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Open Access Journal

Korean Journal of Environmental Agriculture

p-ISSN 1225-3537
e-ISSN 2233-4173

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The Korean Journal of Environmental Agriculture is an official publication of the Korean Society of Environmental Agriculture. It is published quarterly a year, March 31, June 30, September 30, and December 31, and distributed to more than 700 members including individuals and institutions. The abbreviated title is ‘Korean J. Environ. Agric.’ The journal was launched on June 30 in 1982, the Print ISSN was issued on October 30, 1992 (Volume 11, No. 2) while the Online ISSN was issued on December 31, 2010 (Volume 29, No. 4). Whole document of a part of the articles in this journal are listed in the Directory of Open Access Journals (DOAJ, http://www.doaj.org), Google Scholar and Korea Citation Index (KCI). The full text is freely available from http://www.korseaj.org.

Creative Commons Attribution Non-Commercial License

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Current Issue 2021. Vol.40, Iss.1more..

  • Identification of G Protein Coupled Receptors Expressed in Fat Body of Plutella Xylostella in Different Temperature Conditions
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    BACKGROUND:

    G protein-coupled receptors (GPCRs) are widely distributed in various organisms. Insect GPCRs shown as in vertebrate GPCRs are membrane receptors that coordinate or involve in various physiological processes such as learning/memory, development, locomotion, circadian rhythm, reproduction, etc. This study aimed to identify GPCRs expressed in fat body and compare the expression pattern of GPCRs in different temperature conditions.

    METHODS AND RESULTS:

    To identify GPCRs genes and compare their expression in different temperature conditions, total RNAs of fat body in Plutella xylostella larva were extracted and the transcriptomes have been analyzed via next generation sequencing method. From the fat body transcriptomes, genes that belong to GPCR Family A, B, and F were identified such as opsin, gonadotropin-releasing hormone receptor, neuropeptide F (NPF) receptor, muthuselah (Mth), diuretic hormone receptor, frizzled, etc. Under low temperature, expressions of GPCRs such as C-C chemokine receptor (CCR), opsin, prolactin-releasing peptide receptor, substance K receptor, Mth-like receptor, diuretic hormone receptor, frizzled and stan were higher than those at 25℃. They are involved in immunity, feeding, movement, odorant recognition, diuresis, and development. In contrast to the control (25℃), at high temperature GPCRs including CCR, gonadotropin-releasing hormone receptor, moody, NPF receptor, neuropeptide B1 receptor, frizzled and stan revealed higher expression whose biological functions are related to immunity, blood-brain barrier formation, feeding, learning, and reproduction.

    CONCLUSION:

    Transcriptome of fat body can provide understanding the pools of GPCRs. Identifications of fat body GPCRs may contribute to develop new targets for the control of insect pests.

  • Photodegradation of Mixtures of Tetracycline, Sulfathiazole, and Triton X-100 in Water
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    BACKGROUND:

    Chemicals such as antibiotics and surfactants can enter agricultural environment and they can be degraded by natural processes such as photolysis. These chemicals exist in mixtures in the environment, but studies on degradation of the mixtures are limited. This study compares the photodegradation of Triton X-100 (TX) and antibiotics [tetracycline (TC) and sulfathiazole (STH)] when they are in a single solution or in mixtures.

    METHODS AND RESULTS:

    TC, STH, and TX solutions were exposed to UV-A for the photodegradation tests for 14 days. The residual TC, STH, and TX concentrations were analyzed by using HPLC. The TC degradation was similar regardless of the presence of TX, while the TX degradation was lower in the presence of TC. The STH degradation was similar regardless of the presence of TX, while the TX degradation was greater in the presence of STH. However, the STH degradation was slower in the TC-STH-TX mixture than in the STH-TX mixture. Also, the TX degradation was negligible in the TC-STH-TX mixture. The results show that the photodegradation of TC, STH, and TX can be different in mixtures. This can be attributed to the different emission and absorption wavelengths of each compound and interaction between these compounds and photoproducts.

    CONCLUSION:

    Overall, this study emphasizes that photodegradation of single chemicals and chemical mixtures can be different, and more studies on single compounds as well as mixtures are required to understand the fate of chemicals in the environment in order to manage them properly.

  • Antibacterial Activity of Streptomyces sp. J46 against Bacterial Shot Hole Disease Pathogen Xanthomonas arboricola pv. pruni
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    BACKGROUND:

    Bacterial shot hole of stone fruits is a seriuos plant disease caused by Xanthomonas arboricola pv. pruni (Xap). Techniques to control the disease are required. In this study, microorganisms with antibacterial activity were isolated to develop as a microbial agent against the bacterial shot hole.

    METHODS AND RESULTS:

    An isolate with the strongest activity among the isolates was identified as Streptomyces avidinii based on 16S rRNA gene sequence analysis and designated Streptomyces sp. J46. J46 showed suppression of bacterial leaf spot with a control value of 90% at 10 times-diluted cell free supernatant. To investigate antibacterial metabolites produced by J46, the supernatant of J46 was extracted with organic solvents, and the extracts were subjected to chromatography works. Antibacterial metabolites were not extractable with organic solvents. Both reverse and normal phase techniques were not successful because the metabolites were extremely water soluble. The antibacterial metabolites were not volatiles but protein compounds based on hydrolysis enzyme treatment.

    CONCLUSION:

    Our study suggests that Streptomyces sp. J46 may be a potential as an microbial agent against bacterial shot hole. Further study to identify the metabolites is required in more detail.

  • Effects of Phosphogypsum Application on Field Soil Properties and Yield and Quality of Garlic (Allium sativum L.)
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    BACKGROUND:

    Globally, large amounts of phosphogypsum (PG), which is a by-product of the phosphate fertilizer production, is deposited in open areas. As PG contains calcium, phosphate, and sulphate, it can be used as a soil amendment in farmlands. This study was conducted to investigate the effects of PG application on properties of field soil and yield and quality of garlic (Allium sativum L.), and to seek appropriate level of PG application into the field.

    METHODS AND RESULTS:

    This experiment was conducted by applying PG at four different levels that were adjusted based on 65% calcium base saturation in the field soil: 0% (control), 50% (PG50, 100 kg/10a), 100% (PG100, 200 kg/10a), and 150% (PG150, 300 kg/10a). Following cultivation, soil electrical conductivity (EC), organic matter, available P and exchangeable Ca increased, whilst soil pH decreased. With increase in PG application level, soil EC and exchangeable Ca increased. PG application increased concentrations of water soluble Ca and SO4 across the soil profile, especially in PG150. The highest yield of garlic was found in PG100 treatment. The plant’s uptake for N, P, Ca, and S increased by PG applications, but that for K decreased. Moreover, concentrations of S-related amino acids such as cysteine and methionine in garlic increased by PG applications. The increased content of nutrients and amino acids with PG supply might improve yield, quality, and favor of the crop.

    CONCLUSION:

    Overall, PG application at 200 kg/10a into a field had the best effect on improving soil fertility as well as yield and quality of garlic. Further studies are required to maximize efficiencies of PG supply in soil management and production of various crops.

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