• Journal of Bio-Environment Control
• /
• v.32 no.3
• /
• pp.234-241
• /
• 2023

This study was conducted to investigate the growth of lettuce (Lactuca sativa L.) and Korean mint (Agastache rugosa Kuntze) with microbubble in a closed-type plant production system (CPPS) with a deep flow technique (DFT). Lettuce and Korean mint were grown in CPPS for 23 days. Microbubble was treated for 5 minutes daily at 9:00, 13:00, and 17:00 for 16 days. The leaf length, leaf width, leaf area, and fresh and dry weights of lettuce and Korean mint were significantly lower in microbubble than in the control. The total root length, root surface area, and the number of root tips of lettuce and Korean mint were significantly lower in the microbubble than in the control. In the case of average root diameter, there was no difference between the treatments of lettuce. However, Korean mint significantly increased in thickness in the microbubble treatment, indicating variations among the different crops. The results of the research indicated that microbubble treatment in the DFT inhibited plant growth by inducing abiotic stress in lettuce and Korean mint.

• Korean Journal of Environmental Agriculture
• /
• v.41 no.4
• /
• pp.282-287
• /
• 2022

BACKGROUND: Green algae (Chlorella spp.) has been widely used as a biofertilizer to improve the crop yield and quality. However, available information is not enough to verify the mechanism of green algae's beneficial impact on strawberry. This study was conducted to investigate the effect of Chlorella fusca CHK005 application on the growth and nutrient status of strawberry plant and fruit characteristics. METHODS AND RESULTS: A total of 800 seedlings of strawberry variety 'Kuemsil' were planted. Once a week, C. fusca culture solution (1.0 × 10⁷ cells mL^-1) was applied into soil via irrigation in four different concentrations: no application (control), 1/1000 times (× 0.5), 1/500 times (× 1), and 1/250 times (× 2). Result showed that growth of strawberry plant was enhanced by Chlorella application and the highest impact on fresh weight (FW) and chlorophyll content of the plants were observed in × 2 treatment, followed by × 1, × 0.5, and control treatments. The phosphorus (P) concentration in the plant was significantly higher in × 1 and × 2 treatments compared to control. In case of fruit quality, sugar content (°Brix), hardness, and FW were lowest in control, but these values increased as application levels of Chlorella were higher. Also, P and K contents in the fruits increased with increasing the application levels and significant correlation between P content and oBrix in the fruits was found. CONCLUSION(S): Overall, Chlorella application seemed to improve plant growth and fruit quality by increasing the utilization efficiency of P and K in strawberries.

• Horticultural Science & Technology
• /
• v.32 no.2
• /
• pp.142-148
• /
• 2014

Effect of silicon (Si) nutrition on growth and temperature stress tolerance of Nephrolepis exaltata 'Corditas' grown in a soilless substrate was examined. In vitro-grown acclimatized plantlets were transplanted into the pots containing a coir-based substrate. A nutrient solution containing 0, 50, or $100mg{\cdot}L^{-1}$ Si was supplied through a drip-irrigation system. After 5 months of cultiv ation, S i-treated and -untreated p lants were grown at 10, 25, or $40{\pm}1^{\circ}C$ under a 12 h photoperiod with $530{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and 60% RH. After 7 days, chlorophyll content and chlorophyll fluorescence parameters were measured. Silicon nutrition had a negative effect on growth characteristics of N. exaltata 'Corditas'. However, Si-treated plants had more tolerance to temperature stress than the control plants. The Fv/Fm value was not significantly different when the plants were exposed to $25^{\circ}C$. However, significant difference in Fv/Fm was recorded when plants were exposed to 10 or $40^{\circ}C$. Thus, Fv/Fm could be used as an indicator of low and high temperature tolerance in ferns. The present study also suggests that application of Si may be used to enhance temperature tolerance of ferns.

• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.232-236
• /
• 2006

This study was carried out to establish of hydroponic culture system for year-round mass production of yam and for supply of disease-free seed tubers from the superior yam species. There were not difference in tuber weight between 9 hrs photoperiod(640mg) and natural photoperiod(600mg). However, longer photoperiod than 9 hrs such as 12 hrs and 15 hrs decreased tuber weight to 490 and 500g, respectively, which sugested that long photoperiod showed adverse effect for tuber enlargement. Tuber enlargement of Dioscorea opposite according to ionic strength was higher at 50% nutrient of Sanyak's standard solution. The optimal concentration of NAA for the best tuber growth showed at 100mg/L as a 560mg while control showed a relatively lower tuber growth(350mg).

• Research in Plant Disease
• /
• v.12 no.1
• /
• pp.46-50
• /
• 2006

The microorganisms with the antifungal activity against Phytophthora capsici and Colletotrichum acutatum and the plant growth-promoting activity were screened from a forest and natural fields of Gajang-Dong, Sangju-city. One of the isolates, Streptomyces griseofuscus 200401, was selected as a good plant growth-promoting strain in this study. In greenhouse test, the number of leaf, fresh weight, and dry weight of pepper plants, that were grown with treatment of culture suspension or powder containing S. griseofuscus 200401, were higher than those without the bacterial cells. Cultivation of S. griseofuscus 200401 strain for 7 days in a nutrient rich medium produced ammonium chloride up to 0.13 ${\mu}g/ml$ in the culture solution of S. griseofuscus. Treatment of the selected strain significantly reduced the severity of the late blight of pepper plants to show the equivalent disease control activity to chemical fungicide. This study suggests that S. griseofuscus 200401 strain could be a potential biological agent with the biocontrol activity and the plant growth-promoting activity.

• Journal of Biosystems Engineering
• /
• v.27 no.6
• /
• pp.565-572
• /
• 2002

In order to control the root-zone temperature of greenhouse crops in the hydroponics at hot and cold season, heat pump system for cooling and heating was built and tested in this work. The system was air-to-water type and vapour compression type. The heating and cooling mode was selected by the four way valve. Capacity of the compressor was 3.75㎾ and heat transfer area of the evaporator and the condenser were 3.05㎡ and 0.6㎡, respectively. According to the performance test, it could supply heat of 42,360 to 64,372kJ/h depending on the water circulation rate of 600 to 1,500ℓ/h, respectively, when indoor air temperature was 10∼20$\^{C}$. COP of heat pump system was 3.0 to 4.0 in the heating mode. But, COP of the cooling mode was 1.3 to 2.1 at indoor temperature of 20∼35$\^{C}$. The feasibility test in the greenhouse the developed heating and cooling system was installed, showed that the heating cost of the developed system was only about 13% of that of the conventional heating system. The heating cost of the developed system was 367won/day(electric consumption 9.7㎾h/day), while that of the conventional system was 2,803won/day(oil consumption 7.7ℓ/day) at the same heating mode.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.52 no.3
• /
• pp.264-273
• /
• 2007

In order to examine the cross-tolerance of two chilling-tolerant cultivars (Donganbyeo and Heukhyangbyeo) and two chilling-susceptible cultivars (Hyangmibyeo and Taekbaekbyeo) to salt, paraquat, and drought, changes of physiological response and antioxidant enzymes were investigated. The seedlings were grown in a growth chamber until the 4-leaf stage. The seedlings were exposed to chilling at $5^{\circ}C$ for 3 days. For drought treatment, the seedlings were subjected to drought by withholding water from plants for 5 days. For paraquat study, plants were sprayed with $300{\mu}M$ paraquat. For the salt stress, the seedlings were transferred to the Hoagland's nutrient solution containing 0.6% (w/v) NaCl for 4 days. Chilling-tolerant cultivars showed cross-tolerant to other stresses, salt, paraquat, and drought in physiological parameters, such as leaf injury, chlorophyll a fluorescence, and lipid peroxidation. The baseline levels of antioxidative enzyme activities, catalase (CAT) and peroxidase (POX) activities in chilling-tolerant cultivars were higher than in the chilling-susceptible cultivars. However, there were no differences in ascorbate peroxidase (APX) and glutathione reductase (GR) activities between chilling-tolerant and -susceptible cultivars in untreated control. CAT activity in chilling-tolerant cultivars was higher than that in chilling-susceptible cultivars during chilling, salt, and drought treatments, but not during paraquat treatment. However, other antioxidative enzymes, APX, POX, and GR activities showed no significant differences between chilling-tolerant and -susceptible cultivars during chilling, salt, paraquat, and drought treatments. Thus, it was assumed that CAT contribute to cross-tolerance mechanism of chilling, salt, and drought in rice plants.

