• The Plant Pathology Journal
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• v.35 no.4
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• pp.341-350
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• 2019

Streptomyces padanus PMS-702 strain produces a polyene macrolide antibiotic fungichromin and displays antagonistic activities against many phytopathogenic fungi. In the present study, experimental formulations were assessed to improve the production of fungichromin, the efficacy of PMS-702 on the suppression of sporangial germination, and the reduction of cucumber downy mildew caused by Pseudoperonospora cubensis. PMS-702 strain cultured in a soybean meal-glucose (SMG) medium led to low levels of fungichromin accumulation and sporangial germination suppression. Increasing medium compositions and adding plant oils (noticeably coconut oil) in SMG significantly increased fungichromin production from 68 to $1,999.6{\mu}g/ml$. Microscopic examination reveals that the resultant suspensions significantly reduced sporangial germination and caused cytoplasmic aggregation. Greenhouse trials reveal that the application of PMS-702 cultural suspensions reduced downy mildew severity considerably. The addition of Tween 80 into the synthetic medium while culturing PMS-702 further increased the suppressive efficacy of downy mildew severity, particularly when applied at 24 h before inoculation or co-applied with inoculum. Fungichromin at $50{\mu}g/ml$ induced phytotoxicity showing minor necrosis surrounded with light yellowish halos on cucumber leaves. The concentration that leads to 90% inhibition (IC90) of sporangial germination was estimated to be around $10{\mu}g/ml$. The results provide a strong possibility of using the S. padanus PMS-702 strain as a biocontrol agent to control other plant pathogens.

• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.101-107
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• 2007

This experiment was carried out to develop the substrate mixtures for the production of high quality plug seedlings of cucumber. Peatmoss based substrates, rice hull, carbonized rice hull, decomposed sawdust, perlite and granular rockwool were mixed by five different mixing ratioes (M1, M2, M3, M4 and M5). The cultivars used were cucumber (Cucumis sativus L. cv. Janghyung heukjinju) plants. The higher the content of peatmoss added, the higher the plant growth in terms of plant height, leaf area and total dry weight, which leading to the production of high quality plug seedlings. Seedlings growth of cucumber were greater in M5 mixtures [peatmoss:rice hull:decomposed sawdust=40:40:20(v/v)], M4 mixtures [peatmoss:rice hull:decomposed sawdust:granular rockwool=30:25:20:25(v/v)] and M2 mixtures [peatmoss:rice hull:decomposed sawdust:granular rockwool=20:20:15:25:20(v/v)] The concentrations of nutrient solution (EC) had a great influence on plant height, leaf area, total fresh and dry weight of cucumber seedlings growth. As the concentration of nutrient solution increased from 0.1 to $1.5dS{\cdot}m^{-1}$, the growth and seedling quality of cucumber in plant height, leaf area and dry weight were significantly improved.

• Research in Plant Disease
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• v.20 no.2
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• pp.112-118
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• 2014

A liquid bio-formulation containing chitinolytic bacteria, chitin and their products was assessed for its potential biological control against root-knot nematodes on cucumber. The bio-formulation was prepared by cultures of three chitinolytic bacteria, Chromobacterium sp. strain C-61, Lysobacter engymogenes and Serratia plymuthica in minimal medium supplemented with chitin. Under pot conditions, the bio-formulation showed better growth of cucumber plants, and less root galls and population density of Meloidogyne spp. than control media without the bio-formulation. In a greenhouse, 75-fold diluted bio-formulations were treated instead of water around cucumber plants through hoses for drip irrigation six times at 5-day intervals from the transplanting date. After 30 and 60 days, the treatment provided about 7% and 10% enhancement in the plant height and about 78% and 69% reduction in population density of Meloidogyne spp. in the rhizosphere, respectively. In addition, the experiments showed that the control effects occurred only in the soils contacted with the bio-formulation. Undiluted bio-formulations were drenched three times at 10-day intervals around cucumber plants severely infested with Meloidogyne spp. The treatment showed about 37% plant enhancement without dead plants compared with 37% death in the untreated control, and about 82% nematode reduction. These results suggest that the bio-formulation can be practically used to control the root-knot nematode on cucumber.

• Korean Journal Plant Pathology
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• v.14 no.1
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• pp.46-51
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• 1998

A method for inoculum production of Botryosphaerisa dothidea was developed using cucumber disks and cereal media. Disks of cucumber fruits, and cereal media of barley, wheat, and rice seeds were inoculated with mycelial plugs of B. dothidea and incubated at 27$^{\circ}C$. Pycnidia were produced on the surface of cucumber disks and seeds after 5 days of inoculation. When the inoculated barley seeds were immersed in sterilized distilled water for 5 minutes, abundant conidia of B. dothidea were exuded from mature pycnidia. Conidia were held together by mucilage as they were released from an ostiole. Compared with the conventional method for inoculum preparation using agar media, such as potato-dextrose agar and oatmeal agar, this method could minimize the tedious work required for inoculum preparation within a shorter period of time.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.592-599
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• 2023

