• Journal of Life Science
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• v.8 no.5
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• pp.557-562
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• 1998

This study was conducted to investigate the influence of soil moisture on the photosynthetic rate, transpiration rate, stomatal conductance, leaf water content and its any correlation in soybean. Followings were achieved as a conclusion. At the soil moisture was moved from drought condition to saturation condition, the photosynthetic rate, transpiration rate, stomatal conductance and leaf water content were gradually increased on the period of re-watering treatment. The recovery of photosynthetic rate was faster than others. There were positive correlation with the photosynthetic rate and leaf water content, the stomatal conductance and leaf water content, the photosynthetic rate and stomatal conductance respectively, but the correlation coefficient of photosynthetic rate and leaf water content was high.

• Journal of Environmental Science International
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• v.26 no.10
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• pp.1147-1153
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• 2017

To maintain a rich biological diversity is important to develop for biomaterial resources such as Korean evergreen broad-leaved tree species, the distribution of which is restricted to the southern part of Korean peninsula. We assessed photosynthetic characteristics of Quercus acuta and Castanopsis sieboldii, the representative evergreen broad-leaved trees in Korea, in order to establish a basis for conservation strategy related to distributional change in evergreen broad-leaved tree species according to climate change. Photosynthetic characteristics were evaluated in the sun and shade leaves of the two species. Sun leaves in both species revealed higher light compensation point and maximum photosynthetic rate compared to the shade leaves. In addition, photosynthetic rate was higher in Q. acuta than C. sieboldii, which was supported by a higher leaf nitrogen content and leaf mass per area. Water use efficiency was also higher in Q. acuta as compared to that in C. sieboldii. Similar photosynthetic rate, however, was shown in photosynthetic response to $CO_2$ concentration in the intercellular space. These results suggest that both species could respond differently to the changing environmental factors including climate change, suggesting the possibility of distributional changes resulting from a differential growth rate.

• Journal of Life Science
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• v.20 no.7
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• pp.1127-1133
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• 2010

The total photosynthetic rate in leaf mustard lines, which was calculated as the sum of the photosynthetic rate and the respiration rate, was not significantly different from their photosynthetic rate. Plant height, standing of rosetteness, showed a similar change to its specific leaf area (SLA). With increasing the plant height, leaf density increased and leaf color was lighter. It was found that shoot dry weight of leaf mustard was more affected by respiration. Also, it was hypothesized that respiration occurred not only in the leaf but also the stem. It was found that mustard lines whose leaf density was low showed a higher shoot growth. From this result, it was concluded that selection of a leaf mustard line with a larger SLA and lower leaf thickness could be effective in increasing photosynthetic rate.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.20-26
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• 1995

This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.

• The Korean Journal of Ecology
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• v.24 no.4
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• pp.223-226
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• 2001

The leaf water relations and photosynthetic rate during acute soil drying were compared in potgrown grapevine cultivars, Vitis vinifera cv. Chardonnay and V. vinifera cv. Riesling. Leaf water potential in Riesling decreased significantly from day 2 after water had been withheld, while in Chardonnay leaf water potential for the water-stressed plants was almost identical with that in well watered plants during the first 4 days. Higher stomatal conductance and photosynthetic rate in Chardonnay than Riesling were observed until day 3 after withholding water. Photosynthetic rate in water-stressed Chardonnay was not different from that in control plants until day 3 after withholding water, while that in water-stressed Riesling was reduced markedly from day 2. In Riesling, osmotic potential at turgor loss point was not changed irrespective of watering conditions. However, in Chardonnay osmotic potential at turgor loss point decreased more in the water stressed conditions than in well watered conditions. The osmotic adjustment in Chardonnay under water stress conditions must contribute to the maintenance of higher stomatal conductance and photosynthetic rate than those in Riesling for a significant period of the drying process. Though difference in stomatal conductance between the two cultivars was shown in the process of soil drying, stomatal conductance of both cultivars responded to vapor pressure difference between leaf and ambient air, rather than soil water status and leaf water potential.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.146-152
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• 2013

The photosynthetic rates according to leaf positions in tomato plants were investigated in relation to leaf age and flowering rate. In the experiment investigating the diurnal change of photosynthetic rates, three leaves below the 4th cluster was checked every hour from 2 hours before sunrise and 3 hours after sunset. It was checked twice with the replication of 3 plants. The photosynthetic rate increased sharply for 1 hour right after sunrise and remained steady until 2 hours before sunset. This trend can be applied to determine the irrigation schedule. In the experiment investigating the photosynthetic rates according to leaf positions, it three leaves below each clusters from 1st to 4th cluster were checked. Flowering rate was also investigated. The photosynthetic rates showed a decreasing tendency steadily after flowers bloomed fully, regardless of the leaf position. It seems to be because the leaves below the cluster with fully-bloom flowers lost their activities. This result suggests the flowering rate or the position of flower has deep relation with the photosynthetic rates of the concerned leaves. From the results the leaves under flowering cluster may be the good part to investigate the photosynthetic rate to evaluate the crop's activity, even the photosynthetic rates are different according to the position of clusters.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.120-124
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• 2021

