• Korean Journal of Agricultural and Forest Meteorology
• /
• v.4 no.2
• /
• pp.72-79
• /
• 2002

This study was conducted to compare the physiological and biochemical responses of four Betula species in response to ozone, and to find out the relationship between ozone uptake rate and photosynthesis or antioxidant activity. One-year-old seedlings of four Betula sp, B. costata, B. davurica, B. platyphylla var, japonica, and B. ermani, exposed to 100 pub ozone concentration for 8h day$^{-1}$ for 5 weeks in fumigation chamber. Ozone uptake rate, photosynthesis, SOD and GR activity were measured in the leaves of four species once a week. Cumulative ozone uptake rate was largest in the loaves of B. costata(53.8 mmol m$^{-2}$ ), smallest in the leaves of B. davurica(35.5 mmol m$^{-2}$ ). Photosynthesis of four Betula sp. exposed to ozone reduced relative to control, but the photosynthetic responses with changing stomatal conductance were different among species. Ozone exposure increased SOD activities of four species at the early exposing period, but after a critical point SOD activity decreased gradually. GR activity of B. costata was similar to the change of SOD activity, but the others showed the different patterns from B. costata. In conclusion, decreasing both SOD and GR activity at the critical point, B. costata may be sensitive species in response to ozone. In contrast, the others may be resistant species, which gradually increase GR activity following ozone exposure. GR activity was not always in accord with the change of SOD activity against ozone uptake, and the different responses between species were supposed to be affected by the cumulative ozone uptake.

• Korean Journal of Plant Tissue Culture
• /
• v.26 no.3
• /
• pp.183-187
• /
• 1999

To establish an efficient screening system for new herbicides using plant cultured cells, responses of tobacco photomixotrophic cultured (PH) cells to various herbicides with different modes of action were surveyed by measuring the cell growth and ion conductivity in medium. The cells were cultured in Murashige and Skoog (MS) medium containing 0.7mg/L 2,4-D, 0.3mg/L kinetin and 30 g/L sucrose at $25^{\circ}C$ in the light (100 rpm). Chemicals were treated to suspension cultures of tobacco PH cells at the time of subculture. The cell growth and ion conductivity in the medium were investigated on 12 days after chemical treatment. The ion conductivity assay gave well correlated results to the cell growth inhibition data. The responses of tobacco PM cells were dependent on the modes of action of chemicals tested. Atrazine, an inhibitor of photosynthetic electron transport (PET), strongly inhibited both the cell membrane and cell growth ($IC_{50}$/, about 1 $\mu$M). Butachlor (an inhibitor of cell division), glufosinate (an inhibitor of amino acid biosynthesis), and fluridone (an inhibitor of carotenoid biosynthesis) showed a dose-dependent inhibition. However, Quinclorac, a herbicide with an auxin activity, did not affect the cell growth and ion leakage. These results suggested that tobacco PM cells is suitable materials for the simple screening of new herbicides such as PET, amino acid biosynthesis, ceil division inhibitors by measuring the cell growth and ion conductivity.

• Journal of Korean Society of Forest Science
• /
• v.97 no.5
• /
• pp.508-515
• /
• 2008

Sycamore (Platanus occidentalis L.) seedlings were grown under low light intensity and ozone treatments to investigate the role of the light environment in their response to chronic ozone stress. One-year-old seedlings of Platanus occidentalis L. were grown in pots for 3 weeks under low light (OL, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and high light (OH, $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) irradiance in combination with 150 ppb of ozone fumigation. After three weeks of ozone and light treatment, seedlings were placed in ozone free clean chamber for 3 weeks for recovery from ozone stress with same light conditions to compare recovery capacity. Ozone fumigation determined an impairment of the photosynthetic process. Reduction of leaf dry weight (14%) and shoo/root ratio (17%) were observed in OH treatment. OL treatment also showed severe reductions in leaf dry weight and shoot/root ratio by 48% and 36% comparing to control, respectively. At the recovery phase, OH-treated plants recovered their biomass, whereas OL-treated plant showed reduction in leaf dry weight (52%) and shoot/root ratio (49%). OH-treated plants reached similar relative growth rate (RGR) comparing to control, whereas OL-treated plants showed lower RGR in stem height. However, there were no significant differences in response to those treatments in stem diameter RGR at the recovery phase. Ozone treatment produced significant reduction of net photosynthesis in both high and low light treatments. Carboxylation efficiency and apparent quantum yield in OL-treated plants showed significant reductions rate to 10% and 45%, respectively. At the recovery stage, ozone exposed seedlings under high light had similar photosynthetic capacity comparing to control plants. Antioxidant enzymes activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) were increased in ozone fumigated plants only under low light. The present work shows that the physiological changes occur in photosynthesis-related parameters and growth due to ozone and low light stress. Thus, low light seems to enhance the detrimental effects of ozone on growth, photosynthesis, and antioxidant enzyme responses.

