• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.201-201
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• 2017

Delayed stem senescence of soybean is a phenomenon of retarded leaf and stem yellowing, where plants maintain a high stem water content and remain chlorophyll in leaf and stem at maturity stage. This phenomenon was one of the most important physiological disease in Japanese soybean cultivation. The occurrence of delayed stem senescence was affected by sowing time. And the most of Japanese field, soybean seeds were sowed in June. June is the rainy season in Japan, and the soil water content of field become higher in this season. In this study, the effects of late sowing (July sowing) on the yield and the occurrence of delayed stem senescence in soybean cultivars Enrei, Tachinagaha and Ayakogane were examined from 2013 to 2015, in the experimental farm at Nihon University (Fujisawa-city, Kanagawa, Japan). The seeds of all cultivars were sowed in June (June-normal density plot) or July (July-normal density plot, July-high density plot and July-super high density plot) in field experiment. The pot experiments were carried out in 2014. In all cultivars, the yield of July-high density plot and July-super high density were higher than that of June normal density plot. And the yield of June-normal density plot was the same as that of July-normal density plot. In all cultivars, the occurrence of delayed stem senescence was increased by seeding in June sowing. And in July sowing plots, no significance difference in the occurrence of delayed stem senescence was observed among density plots. One of reason about the increasing the occurrence of delayed stem senescence in June-normal plot was the increasing of the damaged seeds by bean bugs. Add one of reason about the decreasing of the occurrence of delayed stem senescence of July plots was the decreasing of the amount of cytokinin supplied from root to top and water stress after the flowering time was improved compared with the June plot. In conclusion, the yield of Enrei, Tachinagaha and Ayakogane were not changed by changing the sowing time from June to July. In all cultivars, the occurrence of delayed stem senescence were decreasing by seeding in July.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.188-194
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• 2023

This study aimed to derive the basic wood density, one of several carbon emission factors, for carbon accounting of bamboo forests in Korea. Bamboo is mainly distributed in Jeollanam-do and Gyeongsangnam-do provinces, and 101 sample trees were selected for each of the three species (Phyllostachys nigra var. henonis, P. bambusoides, and P. pubescens). The basic wood density derivation used the KS F 2098 method. The measurements showed that the basic wood density was 0.83 g/cm³ for P. nigra var. henonis, 0.81 g/cm³ for P. bambusoides, and 0.72 g/cm³ for P. pubescens. However, the bamboo distribution area in Korea is not very large, and P. pubescens grows in one area only. Therefore, the basic wood density that can be applied to bamboo was 0.79 g/cm³. Evaluation of the uncertainty of the extracted basic wood density showed a very low value of 1.61%, which confirmed the reliability of the basic wood density derived from this analysis. The basic wood density, biomass expansion factor, and root-to-shoot ratio were used to calculate the carbon storage capacity of one bamboo plant and expanded to calculate the capacity for a hectare of bamboo. Carbon storage and absorption of bamboo were calculated by applying a carbon-emission factor, such as the basic wood density. These study results are expected to contribute to the carbon-neutral policy and forest management direction in Korea.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.140-145
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• 1995

This experiment was carried out to investigate the effect of plant spacing on the growth and root yield at different harvesting year in Astragalus membranceus. A local variety collected in Jung Sun. Kang Won was used on the 30 and 40cm row spacing, with different spacing between plant of 5, 10, 15, 20cm respectively. Nitrogen, phosphorus and potassium fertilizers were applied as 6, 8 and 9kg/10a respectively, with compost of 1,000kg/10a. Branches, root length, root diameter and root weight were increased in the sparse planting compared with the dense planting. But emergence date, flowering date, stem height and node number were not significantly changed with plant spacing. The highest root yield was 211.8kg/10a at the $30{\time}10cm(67\;plants/m^2)$ in 1 year old plants of Astragalus membranceus. In case of two years old plants, branches, node number, root length, root diameter and root weight were increased in the sparse planting compared to the dense planting. But harvesting ratio was decreased in the dense planting, The highest dried root yield was 292kg/10a at the $40{\time}10cm\;(25\;Plants/m^2)$. In case of 3 years old plants, aerial part and root growth pattern were similar to the 2 years old plants, The dried root yield was highest(623kg/10a) in the $40{\time}10cm(25plants/m^2)$.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1518-1521
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• 2008

Bacteria sense their population density and coordinate the expression of target genes, including virulence factors in Gram-negative bacteria, by the N-acylhomoserine lactones (AHLs)-dependent quorum sensing (QS) mechanism. In contrast, several soil bacteria are able to interfere with QS by enzymatic degradation of AHLs, referred to as quorum quenching. A potent AHL-degrading enzyme, AiiA, from Bacillus thuringiensis has been reported to effectively attenuate the virulence of bacteria by quorum quenching. However, little is known about the role of AiiA in B. thuringiensis itself. In the present study, an aiiA-defective mutant was generated to investigate the role of AHA in rhizosphere competence in the root system of pepper. The aiiA mutant showed no detectable AHL￢-egrading activity and was less effective for suppression of soft-rot symptom caused by Erwinia carotovora on the potato slice. On the pepper root, the survival rate of the aiiA mutant significantly decreased over time compared with that of wild type. Interestingly, viable cell count analysis revealed that the bacterial number and composition of E. carotovora were not different between treatments of wild type and the aiiA mutant. These results provide evidence that AHA can play an important role in rhizosphere competentce of B. thuringiensis and bacterial quorum quenching to Gram-negative bacteria without changing bacterial number or composition.

