host plants. Polygalacturonase activity varied among isolates in the range of 0 to 103 unit and that of isolates from tomato, cucumber and strawberry was slightly lower than that of isolates from other host plants. No significant relationship between pathogenicity and fungicides resistance, polygalacturonase activity was found among 51 isolates of B. cinerea. Isozyme patterns of polygalacturonase produced from two strongly and weakly pathogenic isolates (FC122, KC6) were slightly different depending upon carbon sources during cultivation.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.1-14
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• 1997

This experiment was conducted to find out the compositions of nutrient solution for closed system in substrate culture of cucumber. Cucumber(Cucumis sativus L. cv. Eunsung baekdadagi) plants were grown in the substrates supplied with the nutrient solutions whose strengths were 1/2, 1, and 3/2 of the original concentration developed by National Horticultural Research Station in Japan. By increasing the nutrient concentrations, plant height decreased but leaf length, leaf width, and leaf number showed little differences. A number of marketable fruit and marketable yield were the highest in the concentration of 1 strength. The nutrient compositions of solution developed for closed system in cucumber substrate culture were N 11.4, P 3.3, K 6.0, Ca 4.5, and Mg 3.5 me.$\ell$$^{-1}$ during the vegetative growth period and N 10.4, P 3.3, K 5.0, Ca 4.5, and Mg 3,5 me.$\ell$$^{-1}$ during the reproductive growth period. To examine the suitability of nutrient solution developed in the above experiment, cucumber plants were grown in the substrates supplied with different solutions and concentrations - Yamasaki's nutrient solution(Yamasaki) of 1 S, nutrient solution of Research Station for Greenhouse Vegetable and Floriculture on the Netherlands(PTG) of 1 S, nutrient solution developed in the above experiment(SCU) of 1/2, 1, and 3/2 S. EC and pH in root zone changed little in the all treatments during growing period. As cucumber plants grew, the concentrations of N, P, and K in root zone decreased but Ca concentration increased. Net $CO_2$ assimilation rate of cucumber leaves was high in SCU of 1 and 3/2 S, and Yamasaki of 1 S. Growth of cucumber plants was the lowest in SCU of 1/2 S.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.150.1-150
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• 2003

A single-step multiplex reverse transcription polymerase chain reaction (RT-PCR) assay was developed for the simultaneous detection of five cucurbit-infecting viruses： cucumber mosaic virus (CMV), watermelon mosaic virus 2 (WMV2), zucchini yellow mosaic virus (ZYMV), cucumber green mottle mosaic virus (CGMMV), and kyuri green mottle mosaic virus (KGMMV). The multiplex RT-PCR provides a simple and rapid method for detecting various viruses in cucurbit plants, which will help diagnose many cucurbit plants at a time.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.373.5-374
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• 2001

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.149-155
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• 1995

The coat protein (CP) gene was cloned from RNA genome of the Cucumber Mosaic Virus strain ABI (CMV-ABI) isolated in Korea. The comparisons of the nucleotide sequence of the cloned CP gene and its deduced amino acid sequences with other CP genes revealed that the CMV-ABI belongs to subgroup I (type I), CMV-ABI developed the typical mosaic symptom in infected plants. Tobacco plants (Samsun and NC82) were transformed by leaf-disc transformation via Agrobacterium, temefaciens LB4404 harboring pVCP, witch CMV-ABI CP gene was inserted into the pBI121, and a number of mature transgenic tobacco plants were developed. Southern and PCR analysis of genomic DNA from the transgenic plants showed that the CP gene was integrated into the genomes of the most of the transgenic plant. Result of the segregation patterns of resistance in T1 seedlings of the plants to kanamycin showed that the transgenic plants containing l,2 and 3 copies of CP gene were50%, 39% and 11% of the total transgenic plants, respectively.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.309-313
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• 2000

To investigate the effects of different UV-B levels on growth and biochemical defense response in plants, cucumber plants were subjected to three levels of biologically effective ultraviolet-B $(UV-B_{BE})$ radiation [daily dose: 0.03 (No), 6.40 (Low) and $11.30\;(High)\;kJ{\cdot}m^{-2}$, $UV-B_{BE}$] in the growth chambers for 3 weeks during the early growth period. Enhanced UV-B radiation drastically decreased both dry weight and leaf area of cucumber. With increasing UV-B intensity, chlorophyll content was decreased, however the level of malondialdehyde was highly increased linearly. Total contents of ascorbic acid and glutathione were tended to increase by UV-B, while the ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were significantly increased with increasing UV-B intensity in cucumber. All the enzyme activities investigated (superoxide dismutase, ascorbate peroxidase, dehydroascorbate reductase, guaiacol peroxidase etc.) in cucumber were increased by the UV-B enhancement. These results suggested that enhanced UV-B irradiation caused photooxidative stress in cucumber plant and resulted in significant reduction in plant growth. Biochemical protection responses might be activated to prevent the leaves from damaging effects of oxidative stress generated by UV-B irradiation.

• Research in Plant Disease
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• v.15 no.3
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• pp.175-182
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• 2009

We investigated the effect of the infection times and infection degrees at transplanting time of Zucchini yellow mosaic virus (ZYMV) on the growth and yield of cucumber plants at the semi-forcing and the retarding culture in 2007. When cucumber was inoculated with ZYMV at transplanting time, 15, 30, 45, 60, and 75 days after transplanting, vine length, internode length, number of leaf of the plants and marketable yield largely decreased as the cucumber infected earlier. The regression models were obtained between the disease incidence levels at 20 days after transplanting as the inoculation degrees and the marketable yield of cucumber: y = $9333.1e^{-0.0317x}$ ($R^2$ = 0.8946) at the semi-forcing culture and y = $14695e^{-0.0303x}$ ($R^2$ = 0.8735) at the retarding culture. And the cucumber yield loss regression models between the symptoms incidence days from the final harvesting time and the rates of yield decrease were expressed as y=1.0851x - 6.7067 ($R^2$ = 0.9567) at the semi-forcing culture andy=1.0439x + 2.1321 ($R^2$ = 0.9674) at the retarding culture.