• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.279-283
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• 2004

This experiment was carried out at paddy field (commercial silty loam soil) in the southwestern Korea. Pungsannamulkong, a determinate growth habit, was a relatively high yielding and late maturing cultivar, and Han­namkong, a semi determinate growth habit, was a relatively low yielding and early maturing cultivar. Seeds were sowed at two plants and with a planting density of $70{\times}10cm$ on May 26, 2003. Fertilizer was applied prior to planting at a rate of 3.0-3.0-3.4g $(N-P_2O_5-K_2O)\;per\;m^2$ by all basal fertilizations. Experimental design was a randomized complete block with three replications. Seed yield was higher in Pungsannamulkong by 362g per $m^2$ than in Hannamkong of 260g per $m^2$ Also, the number of pod, number of seed, and number of seed per pod were greater in Pungsannamulkong than in Hannamkong. The number of leaves per $m^2$ showed similar with two soybean cultivars up to August 24 but thereafter it decreased in Hannamkong. The leaf area up to August 4 increased in Hannamkong higher than in Pungsannamulkong, but after that time, Pungsannamulkong had greater leaf area than Hannamkong. The shoot and leaf dry matter of two soybean cultivars from June 23 to August 4 were similar but thereafter, Pungsannamulkong had a significantly greater than Hannamkong. Crop growth rate (CGR), relative growth rate (RGR) and net assimilate rate (NAR) for Punsannamulkong were relatively higher than Hannamkong but leaf area ratio (LAR) and specific leaf weight (SLW) showed higher in Hannamkong. Most of leaves distributed in the ranges of 80-90cm and 60-70cm from the soil surface in Punsannamulkong and Hannamkong, respectively. Pods of Punsannamulkong ranged 10-80cm from the soil surface and most of pods were distributed at 40-50cm. Photosynthetic rate at the flowering stage showed a significant difference between cultivars in the upper most leaf position. There was no significant difference of the photosynthetic rate at $7^{tn}$ leaf at the flowering stage, and the uppermost and 7th leaf position at the seed development stage between two soybean cultivars.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.275-284
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• 2022

Changes in air temperature, CO₂ concentration and precipitation due to climate change are expected to have a significant impact on soybean productivity. This study was conducted to evaluate the climate change impact on growth and development of determinate soybean cultivar in the southern parts of Korea. The high temperature during vegetative period, which does not accompany the increase of CO₂ concentration, increased the canopy photosynthetic rate in soybean, but after flowering, the high temperature above the optimal ranges interrupts the photosynthetic metabolism. In yield and yield components, high temperature reduced both the pod and seed number and single seed weight, resulting in a reduction of total seed yield. On the other hand, the increase in CO₂ concentration dramatically increased the canopy photosynthetic rate over the whole growth period. In addition, high CO₂ concentration increased the number of pods and seeds, which had a positive effect on total seed yield. Under concurrent elevation of air temperature and CO₂ concentration, canopy photosynthesis increased significantly, but enhanced canopy photosynthesis did not lead to an increase in soybean seed yield. The increase in biomass and branch by enhanced canopy photosynthesis seems to be attributed to an increase in the total number of pods and seeds per plant, which compensates for the negative effects of high temperature on pod development. However, Single seed weight tended to decrease rapidly by high temperature, regardless of CO₂ concentration level. Elevated CO₂ concentration did not compensate for the poor distribution of assimilations from source to sink caused by high temperature. These results show that the damage of future soybean yield and quality is closely related to high temperature stress during seed filling period.

• 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.55 no.2
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• pp.111-118
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• 2010

Stress due to excess water is one of the most limiting factor for soybeans to high yield under wet climates. This study aimed to identify the photosynthetic responses of soybeans to waterlogged growing condition with 5 soybean varieties by waterlogging for 10 days at V5 and R2 stage, respectively. Chlorophyll fluorescence decreased more rapidly at R2 stage waterlogging than at V5 stage waterlogging in all soybean tested varieties. The degree of recovery was much more in Pungsannamulkong and Muhankong( 95～97% of control) than in Jangyeobkong and Myungjunamulkong at 5 days after waterlogging. Photosynthetic rate, transpiration and stomatal conductance were also increased more rapidly in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong after waterlogging irrespective of waterlogging stages. As the result of multiple regression analysis in order to identify the effects of stomatal conductance and transpiration to the photosynthetic rate, the R2 value of stomatal conductance in control and waterlogging treatment was 0.7293 and 0.7582, respectively. If the transpiration, another dependent variable, was added to the regression formula, there was not so big difference in the variation of photosynthetic rate. This result means that if just one factor of them(the stomatal conductance and transpiration) be measured in the case of waterlogged condition, the changes of photosynthetic rate can be estimated.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.643-648
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• 2002

For wastewater treatment and utilization of the biomass, a photosynthetic bacterium was isolated based on its cell growth rate, cell mass, and assimilating ability of organic acids. The isolate was a Gram-negative rod-shaped bacterium that contained a single polar flagellum and formed a lamellar intracytoplasmic membrane (ICM) system, including bacteriochlorophyll $\alpha$. The major isoprenoid quinone component was identified as ubiquinone Q-10, and the fatty acid composition was characterized as to contain relatively large amount of C-16:0 (18.74%) and C-18:1 (59.23%). Based on its morphology, phototrophic properties, quinone component, and fatty acid composition, the isolate appeared to be closely related to the Rhodopseudomonas subgroup of purple nonsulfur bacteria. A phylogenetic analysis of the isolate using its 16S rRNA gene sequence data also supported the phenotypic findings, and classified the isolate closely related to Rhodopseudomonas palustris. Accordingly, the nomenclature of the isolate was proposed as Rhodopseudomonas palustris KUGB306. A bench-scale photosynthetic bacteria (PSB) reactor using the isolate was designed and operated for the treatment of soybean curd wastewater.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.320-324
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• 2007

