• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.5
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• pp.145-153
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• 2012

To obtain basic information for evaluating resistance of soil acidification for growth, net photosynthesis, $N_2$ fixation rate and nutrient status of Alnus firma and Alnus hirsuta seedlings grown in brown forest soil acidified with $H_2SO_4$ or $HNO_3$ solution were investigated (control (pH=5.9), LN (pH=5.0; Low levels of Nitric acid), HN (pH=4.0; High levels of Nitric acid), LS (pH=5.0; Low levels of Sulfuric acid), and HS (pH=4.0; High levels of Sulfuric acid)). The shoot dry weight of Alnus firma and Alnus hirsuta and the root dry weight of Alnus hirsuta seedlings grown in the HN, LS and HS were significantly less than that of the seedlings grown in the control. The Chlorophyll a/b ratio in leaves of Alnus firma at LN, LS and HS was significantly lower than that of control. The concentration of N in leaves of Alnus hirsuta at HS was significantly higher than that of control. The net photosynthetic rate of Alnus firma and Alnus hirsuta seedlings at LN and HN was higher than that of control. Based on the results, we concluded that the negative effects of soil acidification due to sulfate deposition are greater than those of soil acidification due to nitrate deposition on growth, net photosynthesis and $N_2$ fixation rate of Alnus firma more than Alnus hirsuta.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.460-464
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• 2003

White spunbonded fabrics has been utilized toy covering in rice seedling nursery. This study, therefore, was carried out to examine the effect of light quality on seedling emergence, growth, morphology, chlorophyll content and photosynthesis to get the information on the color of the fabrics. Blue, red and far-red lights were treated immediately after sowing seeds of three cultivars, Dongjinbyeo, Ilmibyeo and Daesanbyeo. Seedling emergence, growth and morphology, chlorophyll content and photosynthetic rate were measured. Seedling emergence rate of Dongjinbyeo and Daesanbyeo was low under far-red light treatment compared to those under blue and red light ones. Although the rate of Ilmibyeo was not different from three light treatments. Far-red light treatment showed similar response in plant height and leaf length, but yee light increased number of roots. Shoot and root dry weight was the highest in blue and red light treatments, respectively. Total dry weight, however, was the lowest under far-red light treatment. While chlorophyll content and photosynthetic rate of the three cultivars did not showed consistent response, those were the greatest under red light treatment, and were decreased in order of blue and far-red light treatment.

• Korean Journal of Medicinal Crop Science
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• v.10 no.5
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• pp.409-414
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• 2002

This study was carried out in order to investigate the main traits related to photosynthesis by multiple regression analysis. The photosynthetic rate showed more significant increase in shaded leaves of plant than in non-shaded leaves of plant after shading treatment for 44 days. Negative correlation was found between net photosynthetic rate and SLA(specific leaf area). However, the values obtained from the linear equation were different and were highly significance. From the above results, net photosynthetic rate of shading treatment is higher than that of control in the same SLA. We also found that there were correlation between stomatal conductance and SPAD as well as net photosynthetic rate and stomatal conductance. By the multiple regression analysis, SPAD value, SLA, stomatal conductance and leaf water potential showed a higher correlation coefficient of $r=0.848^{**}$. From the results, out of 4 factors(SPAD value, SLA, stomatal conductance, leaf water potential) stomatal conductance was main factor in the view points of partial regressing.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.1-4
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• 2002

The occurrence rate of russet in 'Whangkeumbae' pear showed significant difference by years because the russet occurrence is greatly affected by the amount of rainfall. This study was conducted to analyse the relationship between rainfall and russet occurrence by artificial treatment of high humidity. Under high relative humidity condition, stomatal resistance decreased and average fruit weight was higher since the increased net photosynthesis rate accumulation accelerated fruit growth. The russet occurrence began on July 25, when the growth speed of fruit weight and fruit surface is the most fast. Russet occurrence rate was higher in high relative humidity condition because the fruit growth was accelerated. Since the fruit calcium concentration change is extreme in late July, it is assumed that the deceased calcium content is related to the occurrence of russet in 'Whangkeumbae' pear, When the high relative humidity condition is maintained after rainfall, the amount of net photosynthesis rate increase and fruit growth is accelerated. Therefore, the unbalance in the amounts of transferred photosynthesis assimilation product, water and mineral elements would be one of the reasons for the russet occurrence in 'Whangkeumbae' pear.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.328-333
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• 2006

