• Toxicological Research
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• v.20 no.2
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• pp.101-108
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• 2004

The different social reflections about the benefits and the potential risks of genetically modified (GM) crops have evolved with .different reactions in different countries. Many countries including Korea are working toward setting down new guidelines. Korea requires companies to label all food that contains more than 3% GM ingredients. One of the rapid and convenient detection methods of GM ingredients is amplification of the introduced DNAs by polymerase chain reaction (PCR). Many PCR kits for this purpose are commercially available. The objective of this study was to evaluate performance of commercialized GM crop detection kits. The results showed that 6 out of 15 kits tested did not meet the requirements even purposed by the manufacturers themselves in terms of stability, reproducibility, and detection limits, suggesting a potential quality control problem in their design stage or production line. The evaluation also suggests that, although the duplex and triplex detection kits allowed unambiguous detection in a single PCR reaction, the monoplex detection kits were the most sensitive to the detection of GM ingredients. The detection limits also differ between soybean and corn. Results from this study will be useful in the development of sound qualitative tracking systems of GM ingredients for monitoring throughout the cultivation of GM crops, their trans-boundary movement, and food production using GM grains as well as for complying with government guidelines associated with GM crops.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.309-315
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• 2020

Advances in biotechnology have led to progress in crop genetic engineering to improve agricultural productivity. The use of genetically modified (GM) crops has increased, as have consumers' and regulators' concerns about the safety of GM crops to human health, and ecological biodiversity. As such, the identification of GM crops is a critical issue for developers and distributors, and their labeling is mandatory. Multiplex polymerase chain reaction (PCR) has been developed and its use validated for the detection and identification of GM crops in quarantine. Herein, we established a simultaneous detection method to identify four GM maize events. Event-specific primers were designed between the junction region of transgene and genome of four GM maize lines, namely 5307, DAS-40278-9, MON87460, and MON87427. To verify the efficiency and accuracy of the multiplex PCR we used specificity analysis, limit of detection evaluation, and mixed certified reference materials identification. The multiplex PCR method was applied to analyze 29 living, modified maize volunteers collected in South Korea in 2018 and 2019. We performed multiplex PCR analysis to identify events and confirmed the result by simplex PCR using each event-specific primer. As a result, rather than detecting each event individually, the simultaneous detection PCR method enabled the rapid analysis of 29 GM maize volunteers. Thus, the novel multiplex PCR method is applicable for living modified organism volunteer identification.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.614-621
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• 2012

Although there is a broad dispute over genetically modified foods on safety, the worldwide adoption of transgenic crops is rapidly increasing. The objectives of this study were to identify trends in the effects of transgenic on crop yields and examine the effect of agricultural variables including crop type, biotech trait, tillage system, and yield environment on corn and soybean yield. A meta-analysis from the 34 peer-reviewed scientific literatures was conducted to compare the crop yield between transgenic crops and conventional varieties. Results showed that the yield of transgenic corn and soybean was strongly dependent on growing conditions. Transgenic hybrids had higher yield potential in the low crop yield environments such as high weeds and/or insect infestation, low soil water, and cool temperature conditions, while transgenic crops did not have yield advantages in high yield environments. The results from this study suggest that producers should consider the potential yield environmental conditions and possible yield reductions when producers choose crop hybrids in their fields.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.303-308
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• 2015

Cultivating genetically modified (GM) crops is believed to be a practical solution to meet the increasing food demand, but GM crops are not legal in Korea mainly due to food safety issues. Even though the general public might not be ready to consume GM food, GM crops are imported and consumed as food and feed. To analyze farmers's willingness to grow GM crops for feed, a survey was conducted among crop farmers and 640 valid responses were collected by mail. In the questionnaire, the farmers were asked to select either 'yes' or 'no' if they were willing or not willing to cultivate GM rice and GM grass, respectively, under the given hypothetical income increase rate (i.e., 10%, 20%, 30%, 40%, 50%, 60%, or 70%). Logit regression was used to estimate the two dichotomous choices by explanatory variables including hypothetical income increase rate. The results show that farmers are willing to cultivate GM rice and grass when their income is expected to increase by 47% and 43%, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.227-231
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• 2004

A total of 219 polymerase chain reaction tests of genetically modified (GM) DNA sequences in soybean seeds and soybean sprouts were conducted during 2000-2001. No CM gene was found in 96 tests of soybean seeds. However, either a functional CP4EPSPS gene or the 355 promoter gene was found three times in 2000 and eight times in 2001, in between 0.01 and 0.17％ of soybean spout products, in 123 tests. Since the amount of GM genes was much less than the threshold limit of 3％, none of the 11 positive soybean-sprout samples needed to be libeled GM crops. Of these, seven sprout samples were from domestic seeds and four were from seeds imported from China. To find the contamination route, the raw materials, seed surface, floor of the storage room, area around the selection machine, surface of the packaging film and corn powder used in the package were tested. The 35S promoter gene was detected in only two samples of the corn powder (0.1％). Although we could not find the cause of the GM contamination, the sprout package film is one possibility. In total,8.9％ of the soybean sprout tests were GM positive, but the amounts were much less than the threshold of 3％. This means that there are frequent false-positives and these would threaten the sprout industry if GMO were decided qualitatively. Food companies should make their safety data available to the public and make an effort to address people's concerns about GM food more openly. In addition, there is a need to establish a quantitative test for GM genes in sampled water and a sampling method for raw materials.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.350-354
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• 2017

