• ALGAE
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• v.17 no.2
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• pp.83-87
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• 2002

Photosynthetic parameters of Scendesmus quadricauda, such as the maximum photosynthetic rate ($P_{max}$), photosynthetic efficiency (α) and the initial saturation intensity of irradiance for photosynthesis ($I_K$) were obtained using photosynthesis-irradiance (P-I) curve in a phosphorus-limited chemostat. S. quadricauda exhibitied no photoinhibition until at 200 μmol·$m^{-2}$ . $P_{max}$ (r=0.963, P=0.002) and $I_K$(r=0.904, P=0.013) showed linear relationships with growth rate. Chlorophyll-α concentration and cell dry weight decreased at higher growth rates, ut chlorophyll-α content per cell dry weight increased. The increase in photosynthetic rates at higher growth rates was due to the increase of $P_{max}$ and $I_K$ which was caused mainly by the increase in the absolute amount of chlorophyll-α rather than the increased photosynthetic efficiency of individual chlorphyll-α. The α did not show a significant relationship with growth rate (r=0.714, P=0.111). The cell quota of carbon (r=0.554, P=0.254) was not correlated with growth rate, but cell quota of nitrogen (r=0.818, P=0.047) and phosphorus (r=0.855, P=0.030) exhibited linear correlations with growth rate.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.55-60
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• 2007

This study was conducted to find characteristics of photosynthesis for dwarf and street tree cultivars of Hibiscus syriacus L. Characteristics of growth and flowering on some cultivars were investigated. The photosynthetic capacity for the cultivars was also measured. Bulsae showed the best height increase; Soyang represented the lowest growth. Baektanshim ${\times}$ Kyungbuk1 had the largest number of branches and leaves. Sundeok and Bulsae were the best in terms of height and width of flower, Soyang showed the smallest flowers. According to the analysis of chlorophyll content (chlorophyll a, b, total) for the cultivars, there was little difference between Sundeok and Bulsae. Based on light response curves for cultivars, it was found that Baektanshim ${\times}$ Kyungbuk1 and Soyang had lower light compensation and light saturation points than Bulsae and Sundeok. Cultivars Baektanshim ${\times}$ Kyungbuk1 and Soyang were also low in dark respiration, photosynthetic capacity, and net apparent quantum yield. In conclusion, it is recommended that cultivars Baektanshim ${\times}$ Kyungbuk1 and Soyang might be used as a dwarf type due to photosynthetic capacity.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.85-102
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• 2023

Background: Ecophysiological characteristics of Rosa rugosa were analyzed under different environmental factors from May to October 2022. Photosynthesis, chlorophyll fluorescence, chlorophyll content, leaf water content (LWC), osmolality, carbohydrate content, and total ion content were measured to compare the physiological characteristics of R. rugosa at two study sites (i.e., in large pots and in the Goraebul coastal sand dune area). Results: When R. rugosa was exposed to high temperatures, photosynthetic parameters including net photosynthetic rate (P_N) and stomatal conductance (g_s) in both experiment areas declined. In addition, severe photoinhibition occurs when R. rugosa is continuously exposed to high photosynthetically active radiation (PAR), and because of this, relatively low Y(II) (i.e., the quantum yield of photochemical energy conversion in photosystem II [PSII]) and high Y(NO) (i.e., the quantum yield of non-regulated, non-photochemical energy loss in PSII) in the R. rugosa of the pot were observed. As the high Y(NPQ) (i.e., the quantum yield of regulated non-photochemical energy loss in PSII) of R. rugosa in the coastal sand dune, they dissipated the excessed photon energy through the non-photochemical quenching (NPQ) mechanism when they were exposed to relatively low PAR and low temperature. Rosa rugosa in the coastal sand dune has higher chlorophyll a and carotenoid content. The high chlorophyll a + b and low chlorophyll a/b ratios seemed to optimize light absorption in response to low PAR. High carotenoid content played an important role in NPQ. As a part of the osmotic regulation in response to low LWCs, R. rugosa exposed to high temperatures and continuously high PAR used soluble carbohydrates and ions to maintain high osmolality. Conclusions: We found that F_v/F_m was lower in the potted plants than in the coastal sand dune plants, indicating the vulnerability of R. rugosa to high temperatures and PAR levels. We expect that the suitable habitat range for R. rugosa will shrink and move to north under climate change conditions.

