• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.255-259
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• 1995

Improvement in potential Crop yield could be achieved through either the improve-ment of source potential or sink capacity, but preferably both simultaneously. The field experiment was performed to evaluate the genotypic difference in partitioning of dry matter into each plant part in response to photosynthetic manipulation as well as to assess whether the soybean yield is source or sink-limited. Four soybean genotypes, which were 'Baekunkong', 'Suwon 168', and two local soy-beans with black seed coat(hereafter referred to as the 'black soybean', 'Kangleungjarae' and 'Keumleungjarae', were grown in four different environments in which one or two layers of shading net during grain filling and two different planting densities(55,000 and 110,000 plants $ha^{-1}$) were applied to manipulate photosynthesis. Significant effects of genotype (G), photosynthetic manipulation(P), and$G^p$P were shown in top and grain dry weight. Relative grain to top dry weight was the lowest in soybean plants grown at 110,000 plants$ha^{-1}$and covered with two layers of shading net during grain filling, Evaluation of dynamic changes in shoot harvest index in response to photosynthetic manipulation treatments revealed that sink was more limited in local black soybeans than Suwon 168 and Baekunkong, indicating that the availability of photosynthate during grain filling did not limit the grain yield in local black soybeans when compared to Baekunkong and Suwon 168.oybeans when compared to Baekunkong and Suwon 168.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.223-228
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• 1985

Photosynthetic inhibition to temperature were conducted with ginseng(4 year old) and tobacco(var. Bulgaria). The plants were kept under various temperature conditions from 1$0^{\circ}C$ to 4$0^{\circ}C$ and 440$\mu$E/$m^2$/sec for 3 and 6hrs, and net $CO_2$ uptake were measured after 2hrs at $25^{\circ}C$. Photosynthetic optimal leaf temperature of ginseng was 21$^{\circ}C$ and tobacco was $25^{\circ}C$. Stomatal resistance and mesophyll resistance increased at high temperature. Especially, stomatal resistance seemed to have a significant role in determining the temperature responses of photosynthesis. In tobacco photosynthetic capacity was not changed by temperature treatment for 3hrs. However, 6hrs exposure reduced 8% of net photosynthesis at 4$0^{\circ}C$ and 12% at 1$0^{\circ}C$. Ginseng plants exposed for 6hrs at 4$0^{\circ}C$ lost photosynthetic capacity by 83%. Temperature responses of ginseng were very sensitive at above-optimum temperature resulting greater thermal inhibition other than photoinhibition.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.203-213
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• 2024

In this study, we investigated the growth and physiological responses of Iris laevigata Fisch. to shading treatments in order to suggest optimal light conditions for ex-situ conservation of the northern lineage plants. For this purpose, a control plant receiving full sunlight and different shading treatments (50%, 75%, 95%) were installed, and leaf mass per area, chlorophyll content and fluorescence response, and photosynthetic characteristics were investigated. I. laevigata developed leaves with higher photosynthetic efficiency to adapt to lower light intensity as shading levels increased. Chlorophyll content increased with increasing shading levels, and leaf mass per area decreased with increasing leaf area. The chlorophyll fluorescence responses Fv/Fm and NPQ did not change with shading, and the activity of the carbon fixation system did not differ between treatments. I. laevigata exhibited a light-saturation point equivalent to that of sun plants and maintained photosynthetic capacity similar to that of controls up to 75% shading. The apparent quantum yield of I. laevigata decreased significantly at 95% shading, indicating adaptation to lower light conditions. It seems that the photosynthetic capacity of I. laevigata decreases when grown under 95% shading level compared to full sunlight, and it is judged that the longer the light is restricted by continuous shading, the more unfavorable the growth will be.

• Animal cells and systems
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• v.10 no.3
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• pp.125-130
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• 2006

We have examined the bioaccumulation patterns and the ecophysiological responses (photosynthetic pigment and total antioxidative capacity) of Monochoria korsakowi exposed to various cadmium concentrations, one of major environmental pollutants. Cadmium ion contents in M. korsakowi increased significantly with higher cadmium concentration, and most of the accumulated cadmium was found in the root parts. Biomass of each part decreased with higher cadmium concentration. As cadmium treatment concentration was increased, chlorophyll a content was decreased, whereas chlorophyll b content was increased. However, the variations of total chlorophyll and carotenoid contents were not evident. Total antioxidative capacity in the leaves of cadmium treated M. korsakowi increased greatly with higher cadmium concentration. We considered these results as indicative of the ability of M. Korsakowi plants to take up cadmium from wetlands.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.1
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• pp.22-28
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• 2014

This study was conducted to investigate the photosynthetic characters of Populus alba${\times}$glandulosa cuttings in response to elevated $CO_2$ concentration and air temperature for selecting tree species adaptive to climate change. The cuttings were grown in environment controlled growth chambers with two combinations of $CO_2$ concentration and air temperature conditions: (i) $22^{\circ}C$ + $CO_2$ 380 ${\mu}mol$ $mol^{-1}$ (control) and (ii) $27^{\circ}C$ + $CO_2$ 770 ${\mu}mol$ $mol^{-1}$ (elevated) for almost three months. The cuttings under the elevated treatment showed reduced tree height and photosynthetic pigment contents such as chlorophyll and carotenoid. In particular, the elevated treatment resulted in a marked reduction in the chlorophyll a closely associated with $CO_2$ fixative reaction system. Different levels of reduction in photosynthetic characters were found under the elevated treatment. A decrease was noted in photochemical reaction system parameters: net apparent quantum yield (7%) and photosynthetic electron transport rate (14%). Moreover, a significant reduction was obvious in $CO_2$ fixative reaction system parameters: carboxylation efficiency (52%) and ribulose-1,5-bisphosphate(RuBP) regeneration rate (24%). These results suggest that the low level of photosynthetic capacity may be attributed to the decreased $CO_2$ fixative reaction system rather than photochemical reaction system.

• 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.

• Proceedings of the Korean Society of Potoscience Conference
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• 2002.06a
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• pp.60-60
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• 2002

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.182.2-182
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.05a
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• pp.138-139
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• 2001

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.2
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• pp.79-89
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• 2012

This study was conducted to investigate the chlorophyll contents, photosynthetic characteristics, chlorophyll fluorescence, and growth performance of Parasenecio firmus under changing light environment. Parasenecio firmus was grown under non-treated (full sunlight) and three different shading conditions (88~93%, 65~75% and 45%~55% of full sunlight) for the experiment. Total chlorophyll content, photochemical efficiency (Fv/Fm), T/R ratio, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) were increased with increasing shading level, but decreased dark respiration. Therefore, light absorption and light utilization efficiency were improved under the low intensity light. Plants under 65~75% of full sunlight had best maximum photosynthetic rate and net apparent quantum yield in May. On the other hand, the non-treated plants had lower maximum photosynthetic rate, photochemical efficiency, and chlorophyll content than the treated ones. Parasenecio firmus considered to be a sciophyte, is fairly sensitive to high intensity light. If 88-93% of full sunlight lasts for a long period, photosynthetic capacity will be sharply decreased, though limiting light. These results suggest that growth of Parasenecio firmus adapted to 65~75% of full sunlight.