• Korean Journal of Microbiology
• /
• v.5 no.2
• /
• pp.97-101
• /
• 1967

Up to the present time, there are only three methods by which we can obtain bacteria free crown gall tissue. According to some papers related to this field, the first method is based on the works of Braun(53') who maintained infected plants at 46-47'c for several days. But the method has a problem that very few plants can tolerate this temperature. The second method is based on the well known observation that old tumors appear to be bacteria free at least 1 or 2% of the explants. Also this method is known to us as laborious and time consuming. The third method is the one we were using that was attempting to kill the bacteria with bacteriacidal agent such as Antibiotics. In fact., it is reported that almost complete control of crown gall of tomato was obtained by Blanchard('51) when plants were grown in a nutrient containing Aureomycin(20${\mu}g$/ml) following needle puncture with the gall bacteria. We have been engaged in making the experiment by applying solution of Penicillin, Streptomycin and of Chloramphenicol(Succinate free) to find the strong bacteriacidal agent through the method of disc plate, and to confirm the effect of antimicrobial action through the method of plant tissue culture system without possible injury to the host plant. The result of this report is the fact the strongest bacteriacidal agent among the above three Antibiotics was Chloramphenicol(Succinate free 1000 p.p.m). and that there happened no injury to the tissue cultures in a White's 10X media containing 1000 p.p.m. of Chloramphenicol.

• Journal of Radiation Industry
• /
• v.4 no.4
• /
• pp.307-312
• /
• 2010

Plants have evolved physiological, biochemical and metabolic mechanisms to increase their survival under the adverse conditions. This present study has been performed to select salt-tolerant rice mutant lines through in vivo and in vitro mutagenesis with gamma-rays. For the selection of the salt-tolerant rice mutants, we conducted three times of selection procedure using 1,500 gamma ray mutant lines resulted from an embryo culture of the original rice cv. Dongan (wild-type, WT): first, selection in the a nutrient solution with 171 mM NaCl; second, selection under in vitro condition with 171 mM NaCl; and third, selection in a reclaimed saline land. Based on a growth comparison of the entries, out of the mutant lines, two putative 2 salt tolerant (ST) rice mutant lines, ST-87 and ST-301, were finally selected. The survival rate of the WT, ST-87 and ST-301 were 36.6%, 60% and 66.3% after 7 days in 171 mM NaCl treatment, respectively. The WT and two salt tolerant mutant lines were used to analyze their genetic variations. A total of 21 EcoRI and Msel primer combinations were used to analyze the genetic relationship of among the two salt-tolerant lines and the WT using the ABI3130 capillary electrophoresis system. In the AFLP analysis, a total of 1469 bands were produced by the 21 primer combinations, and 700 (47.6%) of them were identified as having polymorphism. The genetic similarity coefficients were ranged from 0.52 between the ST-87 and WT to 0.24 between the ST-301 and the WT. These rice mutant lines will be used as a control plot for physiological analysis and genetic research on salt tolerance.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.7 no.1
• /
• pp.47-54
• /
• 2005

This study was carried out to establish the hydroponics production method for year-round cultivation of yam and to establish the mass production system of disease-free seed tubers from the superior yam species through water culture. There were no difference in tuber weight between 9 hr photoperiod(640mg) and natural photoperiod(600mg). However, longer photoperiod such as 12hr and 15hr decreased tuber weight to 490 and 500g, respectively, indicating that long photoperiod effects adversely tuber enlargement. Dioscorea opposita which was grown with hydroponics effected markedly tuber enlargement at 50% nutrient of Sanyak's standard solution. Hormone treatment of NAA 100ppm resulted in the best tuber growth(560mg) while control showed a relatively lower tuber growth(350mg).