This study was conducted to find the characteristics of photosynthesis, leaf and fruit by crown layers in Rubus coreanus Miq. Light compensation points were shown PPFD 33, 20 and $5{\mu}mol\;m^{-2}\;S^{-1}$ at upper, middle and lower layer, respectively. Light saturation points were appeared PPFD 1000, 500 and 200 and their net photosynthesis rate were 8.52, 5.25 and $3.60{\mu}mol\;CO_2\;m^{-2}S^{-1}$ at upper, middle and lower layer, respectively. Uiryeong 7 which was viny type showed higher net photosynthetic rate than others at upper layer. Songgye 6 which was upright type showed lower net photosynthetic rate than others at lower layer. Chlorophyll contents of middle layer had the highest value in the all layers and upper layer showed the lowest value. Most characteristics of leaf morphology were showed that middle and lower layer had higher value than upper layer. That trend was contrary to characteristics of photosynthesis by crown layers. However, dry weight per leaf area and most characteristics of fruit had the highest value at upper layer and that was similar to characteristics of photosynthesis by crown layers. Also, sugar contents of fruit showed the highest value at middle layer.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.47-52
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• 2006

This studies were carried out in summer season to increase high temperature tolerance using hydrogen peroxide treatments on cucumber in greenhouse. The water stress of cucumber in greenhouse by the hydrogen peroxide treatments showed as control>250 mM>500 mM treatments in order. The photosynthesis rate of cucumber at $30^{\circ}C$ did not show difference with each hydrogen peroxide treatment in temperature controlled greenhouse. However, the photosynthesis rate of cucumber in the control and hydrogen peroxide treatments at $40^{\circ}C$ was significantly different. The photosynthesis rate of cucumber in combined treatment with 1,000 $mg{\cdot}L^{-1}\;CO_2$ supply and hydrogen peroxide was also higher than control, however, there was no different of photosynthesis in 250 mM and 500 mM treatment. The value of $F_v/F_m$ and $F_m/F_o$ of chlorophyll fluorescent in 500 mM hydrogen peroxide treatment at $40^{\circ}C$ was highest. Also the activity of POD, the antioxidant enzyme, was higher with high hydrogen peroxide concentration than the other treatments. The high temperature limits for growth were $43^{\circ}C$ in the control, $44^{\circ}C$ in the 250 mM and $46^{\circ}C$ in the 500 mM according to analyze chlorophyll fluorescent $F_o$. The high temperature tolerance in cucumber increased approximately $3^{\circ}C$ by the hydrogen peroxide treatments under this experiment conditions.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.169-169
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• 2022