A defective RNA3 (D3Yα) of strain Y of cucumber mosaic virus (CMV-Y) was examined on host-specific maintenance, experimental conditions, and a viral factor required for its generation in plants. D3Yα was stably maintained in cucumber but not in tomato plants for 28 days post inoculation (dpi). D3Yα was generated in Nicotiana tabacum or N. benthamiana after prolonged infection in the second and the third passages, but not in plants of N. benthamiana grown at low temperature at 28 dpi or infected with CMV-Y mutant that had the 2b gene deleted. Collectively, we suggest that generation and retention of D3Yα depends on potential host plants and experimental conditions, and that the 2b protein has a role for facilitation of generation of D3Yα.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.20-27
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• 1994

This study was conducted to improve marketing value and productivity of cucumber which was cultivated with primary scaffold stem type (Mannungcheongjang) and lateral stem type (Sayeup). The results are summarized as follows ; 1. Investigation of fruit setting characteristics to improve cucumber training type was resulted that the fruit-thinning was effective 3 nodes in Mannung- cheongjang and 4 nodes in Sayeup, because of defected yield potential and marketing value. 2. In the matter of early growing stage after training and cucumber quality at different treatment, cucumber weight at flowering curved cucumber and growth analysis of Mannungcheongjang were good in order of horizontal>vertical>slant training. And those of Sayeup were good in order of horizontal >slant> vertical training. 3. Aspect of light reception of cucumber plant in the level of plant height and accumulated leaf area index, vertical and horizontal training are better than slant in Mannungcheongjang, and there is order of horizontal >vertical >slant training in Sayeup. 4. Horizontal training in Mannungcheongjang was superior to any other case In view of cucumber number, productivity, and marketing rate. Therefore, this training was suggest ed of best method in cucumber cultivation.

• Plant Breeding and Biotechnology
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• v.5 no.2
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• pp.123-133
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• 2017

AP2/EREBP gene family consists of transcription factor genes with a conserved AP2 DNA-binding domain and is involved in various biological processes. AP2/EREBP gene families were identified through genome-wide searches in five Cucurbitaceae species including cucumber, wild cucumber, melon, watermelon, and bitter gourd, which consisted of more than 100 genes in each of the five species. The gene families were further divided into five groups including four subfamilies (ERF, DREB, AP2 and RAV) and a soloist group. Among the subfamilies, DREB subfamily which is known to be related to abiotic stress response was more analyzed and a total of 25 genes were identified as Cucurbitaceae homologues of Arabidopsis CBF/DREB1 genes which are important for abiotic stress-response and tolerance. In silico expression profiling using RNA-Seq data revealed diverse expression patterns of cucumber AP2/EREBP genes. AP2/EREBP gene families identified in this study will be valuable for understanding the stress response mechanism as well as facilitating molecular breeding in Cucurbitaceae crops.

• Journal of Plant Biotechnology
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• v.7 no.4
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• pp.225-231
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• 2005

Five day old cotyledon explants of Cucumber (Cucumis sativus L) cv Poinsett 76 were cocultivated with two Agrobacterium strains (EHA105 and LBA 4404) each carrying GUS as the reporter gene and npt-II as the selection marker gene in the T-DNA region of the vector. Transformed shoots were selected at 150 mg/L kanamycin. A two day cocultivation coupled with $20\;{\mu}M$ acetosyringone increased the frequency (8.2 and 15.4 shoots) of GUS expression in the shoots of transformed plant. Among the two Agrobacterium strains, EHA 105 performed better than LBA 4404 in bringing two-fold increase in transformation efficiency (14%) than LBA 4404 (7.4%). PCR analysis was done to confirm the integration of T-DNA into cucumber genome.

• Agricultural and Biosystems Engineering
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• v.2 no.2
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• pp.75-80
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• 2001

This paper describes method to diagnose abiotic stresses such ad low root temperature, low light intensity and high salinity in cucumber plants with several physiological instruments. The stresses could be detected by measuring and analyzing the differences in chlorophyll content, temperature difference between leaf and atmosphere and light absorptance at wavelengths of 480, 560, 710, 1420 and 1650nm. It was concluded that the stresses could be first diagnosed from the 3rd to 10th day after treatment and the overall accuracy of diagnosis was estimated between 25 and 75%. near-infrared spectrometer showed better and earlier detection than the other instruments investigated.

• Agricultural and Biosystems Engineering
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• v.2 no.1
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• pp.1-6
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• 2001

This paper represents methods to diagnose nutrient deficient stresses of cucumber plants using several physiological instruments. The stresses could be detected by measuring and analyzing the difference of chlorophyll content, photochemical efficiency (Fv/Fm), temperature difference (DT) and light absorbance at wavelengths of 480nm, 560nm and 710nm between deficient and control plants. From the all over experiments, the stresses could be first diagnosed in the 3rd to 5th day in general after treatment and the overall diagnosis rate was estimated at more than 50% up to 100%.