Current Issue 2017. Vol.36, Iss.4

Orginal Articles

• Effect of Tillage System and Fertilization Method on Biological Activities in Soil under Soybean Cultivation

  Eun-Ji Oh, Ji-Su Park, Jin Yoo, Suk-Jin Kim, Sun-Hee Woo, Keun-Yook Chung / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 223-229

  https://doi.org/10.5338/KJEA.2017.36.4.42

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Tillage systems and fertilization play an important role in crop growth and soil improvement. This study was conducted to determine the effects of tillage and fertilization on themicrobial biomass Cand dehydrogenase activity of soils in a field under cultivation of soybean.

  METHODS AND RESULTS:

  An experimental plot, located in the temperate climate zone,was composed of two main sectors that were no-tillage (NT) and conventional tillage (CT), and they were subdivided into four plots, respectively, in accordance with types of fertilizers (non fertilizer, chemical fertilizer, hairy vetch, and liquid pig manure).Microbial biomass C and dehydrogenase activity were evaluated from May to July in 2016. The microbial biomass C and dehydrogenase activity of NT soils were significantly higher than those of CT in all fertilizer treatments, and they were further increased in hairy vetch treatment than the other fertilizer treatments in bothNTand CT. The dehydrogenase activity was closely related to microbial biomass C.

  CONCLUSION:

  It is concluded that application of green manure combined with no-tillage can provide viable management practices for enhancing microbial properties of soil.

• Temporal Patterns of Pesticide Residues in the Keum, Mangyung and Dongjin Rivers in 2002

  Chan-sub Kim, Hee-Dong Lee, Yang-Bin Ihm, Kyeong-Ae Son / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 230-240

  https://doi.org/10.5338/KJEA.2017.36.4.38

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  To evaluate residues of environmentally concerned pesticides in water system, this monitoring was conducted over three rivers. The residual characteristics and discharging condition of these residues onwater system was investigated.

  METHODS AND RESULTS:

  Total twenty nine sampling sites were selected through main streams and branch streams of Keum, Mangyung and Dongjin rivers, and the water samples from them were regularly collected one month interval, especially biweekly fromMay toAugust in 2002. Of the pesticides monitored, six fungicides which include hexaconazole, isoprothiolane and iprobenfos were detectedwith frequencies of 0.3-50.9%and in their residue level of 0.1-4.7 g/L. Sixteen μ insecticides which include nine organophosphoruses, three carbamates, endosulfan, cypermethrin, buprofezin and fipronil were detected with frequencies of 0.3-32.5% and in their residue level of 0.01-2.8 μg/L. Nine herbicides which include alachlor molinate, anilofos, butachlor, dimepiperate, metolachlor, oxadiazon, pretilachlor and thiobencarbwere detectedwith frequencies of 0.8-22.9% and in their residue level of 0.01-9.07 μg/L.

  CONCLUSION:

  Detection frequencies and residue levels of insecticides and herbicides were the highest in waters sampled inMay and June. Almost pesticides detectedwere for the paddy rice and their residue levels were very low to compare with standard values.

• Acute Oral Toxicity of dsRNA to Honey Bee, Apis mellifera

  Hye Song Lim, Young Jun Jung, Il Ryong Kim, Jin Kim, Sungmin Ryu, Banni Kim, Jung Ro Lee, Wonkyun Choi / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 241-248

  https://doi.org/10.5338/KJEA.2017.36.4.36

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  RNAinterference (RNAi) eliminates or decreases gene expression by disrupting the target mRNA or by interfering with translation. Recently, RNAi technique was applied to generate new crop traits which provide protection against pests. To establish the environmental risk assessment protocol of RNAi LMO in lab scale, we developed dsRNA expression systemusing E. coli and tested acute oral toxicity assay to honey.

  METHOD AND RESULTS:

  The dsRNA expression vector, L4440, was chosen and cloned 240 bp of Snf7 and GFP gene fragment. To develop the maximum dsRNA induction condition in E. coli, we tested induction time, temperature and IPTG concentration inmedia. To estimate the risk assessment of dsRNA to honey bee, it has been selected and cultured with dsRNA supplement for 48 hours according to OECD guideline. As a result, the optimum condition of dsRNA induction was 37℃, 4 hours and 0.4 mM IPTG concentration and the difference between Snf7 and GFP dsRNA molecules from E. coli was not significant in survival and behavior to honey bee. Furthermore, blast search results indicated that effective match of predicted dsRNA fragments were not existed in honey bee genome.

  CONCLUSION:

  In this study,we developed and tested the acute oral toxicity of dsRNA using E. coli expression system to honey bee.