To characterize flooding-affected anatomical morphology changes in soybean, flooding-tolerant cv Pung-sannamulkong (PSNK) and flooding-sensitive cv. Sobaek-namulkong (SBNK) at 5 trifoliate leaf stage were exposed to flooding by maintaining tap water 2 cm above soil surface for 9 days and resultant microscopic anatomical changes in leaf and hypocotyl cross-sections along with chlorophyll content and photosynthetic rate changes were compared. Flooding-sensitive SBNK exhibited more significant decrement in chlorophyll content, photosynthetic rate, number of palisade parenchyma, and leaf dry matter compared to cv. PSNK. Flooding decreased fineness of palisade parenchyma, while inducing wider xylem vessel, especially in PSNK. The aerenchyma formation in hypocotyls under flooding could be observed only in flooding-resistant PSNK. All these anatomical changes seems to be related with higher physiolocial activity and resultant resistance against flooding in PSNK compared to flood-sensitive PSNK.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.1-8
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• 2006

The differential response of soybean cultivars with or without sulfur (S) application was observed under fold conditions. Plant biomass decreased by sulfur deficiency but the reduction was less in Bragg variety about 26 % relative to the control than other ones over 45%, probably due to less reduction in loaves and pods. The photosynthetic rate of Bragg cultivar was also unaffected by the absence of sulfur application while it depressed in other lines. Soybean cultivars were compared in terms of storage protein, protein quality and biomass production by application of sulfur nutrition. The storage protein concentration tended to decrease without sulfur application in all the cultivars, however the differential response of protein quality only by 11S/7S ratio to sulfur nutrition status was observed: For instance, Bragg cultivar had higher biomass and protein production but protein quality decreased at sulfur deficiency. On the other hand, biomass and protein production in other cultivars remained louver at sulfur deficiency but protein quality differed genetically in spite of sulfur nutrition status. These results suggest that the response of soybean to sulfur nutrition is controlled by genotypic difference and sulfur supply status.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.11-15
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• 2005

This experiment was conducted to investigate the changes of growth and maturity and to clarify the function of supernodulating characters, excessive nodules and high biological nitrogen fixation rate (BNF), on maturity in response to different planting time in supernodulating soybean mutants. Two supernodulating soybean mutants, Sakukei4 and SS2-2, and their parent cultivars, Enrei and Shinpaldalkong2, were planted on May 24 and June 15, 2004. The degrees of the shortening of growth days by the planting time delay were 18 to 22 days in four cultivar, and there were no significant differences among the cultivars. However, four cultivars showed the different maturity properties. Sakukei4, mutated from Enrei, showed later maturity than that of Enrei, and 882-2, mutated from Shinpaldalkong2, showed earlier maturity than that of Shinpaldalkong2. The plant and nodule dry weights at R6 stage of Sakukei4 showed the smallest decrement and those of SS2-2 was showed the largest decrement by the delay of planting time. The photosynthetic rates of Sakukei4 during the late reproductive growth period were slowly decreased, however those of SS2-2 were steeply decreased in two planting time treatments. Overall, the growth of Sakukei4 was decreased slowly, however the growth of SS2-2 was decreased sharply according to the delay of planting time. The percentage of seed yield of Sakukei4 in June planting plot compared with May planting plot at R8 stage was $92\%$, which was the lowest decreasing rate of yield among the cultivars, and in the case of SS2-2, it was in $76\%$, the highest one. These results indicated that the responses of supernodulating mutants by the delay of planting time were very similar to the wild types. This means supernodulating characters in supernodulating soybean mutants might not affect to the maturity property. Additionally, the maturity property could be considered as an important characteristics to decide or to select on the developments of supernodulating soybean mutants, which have a low productivity by an excessive nodules, especially.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.556-560
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• 1997

The removal efficiency of COD and the production of ${\delta}-aminolevulinic$ acid (ALA) were concurrently investigated for both purifying the soybean curd wastewater of high BOD and utilizing the wastewater as a renewable substrate of ALA production using Rhodobacter capsulatus KK-10. Its wastewater was a favorable media for the growth of photosynthetic bacteria in terms of its environmental characteristics having COD/BOD rate of 0.98, ratio of BOD : N : P=100 : 6 : 4, BOD/N ratio of 17.2, lactic acid of 1,080 ppm. Its COD value wastewater was decreased to 94% and dry cell weight was approached to about 1.2 g/l after cultivation of the photosynthetic bacteria for 4 days. By the addition of 15 mM levulinic acid (LA) into the wastewater at the middle log phase of cell growth, the amount of ALA secreted was 55 mg/l. The ALA production was considerably increased to 114 mg/l under the cultural condition of 15 mM supplementations of glycine and succinate with LA at the same period. Furthermore the maximum ALA production of 120 mg/l and COD removal efficiency of 92% were accomplished in the soybean curd wastewater enriched with one addition of 15 mM LA and three serial additions 15 mM ALA precursors.