• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.123-133
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• 2011

The objective of this study was to find optimal nutrient condition of container seedling production of two tropical species for high seedling quality. This study was conducted to investigate photosynthesis, chlorophyll fluorescence, chlorophyll contents, and growth performances of container seedlings of Eucalyptus pellita and Acacia mangium growing under four different fertilization treatments (Con., $0.5\;g{\cdot}l^{-1}$, $1.0\;g{\cdot}l^{-1}$, and $2.0\;g{\cdot}l^{-1}$ fertilization). E. pellita showed outstanding photosynthetic capacity, photochemical efficiency, and chlorophyll contents at $1.0\;g{\cdot}l^{-1}$ fertilization. Meanwhile, E. pellita showed the highest photosynthetic capacity, photochemical efficiency, and chlorophyll contents at $2.0\;g{\cdot}l^{-1}$ fertilization, as fertilization rate were increased, those of A. mangium increased. Like physiological characteristics, Both E. pellita at $1.0\;g{\cdot}l^{-1}$ fertilization and A. mangium at $2.0\;g{\cdot}l^{-1}$ fertilization were higher root collar diameter, height, biomass, and seedling quality index than other treatments. These results showed that E. pellita at $1\;g{\cdot}l^{-1}$ fertilization and A. mangium at $2.0\;g{\cdot}l^{-1}$ fertilization is optimal nutrient condition, respectively. Moreover, fertilization rate controlling is very important for growth and seedling quality of container seedling.

• 한국해양학회지
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• v.28 no.1
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• pp.52-68
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• 1993

Effects of iron and/or chelator addition on primary production in the equatorial Upwelling system were studied during the TOGA(Tropical oceans and Global Atmosphere) and EPOCS (Equatorial Pacific ocean Climate Studies) cruises in June and November-December of 1989. Changes in the phytoplankton biomass and the degree of iron stress were estimated using the changes in vivo fluorescence before and after the addition of DCMU, which is an inhibitor of photosynthetic electron transposer system. Nitrate uptake was measured using /SUP 45/N labeled KNO$_3$ to estimate the new production. When samples were taken from the Upwelling area where nitrate concentration was higher than 5 uM, there were significant differences between the control and cheated iron treatments in vivo fluorescence and in nitrate uptake capacity. However, CFC (Cellular fluorescence capacity) did not show any significant difference between the control and treatments until nutrient limitation becomes severse and cells become shifted-down. Outside of the Upwelling area where surface nitrate concentration was low (below 0.5 uM), there was no significant difference between the control and treatments in vivo fluorescence and CFC. It is evident that primary and new production in the equatorial Pacific Upwelling region are limited by the availability of iron. However, the physiology of phytoplankton indigenous to this region does not appear to be iron stressed judging from CFC values.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.500-509
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• 2014

To prevent freezing of the road by fallen snow, Calcium chloride($CaCl_2$) as a deicer is used to very often and it can be harmful to roadside trees. This study was conducted to investigate the effects of Calcium chloride($CaCl_2$) as a deicer on growth and physiological traits of Acer triflorum according to different concentration of $CaCl_2$. We measured growth, chlorophyll contents, gas exchangement characteristics, chlorophyll fluorescence and mineral nutrition concentration in plant and soil. The experimental group was composed of four treatments including 0mM(control), 9mM(0.5 %), 18mM(1.0 %), 54mM(3.0 %). Before germinating new shoot, the dissolution of $CaCl_2$ was irrigated twice interval of a week. At 30 days after treatment, all treatments decreased total cholorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and photochemical efficiency($F_v/F_m$) with increasing concentration of $CaCl_2$ and especially, they significantly reduced in 3.0 % treatment. In contrast, chlorophyll a/b ratio increased with an increase of $CaCl_2$ concentration and water use efficiency increased in 1.0 % and 3.0 % treatments. At 50 days after treatment, all treatments were decreased in chl a, chl b, total chlorophyll content, carotenoid content, photosynthetic capacity, photochemical efficiency($F_v/F_m$) and quantum yield of photosystem II(${\Phi}_{PSII}$) compared with control and 3.0 % treatments were withered. $Ca^{2+}$ and $Cl^-$ were accumulated in leaves and soil, which inhibited water absorption and electron transport and it caused the reduction of height growth rate more than 50 %. Although there was a little difference according to time and $CaCl_2$ concentration, all treatments decreased in growth rate and physiological activity slowed down. As time passed, these results got worse. Therefore we need to take a measure earlier in order to minimize damage of trees.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.3
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• pp.177-183
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• 2004