• Quali-Quantitative Analysis of Flavonoids for Mulberry Leaf and Fruit of ‘Suhyang’

  Wan-Taek Ju, O-Chul Kwon, Min-Ki Lee, Hyun-Bok Kim, Gyoo-Byung Sung, Yong-Soon Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 249-255

  https://doi.org/10.5338/KJEA.2017.36.4.39

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Globally, mulberry (Morus sp.) is exploited for feeding leaf to silkworms in order to obtain silk fiber or for animal feedstock production. Also, mulberry fruit is known to a by-product that was produced from mulberry tree after harvesting leaves for silkworm rearing, as a yield and consumption of mulberry fruit was increased, it has been fixing to a new income crop.Mulberry leaves and fruits are used for the health benefits of human beings. Mulberry contains various bioactive components, such as alkaloids and flavonoids. Mulberry flavonoids are an important part of the diet because of their effects on human nutrition. The flavonoids in mulberry leaf and fruit of ‘Suhyang’(Morus alba L.) were determined.

  METHODSANDRESULTS:

  Flavonoids formulberry leaf and fruit of ‘Suhyang’ were analysed using ultrahigh performance liquid chromatography coupled with diode array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS) technique. An UPLC-DAD-QTOF/MS system was used, and identification of mulberry leaves constituentswas carried out on the basis of the complementary information obtained fromLC spectra, MS ions, and MS/MS fragments. The mulberry leaf (16 flavonoids) and fruit (9 flavonoids) were isolated and analyzed from Suhyang using UPLC-DAD-QTOF/MS chromatogram. To the best of our knowledge, Quercetin 3-O-(6''-O-malonyl) glucoside and quercetin 3-O-rutinoside (rutin) was detected on the highest content in leaf and fruit, respectively and further researchwill be devoted to evaluate their biological activity.

  CONCLUSION:

  Obtaining information about the concentration of functional materials inmulberry leaves could contribute to the development and promotion of processed, functional products and offer possible industrial use of ‘Suhyang’, holding promises to enhance the overall profitability of sericulture.

• Response of Germination Rate and Ascorbate Peroxidase Activity to Cryopreservation of Perilla (Perilla frutescens) Seeds with Variable Initial Viabilities

  Young-yi Lee, Myeong-hee Lee, Jung-yoon Yi, Tae-yoon Lee, Eun-ho Son, Hong-jae Park / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 256-262

  https://doi.org/10.5338/KJEA.2017.36.4.34

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Seed of perilla (Perilla frutescens var. japonica Hara) is short-lived in conventional storage conditions. For long-term conservation of plant species, cryopreservation is the method currently available. This study was performed to find out reliable methods for a long-term storage of seeds of perilla as a genetic resource.

  METHODS AND RESULTS:

  Using seeds of 9 perilla cultivars, the effects of desiccation, aging, andcryopreservation on seed germinability and ascorbate peroxidase activity in the seeds were investigated. Initial germinability of the seeds was various, and dry seeds of all cultivars survived cryopreservation without loss of viability. The highest germination was achieved at 4-5% moisture content, and stimulatory effect of cryogenic temperature on the seed germination was observed in some cultivars. Accelerated aging of perilla seeds led to reduction in germination and ascorbate peroxidase activity, and the susceptibility of seeds to agingwas different among the tested cultivars. No significant difference in germination was observed for the aged seeds of control and liquid nitrogen exposed.

  CONCLUSION:

  The results of this study suggest that cryopreservation at 4-5% moisture content would be a suitablemethod for long-termconservation of perilla seeds without detrimental effects on germination.

• Antioxidant and Metalloproteinase Inhibitory Activities of Ethanol Extracts from Lespedeza cuneata G. Don

  Yong Ha Shin, Chang-Khil Song / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 263-268

  https://doi.org/10.5338/KJEA.2017.36.4.40

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Lespedeza cuneata G. Don is a well-known medicinal plant. In this study, the biological activities of L. cuneata extracts were investigated.

  METHODS AND RESULTS:

  L. cuneata shoot was extracted with 30% ethanol and further fractionated with organic solvents. Total phenolic and flavonoid content, antioxidant activity, andmatrixmetalloproteinase inhibition effect of the extract and fractions were measured. Among the tested extract and fractions, the highest contents of total phenolic and flavonoidswere found in ethyl acetate fraction (117.8 mg GAE/g and 35.9 mg QE/g, respectively). Ethyl acetate fraction showed the highestDPPHandABTS radical scavenging activity, and the antioxidant activity of the other fractions followed the order n-hexane fraction>ethanol extract>methyl chloroform>n-butanol fraction. Inhibitory effect on the expression of matrix metalloproteinases (MMP1 and MMP3) was highest in the fraction of ethyl acetate, and n-butanol fraction also significantly inhibited the expression of MMP3. Antioxidant activities of L. cuneata extracts were significantly positively related to their phenolic and flavonoid content.