Conyza canadensis is the weed species which most frequently develops resistance to glyphosate in many agricultural crop fields. The continuous use of glyphosate has resulted in the spontaneous occurrences of resistant biotypes. This research was conducted to investigate the response of suspected C. canadensis biotypes to glyphosate. Seeds of C. canadensis were collected from 18 sites in tangerine orchards in Jeju province of Korea. In the preliminary screening, 6 resistant and 12 susceptible biotypes were found at the recommended glyphosate rate ($3.28kga.i.ha^{-1}$). The susceptible biotypes were completely killed at the field application rate whereas the resistant biotypes were initially injured but recovered 14 days after glyphosate application. This is the first case of glyphosate resistance found in Korea despite the national ban on genetically modified glyphosate tolerant crops cultivation. Extended monitoring should be conducted to understand how widely spread the glyphosate resistant C. canadensis is and to estimate the severity of this weed problem in the tangerine orchards of Korea.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.301-308
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• 2009

Higher agricultural commodity prices are a particular concern for food importing countries like Korea that has a very low self-sufficiency ratio. Korean people eat approximately 4.5 million metric tons of rice each year, which is met without a problem by domestic production. The domestic production of corn and soybean which are important raw materials for commercial food processing and livestock feed is only minimal. Demands of corn and soybean in Korea are approximately 7.2 million and 1.3 million metric tons per year, respectively. Since Korean consumers are reluctant to accept biotech (GM) foods, Korean food processors are fighting an up-hill battle in purchasing non-biotech (non- GM) crops which are becoming scarce.

• Journal of Plant Biotechnology
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• v.37 no.3
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• pp.319-326
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• 2010

An interest in the production of seed-oil based fuel and raw materials, which comes from renewable plant sources, has been intrigued by the phenomenon of global warming and shortage of fossil fuels. Rapeseed (Brassica napus) is the most important oilseed crop, which produces seeds with 40% oil. It is desirable to develop genetically modified rapeseed producing oils, which can be easily converted to biodiesel. As an initial step for development of genetically modified rapeseed for the production of biofuels or bio-based materials, Korean rapeseed cultivars, Naehan, Youngsan, Tammi and Halla, were analyzed. Four Korean rapeseed cultivars produce 32 to 40% oil of seed dry weight, which is rich in oleic acid (more than 60 mole%). The cotyledonary petioles of rapeseed cultivar, Halla, were transformed using Agrobacterium tumefaciens strain GV3101, carrying the uidA gene encoding $\beta$-glucuronidase (GUS) as a reporter gene and the phosphinothricin acetyltransferase (PAT) gene as a selectable marker. The stable integration of PAT gene in the genome of transgenic rapeseeds was confirmed by PCR analysis. Expression of uidA gene in various rapeseed organs was determined by fluorometric assay and histochemical staining. Transformation efficiency of a Korean rapeseed Halla cultivar was 10.4%. Genetic inheritance of transgenes was confirmed in $T_2$ generation.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.187-191
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• 2014

The cultivation area and use of genetically modified (GM) crops have been increased continuously over the world. Concerns about the potential risks of GM crops are also increasing. Safe management for the development and production of GM crops is required according to Living Modified Organism Act in Korea. Planning about the methods, duration, and frequency of environmental monitoring is also required for commercial use of GM crops. GM Zoysia japonica Steud. (event name: JG21) expressing resistance to glufosinate-ammonium has been generated previously. By using gamma ray treatment to JG21 we also developed male sterility and dwarf Z. japonica (event name: JG21-MS). The objective of this study was to establish the monitoring system for environment release of JG21-MS. In this study we extracted RNA from JG21 and JG21-MS and conducted RAPD (random amplified polymorphic DNA) method to distinguish JG21 and JG21-MS.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.235-240
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• 2002

We report the new method for the screening of genetically modified potato by competitive duplex-PCR using the potato specific single oligomer primer for the internal control and CaMV 35S promoter or NOS terminator specific primers. The single oligomer primer (rAGU4A) amplify the potato specific internal control band from the homozygous potato genomic DNA in the RAPD profiles of all analyzed potato varieties. The 530 bp internal control DNA was amplified independently to CaMV 35S promoter or NOS terminator DNA and identified as repetitive or microsatellite DNA of potato (AF541972). With this new technique, the transgenic potatoes which were transformed with vectors contained the different foreign genes are analyzed. In case of the commercialized transgenic potato varieties, 'Hew Leafs', those two genetic factors are used for promoter and terminator respectively So, this new PCR technique should be a promising method of cost effective and accurate screening for the commercialized GM potatoes on market.