The discharge of waste nutrient solution from greenhouse to natural ecosystem leads to the accumulation of excess nutrients that results in contamination or eutrophication. There is a need to recycle the waste nutrient solution in order to prevent the environmental hazards. The amount and kind of nutrients in waste nutrient solution might be enough to grow photosynthetic microorganisms. Hence in the present study, we examined the growth and mass cultivation of cyanobacteria in the waste nutrient solution with an objective of removing N and P and concomitantly, its mass cultivation. Four photosynthetic filamentous cyanobacteria (Anabaena HA101, HA701 and Nostoc HN601, HN701) isolated from composts and soils of the Chungnam province were used as culture strains. Among the isolates, Nostoc HN601 performed faster growth rate and higher N and P uptake in the BG-II ($NO_3{^-}$) medium when compared to those of other cyanobacterial strains. Finally, the selected isolate was tested under optimum conditions (airflow at the rate of $1L\;min^{-1}$. in 15 L reactor, initial pH 8) in waste nutrient solution from tomato hydroponic in green house condition. Results showed to remove 100% phosphate from the waste nutrient solution in the tomato hydroponics recorded over a period of 7 days. The growth rate of Nostoc HN601 was $16mg\;Chl-a\;L^{-1}$ in the waste nutrient solution from tomato hydroponics with optimum condition, whereas growth rate of Nostoc HN601 was only $9.8mg\;Chl-a\;L^{-1}$ in BG-11 media. Nitrogen fixing capacity of Nostoc HN601 was $20.9nmol\;C_2H_4\;mg^{-1}\;Chl-a\;h^{-1}$ in N-free BG-11. The total nitrogen and total phosphate concentration of Nostoc HN601 were 63.3 mg N gram dry weight $(GDW)^{-1}$ and $19.1mg\;P\;GDW^{-1}$ respectively. Collectively, cyanobacterial mass production using waste nutrient solution under green house condition might be suitable for recycling and cleaning of waste nutrient solution from hydroponic culture system. Biomass of cyanobacteria, cultivated in waste nutrient solution, could be used as biofertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.2
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• pp.126-130
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• 1985

Photoinhibition studies were conducted with ginseng (Panax ginseng) grown under shade and tobacco (N. tobaccum cv. Bulgaria) grown under full sunlight. The plants were exposed to light intensity of 580, 1280, 1770, 2580 ${\mu}$E/㎡/sec in normal air for 3.6 9 hours. Light saturation of ginseng was observed at 550 ${\mu}$E/㎡/sec and that of tobacco was at 1600 ${\mu}$E/㎡/sec. Tobacco exposed to high light intensity and long duration of light irradiation didn't show entire reduction in photosynthetic capacity. But in ginseng, 20.3% of photosynthesis was reduced in light intensity of 2,580 ${\mu}$E/㎡/sec during 9 hours. Light response in photosynthesis differed considerably between tobacco and ginseng, and ginseng exposed to high light intensity showed remarkable reduction in photosynthesis. The extent of photoinhibition of ginseng was dependent on the length of exposure to the high light intensity. Stomatal resistance of ginseng seemed not to be changed by photoinhibition but mesophyll resistance was increased.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.4
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• pp.180-191
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• 2015

Marine environmental characteristics and primary productivity of phytoplankton were investigated in seaweed bed of northwestern coast of Jeju Island during Autumn, 2014. The trophic state based on dissolved inorganic nitrogen and phosphorus was mesotrophic. The Redfield ratio was less than 16, indicating that nitrogen was the limiting factor for the growth of phytoplankton. Dissolved organic nitrogen and phosphorus accounts for 63 and 46% of the dissolved total nitrogen and phosphorus, respectively. Light utilization efficiency (${\alpha}$) and maximum photosynthetic capacity ($P_m{^B}$) were highest in the Donggwi (third-year marine forest), followed by Gonae (one-year marine forest), Biyangdo (natural seaweed bed) and Geumneung (whitening area). The primary productivity of phytoplankton in the Donggwi, Gonae and Biyangdo also was higher than that in the Geumneung. Although nitrogen is the limiting factor, enriched dissolved organic nitrogen might play an important role to maintain primary productivity. In addition, phytoplankton community through photosynthesis could produce about 14% of phytoplankton carbon in one hour. These results will be able to use the important information for material cycle and ecological valuation of seaweed bed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.133-133
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• 2017