Over the past 100 years, the global average temperature has risen by 0.75 ℃. The Korean Peninsula has risen by 1.8 ℃, more than twice the global average. According to the RCP 8.5 scenario, the CO₂ concentration in 2100 will be 940 ppm, about twice as high as current. The National Institute of Crop Science(NICS) is using the SPAR (Soil-Plant Atmosphere Research) facility that can precisely control the environment, such as temperature, humidity, and CO₂. A Python-based colony photosynthesis algorithm has been developed, and the carbon and nitrogen absorption rate of rice is evaluated by setting climate change conditions. In this experiment, Oryza Sativa cv. Shindongjin were planted at the SPAR facility on June 10 and cultivated according to the standard cultivation method. The temperature and CO₂ settings are high temperature and high CO₂ (current temperature+4.7℃ temperature+4.7℃·CO₂ 800ppm), high temperature single condition (current temperature+4.7℃·CO₂ 400ppm) according to the RCP8.5 scenario, Current climate is set as (current temperature·CO₂400ppm). For colony photosynthesis measurement, a LI-820 CO₂ sensor was installed in each chamber for setting the CO₂ concentration and for measuring photosynthesis, respectively. The colony photosynthetic rate in the booting stage was greatest in a high temperature and CO₂ environment, and the higher the nitrogen fertilization level, the higher the colony photosynthetic rate tends to be. The amount of photosynthesis tended to decrease under high temperature. In the high temperature and high CO₂ environment, seed yields, the number of an ear, and 1000 seed weights tended to decrease compared to the current climate. The number of an ear also decreased under the high temperature. But yield tended to increase a little bit under the high temperature and high CO₂ condition than under the high temperature. In addition, In addition to this study, it seems necessary to comprehensively consider the relationship between colony photosynthetic ability, metabolite reaction, and rice yield according to climate change.

• The Korean Journal of Ecology
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• v.1 no.1
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• pp.3-10
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• 1977

The sigmoiod kinetics of mass-action in a biosystem have been studied by theoretical bases on the carrier hypothesis of influx and efflux of substrates. The sigmoid kinetic equations of assimilation and dissimilation rates indicate that each trophicfactor and each bio-factor behave according to the sigmoid kinetic equation and the bell shape case, and all of them are multiplicative. The general sigmoid kinetics of mass-action is given by the equation (30) which is determined by the total of the equation (28) of the assimilation rate and the equation (29) of the dissimilation rate. The sigmoid kinetic model of photosynthesis has been derived from the general equation of the sigmoid kinetics of mass-action.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.124-132
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• 2001

This study was conducted to reveal the relationship between physiological characteristics and growth by family for open-pollinated progeny stand of Korean white pine in Gapyung site. Average growth performance of total 25 families for 18 years old progeny stand in this study site showed 5.9m in mean height, 8.9cm in mean DBH, $12.0m^2$ in basal area per hectare and $46.5m^3$ in volume per hectare, respectively. By the analysis result of growth performance for all 25 families, family No. 20 showed the most excellent growth and middle in family No. 10. On the other hand, family No. 3 represented the worst growth among the 25 families. The change of seasonal photosynthesis rate by increasing luminous intensity was the same tendency as the growth pattern of all 25 families and showed the same results in all four seasons. In the seasonal analysis, the photosynthesis rate was increased as the season has changed from winter to summer. Chlorophyll contents was also increased from winter to summer. Especially, family No. 20 which is the best in growth performance has more chlorophyll contents than the others. In addition, family No. 20 was also better than other families in the weight of assimilation tissue(g), length of needle(cm), width of needle(cm), and number of Stoma. However, in water utilization rate, family No. 3 which is the worst in the growth performance showed the best result that is reverse tendency compared with the photosynthesis rate. The changes of water utilization rate represented to be increased as the season has changed from winter to summer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.237-244
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• 1994

To elucidate the physiological characteristics of 2 japonica type and 2 tongil type of rice cultivars, photosynthesis, respiration and diurnal changes of photosynthesis rate had been investigated 6 times at each growing stage. The ratios of photosynthetic part of tongil types were higher than those of japonica types at tillering stage. The highest photosynthetic activity was measured on August 1, before heading in each growing stage, and efficiency of photosynthesis showed its the highest on July 25. Diurnal photosynthetic curve at heading stage reached the peak at 11-12 AM, but after 2 weeks from heading stage, the peak apperred at 1-2 PM. Conversion of respiration into photosynthesis for $CO_2$ fixation started 30~60 minutes later than the standard sunrise time and reconversion for carborhdrate accmulation began 50~60 minutes earlier than the standard sunset time. Photosynthesis showed positive correlation with chlorophyll content and root activity. Harvest index of tongil type cultivars were significantly higher than those of japonica type cultivars.