• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.11-11
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• 2021

Ferns have been consumed as food in many countries for centuries. As rich sources of protein, fiber, minerals, vitamins, essential amino acids, and fatty acids, ferns provide important nutrients to humans. Eastern bracken (Pteridium aquilinum var. latiusculum (Desv.) Underw. ex A. Heller) is the most popular edible fern in South Korea where, additionally, it has long been used as an edible wild leaf vegetable. Recently, the production of eastern brackens in South Korea (2018) has reached 14,032 tons, for an annual revenue of 83.5 billion won, and even more eastern brackens are marketed if imports are taken into account as well. Most of the common ferns can be propagated using spores. However, fern farmers cultivate seedlings through traditional propagation methods, such as root pruning or rhizome division. These propagation methods exhibit limitations in forming roots and growing-points and are labor intensive. Quality seedlings of eastern bracken can be obtained through spore propagation, but the spores are fine and difficult to handle in the field. In addition, it would require appropriate environmental control. The production of synthetic seeds using encapsulation technology is easy to establish and it can be used to achieve high productivity at low cost. Synthetic seeds contain explants embedded into a seed foam, and they overcome the limitations of micropropagation and offer the possibility of using plug seedlings. Synthetic seed matrix, such as sodium alginate, has the advantages of low cost, low toxicity, and gel stability. The present study aimed to develop and produce synthetic seeds for the commercial exploitation of eastern bracken. Furthermore, we verified spore germination and the extent of gametophyte and sporophyte development achieved with our new synthetic seeds, whose production was intended to solve current problems with the handling, storage, and transportation of eastern bracken.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.311-316
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• 2011

This study aimed to determine the effect of EC (electrical conductivity) levels of nutrient solution in hydroponic culture on allyl-isothiocyanate (AITC) content within plant tissues, Vitamin C content and physiological responses in wasabi plant (Wasabia japonica M. 'Darma'). The 'Darma' was grown for 5 weeks with a deep flow technique (DFT) system controlled at 5 different EC levels, including 0.5, 1, 2, 3, and $5dS{\cdot}m^{-1}$. In result, the highest total content of AITC showed at EC level 5 and $3dS{\cdot}m^{-1}$ for 1 or 5- week, respectively. The total content of AITC increased about 1.2-1.4 times when the plants were grown in the EC levels between 0.5 and $2dS{\cdot}m^{-1}$, whereas the content decreased about 6 and 56 % in the EC level 3 and $5dS{\cdot}m^{-1}$, respectively. The content of AITC was relatively higher in petiole tissue, about 53 %, taken from 1 week-grown plants when the EC was controlled between 0.5 and $2dS{\cdot}m^{-1}$. Root tissue also had relatively higher content of AITC, about 45.1 %, when the EC was controlled at 3 and $5dS{\cdot}m^{-1}$. However, a 5-fold decrease in the AITC content was found in blade tissue and a 6.8-fold decrease in root when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. There was no significant difference in the vitamin C content in 1-week grown leaf tissues under the different EC level treatments; but, the content increased about 27% in 5-week grown plants at the EC level between 0.5 and $2dS{\cdot}m^{-1}$, compared to the 1 week-grown leaf tissue. Electrolyte leakage of leaf tissue taken from 3-week grown plant was 3-fold higher at the EC level $5dS{\cdot}m^{-1}$, compared to the EC level between 0.5 and $2dS{\cdot}m^{-1}$. Chlorophyll content, photosynthesis rate and transpiration rate were decreased when the EC was controlled at higher than $2dS{\cdot}m^{-1}$. Leaf water content, specific leaf area and growth were decreased when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. All the integrated results in this study suggest that the EC level of nutrient solution should be maintained at lower than $3dS{\cdot}m^{-1}$ in order to improve nutritional value and quantity required for hydroponically grown wasabi as functional vegetable.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.964-972
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• 2010

Objective of this research was to determine the influence of physico.chemical properties of root substrates on growth of daughter plants that were developed through plastic bag cultivation of mother plants in 'Seolhyang' strawberry propagation. Six different formulations of root substrates for daughter plant cultivation were peatmoss + vermiculite (5:5, A), peatmoss + perlite (7:3, B), coir dust + perlite (7:3, C), coir dust + peatmoss + perlite (3.5:3.5:3.0, D), rice-hull + coir dust + perlite (2:7:1, E), and rice hull + coir dust (3:7, F). The 10 cm plastic pots filled with formulated substrates were located near the plastic bag where mother plants were growing. Then the runners and daughter plants originated from mother plants were fixed on each root substrate filled into 10 cm plastic pot and daughter plants were grown in the plastic pots. The container capacity and air space showed big differences among substrates tested. The substrates E and F had the less container capacity and the higher air space than other substrates tested. This indicates that the two substrates would have difficulties in water managements during the raising of daughter plants. The substrates of A, B, and D which contained peatmoss in formulation had higher nitrogen concentrations than those containing coir dust or rice hull. The substrates of E and F which contained rice hull had lower nitrogen, phosphorus and potassium concentrations than those that contained coir. The crown diameters of daughter plants grown in substrate A were around 13 mm which is thicker than those grown in other substrates. The fresh weights of daughter plants grown in A substrate were the heaviest followed by C, F, D, E, and B. The dry weight of daughter plants showed similar tendency to those of fresh weight. The daughter plants which had heavy fresh and dry weights and thick crown diameter are considered good seedlings. Based on this justification, the substrates of A, C and F are acceptable for daughter plant growth of 'Seolhyang' strawberry.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.200-208
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• 2004