• The Korean Journal of Food & Health Convergence
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• v.6 no.1
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• pp.17-20
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• 2020

Wheat is the most abundant crop in the world, accounting for one third of the world's population diet. In Ukraine, wheat is in fact, in addition to its nutritional value, a national symbol of the state. Therefore, the main thesis on the development of modern plant growing in Ukraine is the reduction of costs and the introduction of innovative technologies. The quality of grain and seed depends on many factors, namely: agro-climatic conditions, sowing condition of the seed material, quality characteristics of the soil, yielding properties of seeds, pre-sowing seed treatment. etc. For this purpose, the photosynthesis and intensity of photosynthesis need to be limited to the width of the leaf and the height of the leaves by a smaller cut of the stem. It is extremely important to ensure that the head and side pagons of wheat are in good condition. All parameters are often secured by the technology of grain preparation before delivery. Prior to this technology, it is possible to introduce processing of the material in the form for the development of the material. This article presents the effectiveness of the use of infrared irradiation for the pre-sowing treatment of winter wheat seeds in Sekobra Research, Germany.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.17-22
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• 2020

This study was conducted to find out the optimum composition of nursery soil for raising seedling of Zelkova serrata. The treatments were regulated with the three different soil types : full peat moss(PM 100%), peat moss + perlite + vermiculite(1:1:1), peat moss + perlite + vermiculite(1:2:1). The full peat moss(PM 100%) showed the highest photosynthetic activity such as maximum photosynthesis rate(PN max), water use efficiency(WUE), Fv/Fm, PIabs and SPAD value. And also, full peat moss(PM 100%) showed relatively better growth performances. As a result of surveying the whole experiment, full peat moss(PM 100%) soil increases growth performances and enhances overall quality.

• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.133-134
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• 2007

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.183-184
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• 2010

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.229-230
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• 2010

• Animal cells and systems
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• v.4 no.4
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• pp.325-328
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• 2000

Parthenin was extracted from Parthenium hysterophorus L. leaves growing in northern part of India, and its effect was tested on the seed germination parameters and other related characteristics of Ageratum conyzoides L. weed. Parthenin proved phytotoxic to A. conyzoides as most of the studied parameters were inhibited. It may lead to a possible biological eradication of the A. cpnyzoides weed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.145-152
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• 2013

This study aimed to investigate the growth and physiological characters of Liriodendron tulipifera seedlings in responses to two different levels of elevated air temperature and $CO_2$ concentration. The seedlings were grown in environment-controlled growth chambers with two combinations of air temperature and $CO_2$ conditions: (1) $22^{\circ}C$ + ambient $CO_2$ $380{\mu}mol\;mol^{-1}$ and (2) $27^{\circ}C$ + $770{\mu}mol\;mol^{-1}$. Physiological characters such as growth, photosynthesis, and water use efficiency, were monitored for 85 days. The seedlings under the elevated treatment showed a greater amount of growth in tree height, compared with those under the control. Regarding the characteristics of assimilatory organs, the elevated treatment resulted in a greater amount of total leaf area, leaf unfolding, and dry weight per leaf area. No significant differences were found in photosynthesis capacity between the two treatments. The increase in water use efficiency with increased intercellular $CO_2$ partial pressure appeared overall lower in the seedling under the elevated treatment, compared with those under the control. The total leaf area of the seedlings under the elevated treatment was larger than that under the control, indicating a higher amount of photosynthesis. In addition, an increase of root growth was noted under the elevated treatment. A resistance mechanism of water stress may be attributed to a higher amount of organ growth as well as the tree height under the elevated treatment than the control.