Lodging is one of the important constraints in rice production. The lodging destroys the canopy structure, and sharply reduces the capacity of photosynthetic rate and dry matter production. In cereal crops, stem lodging can be classified into two types: stem breaking type and stem bending type. To improve stem lodging resistance, it is important to reveal strong culm traits of superior lodging resistant varieties. There are large varietal differences in parameters associated with the bending moment at breaking (M) and flexural rigidity (FR). The indica variety Takanari possesses large M due to its large section modulus (SM) despite of its small bending stress (BS), while Takanari also has large FR due to its large secondary moment of inertia (SMI) and Young's modulus (YM). To identify quantitative trait loci (QTLs) and the corresponding genes associated with the parameters for M ($=SM{\times}BS$) and FR ($=SM{\times}YM$) should enable to develop lodging resistant varieties, efficiently. In order to identify QTLs for cell wall materials such as cellulose, hemicellulose and lignin associated with BS and YM, a set of Chromosome Segment of Substitution Lines (CSSLs) consisted of 37 lines with chromosome segments of Koshihikari in the genetic background of Takanari were used. Takanari had large M and small BS as compared with Koshihikari. The QTLs for BS were estimated on chromosomes 3, 5, 6, 8, 9, 10, 11 and 12. Koshihikari alleles increased BS in these QTLs. Takanari had a large FR due to its large SMI and YM as compared with Koshihikari. The YM was increased by substitution of the Koshihikari chromosomal segments on chromosomes 2, 10 and 11. Other QTLs estimated on chromosomes 7 and 12 that Koshihikari alleles contributed to the decrease of YM. For lignin, only one major QTL for lignin density was detected on chromosome 11. Hollocellulose densities were increased by the substitution of Koshihikari segments on chromosomes 5 and 11. On the other hand, these were decreased on chromosomes 1 and 3 by substitution of Koshihikari segments. QTLs for cellulose density were estimated on chromosomes 1, 3 and 5 by substitution of Koshihikari segments. For hemicellulose, QTL on chromosome 3 showed that hemicellulose density decreased by the substitution of Koshihikari segment. However, hemicellulose densities on chromosomes 5, 8 and 11 showed the opposite effects. The QTLs for hemicellulose, cellulose, and hollocelulose densities identified on chromosome 5 overlapped with that for bending stress, indicating the positive effect of Koshihikari segment on increasing bending stress. These results suggest that some QTLs for the densities of cell wall materials contribute to increasing bending stress and Young's modulus, and could be utilized to improve the lodging resistance for both types of breaking and bending in rice varieties.

• Applied Microscopy
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• v.25 no.4
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• pp.52-61
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• 1995

Ultrastructural characteristics were examined with leaves of three species, O. japonicus A. Berger, O. malacophyllus Fisch., and O. sikokianus Owhi that probably have CAM mode. The mesophyll cells of these Orostachys possessed vacuoles with precipitates, myelin-like figures, and plasmalemmasomes, along with typical chloroplasts, microbodies and darkly stained bodies in their thin peripheral cytoplasm. Separation of the plasmalemma from the cell wall, leaving a space between them, was a common phenomenon in these species. A complex array of small to large vacuoles which contain small, membrane-bounded vesicles or vacuole-like structures were frequently found. A well-developed thylakoid system was observed in the chloroplasts and this indicates that the photosynthetic capacity of these mesophyll cells is probably active. A peculiar configuration of cytoplasm, especially around the chloroplasts, was also encountered. The variety of cytoplasmic constituents and vacuoles suggest the water-storing mesophyll cells may be complex in function. Some cellular features detected in this study strongly suggest the possible occurrence of CAM mode in Orostachys species.

• Korean Journal of Weed Science
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• v.15 no.3
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• pp.224-231
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• 1995

Paraquat, the representative bipyridilium herbicide, has high phytotoxic activity through generating toxic oxygen species such as superoxide, hydrogen peroxide and hydroxy radical. The response patterns of plants to paraquat were various. It was assumed that the different response was derived from different antioxidative mechanisms including antioxidative enzymes and antioxidant. Paraquat treatment increased reducing sugar content and malondialdehyde formation at 35 days after treatment in a dose-dependent manner but chlorophyll content decreased. Glutathione content increased by paraquat treatment and tolerant species showed more glutathione content than susceptible species. Superoxide dismutase activity increased with the increase in paraquat concentration and that was higher in tolerant species than susceptible species. Photosynthetic activity(PSII activity) was affected by paraquat, so the susceptible species showed more reduced oxygen evolving capacity than tolerant species. Catalse, NADPH-cytochrome C reductase, and malate dehydrogenase, the enzymes tested in this study, showed that the activities decreased by paraquat treatment. Further studies are necessary to determine whether antioxidative system cause the tolerance to paraquat.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.1
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• pp.28-38
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• 2012

This study was conducted to investigate growth performance, photosynthesis, water use efficiency (WUE), and stomatal conductance ($g_s$) of container seedlings of Liriodendron tulipifera and Zelkova serrata growing under three different irrigation periods (1 time/1 day, 1 time/2 days and 1 time/3 days) for high seedling quality. The root collar diameter and height of L. tulipifera and Z. serrata seedlings were highest with 1 time/1 day irrigation, whereas they were lowest with 1 time/3 days irrigation. The two species showed low drought tolerance. As irrigation period was shortened, biomass and seedling quality index (SQI) of the two species increased. The ratio of height to root collar diameter (H/D) and the ratio of below to aboveground biomass (T/R) of the two species were lower with 1 time/3 days than at other irrigation periods. L. tulipifera and Z. serrata seedlings showed significantly higher photosynthetic capacity with 1 time/1 day irrigation. As irrigation period was shortened, $g_s$ of two species increased, while their WUE decreased significantly (P<0.05) These results show that 1 time/1 day irrigation provides the most optimal water condition for container seedling production of two species and irrigation controlling is very important for growth and quality of container seedlings.