Effects of cucumber and tomato seed germination by previous leaf and root vegetables (cabbage, radish, welsh onion, lettuce) residue in soil were tested in pot condition. Overall, suppression effect of welsh onion residue was the greatest in 4 tested crop residue and followed by radish, cabbage and lettuce, but lettuce residue didn't have effect on cucumber seed germination. Suppression were maintained ca. 20 days but after the time point, growth of cucumber and tomato were enhanced. Enhancing effect of welsh onion residue was the greatest in 4 tested crops residues and followed by radish, cabbage and lettuce. As a conclusion, residue of welsh onion, radish and cabbage were suppressed the germination of cucumber and tomato seeds but enhanced growth after 20 days of treatment. To verify the effective concentration of residue on suppression of germination and growth of radicle of cucumber and tomato, plant extract of welsh onion, radish, cabbage and lettuce were diluted as 5, 10, 17, 23, 35, 50, and $65\%$, and then tested. In low concentration treatment, 5, 10, 17, and $23\%$, all 4 crop extracts didn't suppress cucumber seed germination. High concentration of lettuce extract, 35, 50, and $65\%$, cucumber seed didn't germinate at all. In case of welsh onion extract, only $65\%$ treatment suppressed cucumber seed germination. In low concentration treatment, 17, and $23\%$, only the welsh onion extract suppressed young radicle. In case of high concentration treatment, except $35\%$, all four crops extract suppressed cucumber radicle growth. In low concentration treatment, tomato seed germination was suppressed by lettuce extract only but in high concentration treatment, 35, 50, and $65\%$, all extracts suppressed germination. Especially higher than $50\%$ treatment, tomato seed didn't germinate at all. Radicle growth was highly suppressed in welsh onion and lettuce extract, higher than $23\%$ concentration. As conclusion, leaf and root vegetable extracts suppressed cucumber and tomato seed germination and in high concentration, also suppressed radicle growth.

• Korean journal of applied entomology
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• v.20 no.3 s.48
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• pp.135-145
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• 1981

Vegetables including Chinese cabbage and radish have been grown in alpine areas such as Muju, Namweon, Jinan and Jangsu during the shortage period of vegetables. The incidence of various diseases, environmental factors such as temperatures and rainfalls, and aphid populations as virus vector were observed at 10-day intervals from July to September in those areas. Disease incidence showed no significant difference among locations. Major diseases in Chin ese cabbage were bacterial soft rot, white spot, downy mildew, mosaic virus, Alternaria leaf spot and Fusarium seedling blight. Major diseases in radish were virus, white rust, black rot, root rot, leaf spot and Fusarium seedling blight. Disease incidence reached peak on Aug. 20 with $27\%$ infection in radish and with $20\%$ infection in Chinese cabbage during the growing season, and declined thereafter. Percentage of infection in each growth stage showed $25\%$ at root thickening stage and $26\%$ at the harvest time in radish; and the head formation stage, $24\%$ at the harvest time. The data indicate that disease incidence in radish increased rapidly at late growing stage and progressively increased in Chinese cabbage Seedling blight caused by Fusarium sp. and root rot caused by Aphanomyces sp. were also observed in those areas. Cool and wet weather appeared to be favorable for disease incidences during the rainy period of growing season although average temperature was about $25^{\circ}C$. Populations of aphids were lower in the alpine vegetable growing area than that of flat areas. Aphids as virus vectors from total aphids collected were $73.5\%$ or 289 virus vectors /993 total aphids in Namweon and $18.1\%$ or 31 virus vectors/171 total aphids in Muju. The most prerevalent species of aphids was Myzus persicae Sulz.

• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.161-168
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• 2011

The purpose of this study was to evaluate microbiological contamination of fresh vegetables in Korea. Twenty types of vegetables were tested for total aerobic bacteria, coliforms, Escherichia coli, yeast and mold, and pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Salmonella, E. coli O157:H7, Cronobacter sakazakii, Shigella, and Campylobacter. Levels of total aerobic bacteria and coliform on 20 vegetables were between 3.74 and 8.04 log CFU/g, and 0.16 and 5.02 log CFU/g, respectively. The highest contamination levels of total aerobic bacteria were observed on water dropwort, sprouts, mungbean sprout, and ballflower root. There was no significant difference (p>0.05) in microbial contamination levels of total aerobic count, coliform, E. coli, yeast and mold between organic and nonorganic vegetables. When isolation methods using selective agars were applied, L. monocytogenes, B. cereus, Salmonella and Campylobacter were isolated from some fresh vegetable samples. Results of API kit tests showed that L. monocytogenes was identified on Chinese cabbage, cucumber, soybean sprouts, and iceberg lettuce while Salmonella was identified on Korean leek. Furthermore, Campylobacter jejuni was also identified in more than 50 of the 100 samples. However, when positive samples from API kit were tested for real-time PCR or 16S rRNA sequencing method, only B. cereus from perilla leaf, carrot, water dropwort, and sprouts showed positive results. These results indicate that selective agar and API kit detection methods might result in false positive results for some pathogens. Therefore, studies need to improve isolation or confirmation methods for such pathogens.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.14-21
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• 2022