  CONCLUSION:

  Ethyl acetate fraction of L. cuneata ethanol extract showed potent antioxidant and matrix metalloproteinases inhibitory activities. Those activities might be related to the high total phenolic and flavonoid content of the extract.

• Residual Multi Pesticides Screening of Dead Birds by Orbitrap High Resolution Mass Spectrometry

  Doo-Hee Lee, Bo-Kyong Kim, Seung-Jun Wang, Ki-Dong Son, Hyen-Mi Chung, Jong-Woo Choi / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 269-278

  https://doi.org/10.5338/KJEA.2017.36.4.33

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The objective of this study was to evaluate screening method of residual multi pesticides in dead birds by Orbitrap high resolution mass spectrometry (HRMS) to identify the cause of death for birds .

  METHODS AND RESULTS:

  Extraction and clean-up method of residual pesticides in liver of dead birdswas used QuEChERS (Quick Easy Cheap Effective Rugged and Safe) and method validations was conducted using liquid chromatography and gas chroamtography with triple-quadrupole mass spectrometer (LC/MS/MS and GC/MS/MS) Also, we were evaluated screening method for the determination of residual pesticides in liver of dead birds by LCandGCOrbitrapMass Spectrometry. Results ofmethod validations, Correlation coefficients of thematrixmatched calibration curves were >0.978, and the method detection limits (MDLs) and limits of quantitation (LOQ) were 2.8~72.1 ng/g (18.4 ng/g on average) and 9.0~230 ng/g (58.5 ng/g on average). The accuracy ranged from69.1%to 130% (103%on average), and the precision valueswere less than 14.8%(3.8%on average). The screening of residual pesticides in liver of dead birds by LC and GC Orbitrap HRMS was detectedmonocrotophos, carbofuran, carbosulfan, deltametrin, benfuracarb, carbofuran, phosphamidon, prochloraz in investigated samples.

  CONCLUSION:

  This results showed that accurate mass were extraction of residual pesticides in dead birds by Orbitrap HRMS. It suggested that this screeningmethod is applicable to the residual pesticide analysis for the cause of death as a main tool.

• Residual Characteristics and Monitoring of Cyenopyrafen and Cyflumetofen in Strawberries for Export

  Yeong-Jin Kim, Jong-Hwan Kim, Young-Sang Kwon, Jong-Wook Song, Jong-Su Seo / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 279-287

  https://doi.org/10.5338/KJEA.2017.36.4.35

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Many farmers who cultivate the strawberries for export have used agricultural chemicals which MRL (Maximum Residue Limits) of main export target countries or simultaneous multi-residue analysis in Korea have not been established. Among them, the cyenopyrafen and cyflumetofen were selected and applied to this study to determine the PHI (pre-harvest interval) which is appropriate to the PLS (Positive List System) criterion (0.01 mg/kg) and to investigate the residual amounts in the samples. In addition, Fifty pesticides were monitored to check upwhether it is suitable or not formain export target countries.

  METHODSANDRESULTS:

  Cyenopyrafenand cyflumetofen were spayed out to the strawberries. Samples for residual analyseswere taken formaximum60 days.After sampling, they were extracted by the QuEChERS method and analyzed using the LC-MS/MS. Cyenopyrafen and cyflumetofen were detected in a range of 0.0106 ~2.6517 mg/kg and of 0.0005~1.4480 mg/kg, respectively. From this results, they were found to be suitable for PLS concentration after 30 or 45 days after spray. In addition, they were detected in most samples that were selected at random. Their concentrations were higher than the PLS criterion in the maximum twenty samples. Twelve of pesticides unsuitable for main export target countries have been detected in the monitoring of simultaneous multi-residue analysis. The result indicates they are unsuitable for export since they excesses over PLS criterion.

  CONCLUSION:

  The monitoring result showed it is necessary to establish the pesticide standards of safe use suitable for the PLS criterion. In addition, it is considered continues management and inspection are needed to solve problems caused by unsuitable pesticides in export strawberries.

• Evaluation of Exposure Indicators for Plants by Silicon Tetrachloride Release

  Jae-Seon Park, Jee-Young Kim, Myeong-Ock Kim, Hyun-Woo Park, Hyen-Mi Chung, Jong-Woo Choi / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 288-292

  https://doi.org/10.5338/KJEA.2017.36.4.37

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Silicon tetrachloride reactswithmoisture in the atmosphere to generate hydrogen chloride, which affects the environment. Since silicon tetrachloride and its by-products are dispersed in the atmosphere in a short time after the silicon tetrachloride release into the atmosphere, it is difficult to directly assess the extent of environmental impact. In the present study, the exposure test of silicon tetrachloride or hydrogen chloridewas examined in order to establish the criterion of the range affected by the silicon tetrachloride release, and the actual crops in the area exposed to silicon tetrachloride leakage were analyzed.