• Food Science and Preservation
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• v.5 no.3
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• pp.231-238
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• 1998

The effects of temperature(0, 5, 10 $^{\circ}C$), sawdust removal in root part and packaging conditions on the respiration and keeping qualities were evaluated. Higher respiratory activity, weight loss and stipe elongation were observed at higher temperature. Removal of sawdust part slowed down the rate of stipe elongation with little effect on the respiration rates, and therefore improve the quality preservation. The modified atmosphere packaging of 100g mushroom using hermetically sealing by 30 $\mu\textrm{m}$ polypropylene (CPP) and low density polyethylene (LDPE) films were effective in preserving the quality such as visual appearance and Hunter L value, and reducing weight loss at 0$^{\circ}C$, 5$^{\circ}C$ and 10$^{\circ}C$ compared to perforated packages.

• Journal of Ecology and Environment
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• v.37 no.2
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• pp.81-90
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• 2014

This study examined the main factors affecting the distribution of Phytolacca americana, an exotic plant species in Korea, in coastal sand dunes. The areas examined from June 2004 to February 2006 were in Sindusagu where was located on Sindu-ri, Wonbuk-myen, Taean-gun, Chungcheongnam-do. The vegetation, sediment properties, sizes and ages of Robinia pseudoacacia, P. americana and Pinus thnunbergii and spatial distribution of P. americana were assessed. Firstly, correlation coefficients (CC) between P. americana's root biomass and sediment properties were not significant. Secondly, of the four community types, P. americana was not in the mixed herbaceous community and its density was the highest in the P. thunbergii-R. pseudoacacia and R. pseudoacacia community The Poisson distribution analysis revealed the distribution of P. americana to be severely clumped. The root biomass of P. americana and the basal area of R. pseudoacacia were significantly correlated, but the CCs between P. thunbergii and other two species were not significant. The ages of P. americana and R. pseudoacacia in a quadrat were significantly correlated. Thirdly, P. americana's ages in a quadrat were mostly similar to each other. Therefore, the spatial distribution of P. americana was largely influenced by R. pseudoacacia but not by the sediment properties, and plants in a narrow area were concurrently germinated.

• Journal of Periodontal and Implant Science
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• v.43 no.3
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• pp.136-140
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• 2013

Purpose: The aim of this study was to identify a role for endodontic intervention in enhancing the regenerative potential of the periodontal ligament when combined with periodontal treatment in seriously involved teeth with a secondary endodontic component. Methods: Patients who exhibited radiolucency extending to the periapical region, abnormal electric pulp testing values, and deep probing depth derived from primary periodontal disease with secondary endodontic involvement were included. Intentional root canal treatment was applied to those teeth in which the apical lesions were presumed to communicate with those of the periodontal lesion of the teeth that remained vital. In all three selected cases, regenerative periodontal therapy incorporating either bone graft or guided tissue regeneration was instituted 3 months after the endodontic intervention. Results: Remarkable enhancement in radiographic density was noticeable around the affected teeth as evidenced by changes in radiopacity. There was a significant reduction in the probing pocket depth and gain in the clinical attachment level. Chewing discomfort gradually disappeared from the commencement of the combined treatment. Conclusions: An intentional endodontic intervention may be a worthwhile approach for the sophisticated management of teeth suffering from serious attachment loss and alveolar bone destruction with concomitant secondary endodontic involvement.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.1-9
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• 2012

In this study, 200 isolates of fluorescent pseudomonads were isolated from different fields of East and West Azarbaijan and Ardebil provinces of Iran. These bacterial isolates were screened on the basis of a dual culture assay, the presence of known antibiotic genes, and their ability to successfully colonize roots and to promote plant growth. Twelve isolates exhibited 30% or more inhibition of mycelia growth of $P.$ $drechsleri$. Genes encoding production of the antibiotics 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid, and pyoluteorin were detected in some strains but none of the strains possessed the coding gene for production of antibiotic pyrrolnitrin. In an $in$ $vitro$ test for root colonization, the population density on roots of plants treated with most of the above strains was more than 6 $\log_{10}$ CFU $g^{-1}$ roots, with a maximum of 7.99 $\log_{10}$ CFU $g^{-1}$ roots for strain 58A. Most of the strains promoted significant plant growth in comparison to non-treated controls. In green house studies, the percentage of healthy plants in pots treated with strains 58A and 8B was 90.8% and 88.7%, respectively. The difference between these treatments and treatment with the fungicide metalaxyl was not significant.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.417-420
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• 1993

Changes in color intensity of Hololeion maximowiczii(HM) roots which were treated with freeze drying (FD), $50^{\circ}C$ hot air drying (HAD) and $50^{\circ}C$ hot air drying after steam blanching (HADB) were investigated in this study. Color of HADB was yellow-green while other treatments showed bright brown color. In brown color intensity, optical density at 420 nm of FD treatment was highest but HADB treatment showed the highest value in ultra violet spectrum. Water soluble pigment of HM in state of aquous solution was more unstable for heat treatment than that in state of powder. Activation energy for decomposition of the pigment was 20.9 kcal/mole between $90{\sim}100^{\circ}C$ but 50.6 kcal/mole between $80{\sim}90^{\circ}C$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.419-421
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• 2009

The freezing point would be different as the atmospheric pressure and humidity change. So if we can measure the transparency of ice, it should be easy that we approximate a freezing process and estimate the density of ice. This paper presents the method for estimating the transparency of ice in images. First, ice images are mapped to the $CIEL^*a^*b^*$ color space, and we make a new index for the ice transparency by using the average of $L^*$ and RMS(Root Mean Square) Contrast. In this case, the new index is better than the other existing method, i.e, Weber contrast, and Michelson contrast.