In order to understand the vegetative role of Glycine soja, we studied the basic physiological characteristics between Glycine soja and Glycine max. For this study, the light intensity (μmol m^-2 s^-1) on leaf surface, leaf temperature (℃), transpiration rate (mmol m^-2 s^-1), photosynthetic rate (μmol m^-2 s^-1), substomatal CO₂ partial pressure (vpm) of Glycine soja and Glycine max were measured, and the quantum yield, photosynthesis rate per substomatal CO₂ partial pressure were calculated. In the results of simple regression analysis, the increasing quantum yield decreases leaf temperature both of Glycine soja and Glycine max and the increasing leaf temperature decreases transpiration rate in case of Glycine soja. However, in case of Glycine max, the increasing leaf temperature decreases substomatal CO₂ partial pressure, photosynthetic rate, and photosynthetic rate per substomatal CO₂ partial pressure as well as transpiration rate. Also, increasing transpiration rate increases substomatal CO₂ partial pressure while decreases photosynthetic rate per substomatal CO₂ partial pressure. Thus, Glycine soja is relatively more easily adaptable to severe environments with low soil nutrients and high light levels. Compared to Glycine max susceptible to water loss due to a water-poor terrestrial habitat, the physiological traits of Glycine soja has a high average transpiration rate and are less susceptible to water loss will act as a factor that limits the habitat according to soil moisture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.313-319
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• 1992

To investigate effects of water stress on apparent photosynthetic, transpiration rates, leaf orientation, yield and its related traits, four soybean varieties were planted on the Wagner pots in a plastic house covered with polyethylene film. As the light intensity and leaf temperature in a day increased, the movement of central leaflet in the second leaf of main stem occurred earlier than that of the lateral leaflet. The apparent photosynthetic rate of the central leaflet was higher than that of the lateral leaflet, but light intercept and leaf temperature of lateral leaflet were higher than those of the central leaflet. The apparent photosynthetic rate had highly positive correlation with the photon flux density, stomatal conductance and temperature, respectively. The photon flux density, stomatal conductance, transpiration and photosynthetic rates in the control were significantly higher than those in the water stress plot. The yield and its related traits in the water stress plot became decreased significantly in comparison with the control.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.45-49
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• 2003

Foliar treatment with different concentrations of potassium chloride (KCl) to mulberry plants resulted in higher level of total chlorophyll, total sugars, soluble protein, in vivo nitrate reductase activity (NRA), net photosynthetic rate (NPR), pWUE and leaf yield. Optimal concentration was found to be 10.0 mM KCl with limited irrigation provided in the mulberry plantation planted in 90 ${times}$ 90 cm spacing. The deleterious effect of soil moisture stress condition has been found to be overcome by KCl foliar spray twice at 15 days interval. Regression and correlation coefficients were analyzed, and a strong positive correlation was found between chlorophyll and total sugars, soluble protein and in vivo nitrate reductase activity, leaf dry weight and net photosynthetic rate and pWUE and net photosynthetic rate.

• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.133-137
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• 2006

Evaluation of physiological performance of trehalose-producing transgenic rice line was conducted to investigate drought tolerance at early growth stage. Under artificially induced drought condition of 8% polyethylene glycol 6000, this transgenic rice line had leaf photosynthetic rate of 11.08 uml CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 8.38 mmol $H_2O$ $m^{-2}s^{-1}$ and leaf water potential of -1.12 MPa after 96 hours of treatment. Nakdongbyeo, the parent of this tyansgenic rice line, had photosynthetic rate of 15.42 $\mu$mol CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 8,04 mmol $H_2O$ $m^{-2}s^{-1}$ and leaf water potential of -0.88 MPa. The other variety used in this experiment for comparison, IR 72, showed higher values than both tyansgenic rice line and variety Nakdonbyeo on all three parameters; leaf photosynthetic rate of 20.61 $\mu$mol CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 12.88 mmol $H_2O$ $m^{-2}s^{-1}$, and leaf water potential of -0.82 MPa. So this transgenic rice line did not show superior performance in leaf transpiration rate, leaf photosynthetic rate and leaf water potential compared to variety Nakdongbyeo. This result along with visual observation on leaf rolling and drying during the experimental period indicated poor physiological performance of this transgenic rice line. Further studies on metabolic status of stress-induced trehalose, along with study on physiological response of this transgenic rice line during drought stress would shed more light on overall physiological performance of this transgenic rice line.