Uniform scions and rootstocks should be produced to ensure grafting success. Light quality is an important environmental factor that regulates seedling growth. The effects of warm- and cool-white light emitting diode (LED) ratios on seedling growth were investigated. Scions and rootstocks of cucumber, tomato, and watermelon were grown in a closed transplant production system using LED as the sole lighting source. The LED treatments were W1C0 (only warm-white), W1C1 (warm-white: cool-white = 1:1), W3C1 (warm-white: cool-white = 3:1), and W5C2 (warm-white: cool-white = 5:2). The seedlings grown in W1C1 had the shortest hypocotyls, and the seedlings grown in W1C0 had the longest hypocotyls among the three tested vegetables. The hypocotyls of watermelon scions, watermelon rootstocks, and tomato rootstocks were shortest in W1C1, followed by those in W3C1, W5C2, and W1C0, but there was no significant difference between W3C1 and W5C2, which remained the same as the ratio of cool-white LEDs increased. In addition, tomato scions had the first and second longest hypocotyls in W1C0 and W3C1, respectively, and the shortest hypocotyls in W5C2 and W1C1, along with W5C2 and W1C1, although the difference was not significant. The stem diameter was highest in W1C0 except for tomato seedlings and rootstocks of watermelon. The shoot fresh weight of scions and rootstocks of cucumber and watermelon and the root fresh weight of cucumber scions were lowest in W1C1. These results indicated that different ratios of LED lighting sources had a strong effect on the hypocotyl elongation of seedlings.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.97-105
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• 2023

Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH₄⁺ and NO₃^-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH₄⁺:NO₃^- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH₄⁺ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH₄⁺ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO₃^- :NH₄⁺ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO₃^- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO₃^- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.78-85
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• 2016

This study was carried out to determine the effects of shading and leaf mold treatment on growth characteristics and photosynthesis responses of Peucedanum japonicum in forest farming. It is very valuable as a sort of health food, so that the demand for the vegetable has increased recently. The experiment can not only increase the yield but also contribute to the development of eco-friendly technology for high-quality P. japonicum. It was performed by shading treatments (full sunlight, 35%, 50% and 75% shading) and leaf mold treatments (control, pine tree and chestnut tree). Height, stem diameter, root collar diameter, number of stem and dry weight were the highest in chestnut-leaf mold under full sunlight. Leaf area, leaf length and leaf width were the highest in chestnut-leaf mold under 35% shading. Photosynthetic rate, conductance to $H_2O$, transpiration rate and water use efficiency were the highest in chestnut-leaf mold under full sunlight. Specially, photosynthetic rate was higher under chestnut-leaf mold in all shading treatment, and getting lower in the higher shading rate. As a result of surveying the whole experiment, it is concluded that P. japonicum grows nicely by maintaining 35% shading under chestnutleaf mold in forest farming. Thus, it is the most effective way to increase the yield for high-quality P. japonicum with eco-friendly technology.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.781-786
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• 2014

Growth and physiological disorders caused by abnormally low temperatures were evaluated in pepper, an important field crop in Korea. In addition, the effects of chemical treatment using glutamine was verified on minimizing the damages by low temperature. The growth of pepper plants in stem length and diameter was suppressed as the temperature decreased from $25^{\circ}C$, and the suppression level was the highest for plants grown for 90 days at $20^{\circ}C$. However, root growth was not affected by the different temperatures. The number of leaf and leaf area decreased at the temperatures below $25^{\circ}C$, an optimum temperature for growth. Fresh weight and dry weight decreased for plants grown at $20^{\circ}C$. Pepper fruit yield also decreased by 11% at $20^{\circ}C$ in comparison to $25^{\circ}C$. Falling blossom rate was different depending on the growth temperature, and the rate was 27.2% at $25^{\circ}C$, 35.2% at $22.5^{\circ}C$, and 41.0% at $20^{\circ}C$, indicating that falling blossom rate increased as temperature decreased. Different growth temperatures did not affected on the level of symptom of calcium deficiency and Phytopathora blight. Falling blossom was severe at abnormally low temperature of $20^{\circ}C$, but the treatment of glutamine reduced falling blossom rate and increased the yield by 7.0% as compared to control. The optimum concentration of glutamine treatment was 10 mg/L for yields.