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

• Korean Journal of Environmental Agriculture
• /
• v.33 no.4
• /
• pp.372-380
• /
• 2014

BACKGROUND: This study was carried out in order to closely examine the influence of fertilization upon growth in container of seedling in indeciduous Quercus species (Q. mysinaefolia, Q. acuta and Q. glauca). METHODS AND RESULTS: Fertilizer level was made by adjusting water soluble compound fertilizer (N:P:K=19: 19:19, v/v) to 1000, 2000, $3000mg{\cdot}L^{-1}$ level along with non-fertilizing plot. Fertilization increased height, root collar diameter growth, and dry weight in these three species of trees. The more increase in fertilizer level led to the more rise even in growth of these species. H/D ratio and T/R ratio also showed tendency of getting bigger in the more rise in fertilizer level. Photosynthetic rate was shown to get higher in the higher fertilizer level according to fertilization in all the three species. In the analysis of root morphological traits, the total root length was surveyed to be longer in the more rise in fertilizer concentration. As even a case of root project area, surface area, and root volume is the similar tendency to characteristics in the total root length, a rise depending on fertilization was observed. CONCLUSION: In light of the results in this experiment, the fertilizer level is judged to be $2000mg{\cdot}L^{-1}$ level that is proper for production of 1-year-old container seedling in indeciduous Quercus species with excellent root development and high seedling quality index.

• Horticultural Science & Technology
• /
• v.34 no.5
• /
• pp.719-726
• /
• 2016

The effect of high and low temperatures on seedling quality while raising of paprika (Capsicum annuum L.) seedlings, and their early development after planting was investigated. The control raising seedling temperature (RST) was $23^{\circ}C$; high temperature, $31^{\circ}C$; and low temperature, $15^{\circ}C$ throughout the raising seedling period. At $15^{\circ}C$ and $30^{\circ}C$, plant height, stem diameter, fresh weight, dry weight, number of leaves, and seedling leaf area were significantly lower than those at $23^{\circ}C$. At 4 weeks after planting, seedling's growth characteristics showed a similar pattern. Compared to $23^{\circ}C$, seedlings raised at $15^{\circ}C$ and $30^{\circ}C$ had an increased dry weight and leaf area per unit time after planting than during the seedling raising period. At 4 weeks after planting, crop growth rate and leaf area index were unaffected by RST, and relative growth rate and net assimilation rate at RSTs of $15^{\circ}C$ and $31^{\circ}C$ were higher than those those at RST of $23^{\circ}C$. At an RST of $15^{\circ}C$, growth speed and net assimilation rates were higher after planting than before planting, according to increased photosynthetic rate. Thus, high and low temperatures during the seedling raising period significantly reduced seedling growth and plant growth after planting. After planting, seedlings raised at $15^{\circ}C$ recovered more quickly than did those raised at $31^{\circ}C$.

• Journal of Bio-Environment Control
• /
• v.4 no.1
• /
• pp.9-16
• /
• 1995

The effect of day and night temperature on the seedlings growth as well as physiological responses of red pepper seedlings to temperature, such as uptake of water and nutrients, rates of photosynthesis and respiration of leaf and root were also investigated in growth cabinet. The results obtained were as follows ; 1. As the temperature dropped down to 12$^{\circ}C$, the uptake of water and nutrients, nitrate, phosphorus and potassium were decreased drastically. At 5$^{\circ}C$ there was virtually no uptake of water and nutrients. 2. Photosynthetic activity in the leaves of red pepper seedlings was increased gradually from 5$^{\circ}C$ to $25^{\circ}C$ and observed the highest photosynthetic activity at $25^{\circ}C$, but respiratory activity of leaf increased up to 3$0^{\circ}C$ and the same trend was observed in root respiratory activity. 3. Optimal combination of day and night temperature for shoot dry weight which is the decisive criterion of good seedlings of red pepper was found to be $25^{\circ}C$ at nighttime and 3$0^{\circ}C$ at daytime and then day/night temperature showed in the order of 25/25, 30/15, 15/25, 10/$25^{\circ}C$. No increment of shoot dry weight at 5$^{\circ}C$ in nighttime temperature observed regardless of daytime temperature.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.2
• /
• pp.106-112
• /
• 2012