  METHODSANDRESULTS:

  For the experiment of exposure to silicon tetrachloride or hydrogen chloride, the leaves of red-pepper and cornwere used in glass sealed containers. In the actual accident area, 59 samples from10 different kinds of cropswere collected. The pretreatment of the samplewas performed by freezing and grinding, and then extracted using distilledwater. The pHand concentration of chloride (Cl^-) ion of the extracted solution weremeasured using pH meter and ion chromatograph, respectively.

  CONCLUSION:

  Exposure to silicon tetrachloride caused visible damage, increasing the concentration of chloride ion, and decreasing the pH as well as hydrochloric acid. In the actual crops of the affected area, the tendency was the same as the result of the laboratory test, and the range of influence could be estimated through the concentration of Cl^- ion over 2,000 mg/kg, and the correlation evaluation between the concentration of Cl^- and pH. Therefore, the concentration of Cl^- ion and the correlation betweenCl^- and pH would be considered as the factors to estimate the influence range of silicon tetrachloride release.

• The Correlation Between Deltamethrin Exposure and Urinary 3-PBA Concentrations in Rats

  Areumnuri Kim, Kyongmi Chon, Kyung-Hun Park, Byeong-Chul Moon, Jin-Ho Ro, Min Kyoung Paik / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 293-298

  https://doi.org/10.5338/KJEA.2017.36.4.41

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Pyrethroids (PYRs) are a widely used insecticide in agriculture and household area. In mammals, PYRs such as deltamethrin is metabolized to 3-phenoxybenzoic acid (3-PBA) in liver that is mainly excreted in urine. This study is designed to single exposure of deltamethrin to rats in a dose-dependent manner and identify the correlation between deltamethrin exposure and its metabolite (3-PBA) in urine.

  METHODSANDRESULTS:

  Exposure levels of deltamethrin were control (0 mg/kg bw), low (0.0705 mg/kg bw), medium(0.705mg/kg bw) and high (7.05mg/kg bw) dose. Lowconcentrationwas derived by ussingKorea predictive operator exposure model (KoPOEM). Dermal exposure persisted for 6 h, and urine specimenswere collected for 24 h. The urinematrixwas removed after a series of procedures and 3-PBA was analyzed by gas chromatography/mass spectrometry.

  CONCLUSION:

  There was a strong correlation (R²=0.83) between the amount of oral exposure to delta me thrin and urinary levelof3-PBAexcreted. In dermal exposure groups of deltamethrin except high-dose, also there was a good correlation between urinary 3-PBA and deltamethrin exposure, but not stronger than in oral deltamethrin exposure groups. Based on these results, therefore, the amount of 3-PBAin urine can be used as a goodmonitoring indicator that reflexing the exposure level of deltamethrin to human body.

• Isolation and Characterization of Colletotrichum Isolates Causing Anthracnose of Japanese Plum Fruit

  Yong-Se Lee, Da-Hee Ha, Tae-Yi Lee, Min-Jung Park, Jong-Bae Chung, Byeong-Ryong Jeong / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 299-305

  https://doi.org/10.5338/KJEA.2017.36.4.32

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Although the filamentous fungal pathogen Colletotrichum species causing anthracnose disease on various fruits including peach, apple, persimmon and grape, there is no report on Japanese plum in Korea.

  METHODS AND RESULTS:

  In 2016, diseased fruits showing typical anthracnose symptoms of Japanese plum were collected in market and ochards. Diseased tissue was cut off and disinfected subsequentlywith 70%ethanol for 1 min, and in 1% sodium hypochloride solution for 1 min, followed by three washes with sterile distilled water. The disinfected tissues were placed onto potato dextrose agar (PDA), and incubated at 25℃ in the dark for 5 to 7 days. For single-spore isolation, conidia were scraped off the plate using a loop, and suspended with 10 mL sterile distilled water. One hundred microliter of the conidial suspension was spread on PDA plates and incubated at 25℃. Finally, one germinated conidiumwas transferred onto PDAplates. Morphological and cultural characteries of colonies and spores of isolated Colletotrichum were observed after 7 to 10 days incubation on PDA. Molecular identification of isolates were analyzed by comparing rDNA-ITS gene sequences with NCBI GeneBank.

  CONCLUSION:

  Of eleven isolates of Colletotrichum isolated from anthracnose diseased Japanese plum fruits, six were identified as C. acutatum, and five as C. gloeosporioides based on diagnostic characteristics such as colony growth rate, shape and size of conidia, and rDNA-ITS sequences. This is the first report of Colletotrichum causing the anthracnose on Japanese plum in Korea.