In order to understand the growth and ecophy -siological response of ginseng to global warming condition, we cultivated one and two year ginseng seedlings in control (ambient $CO_2$ + ambient temperature) and global warming treatment (elevated $CO_2$ + elevated temperature) from March 2010 to July 2011. Shoot appearance and initiation of flowering were advanced by 3-4 days in global warming treatment than in control. However, timing of fruit setting and seed ripeness was similar in both control and global warming treatment. Shoot length was longer in global warming treatment than in control, and also the number of leaves was much in global warming treatment. Fresh root weight was not different between control and global warming treatment. Photosynthetic rate was higher in global warming treatment than at control. Photosynthetic rate and transpiration rate were higher in two year seedlings than in one year seedlings at control, but was not different between seedling age of ginseng in global warming treatment. Water use efficiency was higher in one year seedlings than two year seedlings at control and global warming treatment. These results demonstrated that Korean ginseng more or less positively responds to global warming situation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.1
• /
• pp.11-15
• /
• 2005

This experiment was conducted to investigate the changes of growth and maturity and to clarify the function of supernodulating characters, excessive nodules and high biological nitrogen fixation rate (BNF), on maturity in response to different planting time in supernodulating soybean mutants. Two supernodulating soybean mutants, Sakukei4 and SS2-2, and their parent cultivars, Enrei and Shinpaldalkong2, were planted on May 24 and June 15, 2004. The degrees of the shortening of growth days by the planting time delay were 18 to 22 days in four cultivar, and there were no significant differences among the cultivars. However, four cultivars showed the different maturity properties. Sakukei4, mutated from Enrei, showed later maturity than that of Enrei, and 882-2, mutated from Shinpaldalkong2, showed earlier maturity than that of Shinpaldalkong2. The plant and nodule dry weights at R6 stage of Sakukei4 showed the smallest decrement and those of SS2-2 was showed the largest decrement by the delay of planting time. The photosynthetic rates of Sakukei4 during the late reproductive growth period were slowly decreased, however those of SS2-2 were steeply decreased in two planting time treatments. Overall, the growth of Sakukei4 was decreased slowly, however the growth of SS2-2 was decreased sharply according to the delay of planting time. The percentage of seed yield of Sakukei4 in June planting plot compared with May planting plot at R8 stage was $92\%$, which was the lowest decreasing rate of yield among the cultivars, and in the case of SS2-2, it was in $76\%$, the highest one. These results indicated that the responses of supernodulating mutants by the delay of planting time were very similar to the wild types. This means supernodulating characters in supernodulating soybean mutants might not affect to the maturity property. Additionally, the maturity property could be considered as an important characteristics to decide or to select on the developments of supernodulating soybean mutants, which have a low productivity by an excessive nodules, especially.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.45 no.1
• /
• pp.28-34
• /
• 2017

This study was carried out to investigate growth characteristics of woody plants that are widely used indoors in accordance with irrigation frequency and to find the optimum irrigation conditions for plants that help to improve the indoor environment. Four woody plants used in this study included Ardisia pusilla, Clusia rosea, Fatsia japonica, and Ficus elastica. They were planted in pots with a diameter of 10cm and cultivated in three different irrigation frequencies: two times per week, one time per week, and one time per two weeks. After 120 days, they were measured by plant height, fresh weight, dry weight, SPAD value, leaf color, leaf water potential, chlorophyll fluorescence (Fv/Fm), and photosynthetic rate. The average soil moisture content was $48.8{\pm}2.1%$ in two times per week, $25.2{\pm}4.4%$ in one time per week, and $10.3{\pm}2.4%$ in one time per two weeks. For A. pusilla, leaf water potential was higher, and Fv/Fm value was 0.731 in two times per week irrigation, showing more wetness. For A. pusilla, F. japonica and F. elastica photosynthetic rate was significantly lower in one time per two weeks irrigation, appearing to be more sensitive to drying than C. rosea. When irrigated one time per week, with the soil's volume average moisture content of 25%, all four woody plants used in this experiment proved to grow smooth. Thus, it was determined to be good for use in indoor landscaping.