• Journal of Ecology and Environment
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• v.48 no.3
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• pp.277-284
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• 2024

Background: Newly introduced transgenic plants can outcompete native species in natural ecosystems, threatening the biodiversity of a country. This study ascertained the weediness potential of plants according to the seed amount under the assumption that transgenic seeds were unintentionally spilled. Using sunflowers as the study system, 0, 50, 100, and 150 seeds were sown in 1 m × 1 m and 2 m × 2 m plots, and seed germination, survival, flowering, and competition between the surviving and wild plants were investigated. Results: There was no significant difference in the germination rate of sunflowers depending on the cultivar, but differences were observed depending on the sowing density and plot size. As the number of seeds sown increased, the flowering and seed maturation of sprouted plants occurred earlier; the plant height and flower length of the surviving plants decreased. In addition, as the number of seeds increased, not only did the early importance of sunflowers increase, but the period of dominance over weeds also improved. Conclusions: These results suggest that the weediness potential of sunflowers varies with the number of seeds at the time of release, which may affect germination and growth, and compete with weeds in transgenic plants.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.749-758
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• 2023

An understanding of safety problems pursuant to environmental release of GM (Genetically Modified) crops is considered important. Among the recognized safety problems, the possibilities of weediness and ecosystem invasion are constantly being validated. We herein compared the growth characteristics and germination rate of soybeans formed by hybridization with vitamin A-enhanced soybeans carrying an introduced gene that increases β-carotene content. We also examined overwintering, survival, and weed competitiveness to evaluate hybrid ecological impact on long-term unmanaged cultivatable land. These studies revealed that the hybrid soybeans exhibited intermediate growth characteristics and germination rate compared with the vitamin A-enhanced soybeans and wild soybeans, or exhibited traits similar to those of the maternal strain. Overwintering experiments were conducted by planting seeds at depths of 0, 5, 10, and 20 cm and recovering them after three or five months. After five months, all seeds at depths more than 5 cm lost viability. Among seeds recovered after three months, only wild soybeans retained viability at depths of more than 5 cm. Survival and weed competitiveness were assessed by sowing each type of seed and performing no irrigation, or pest or weed control. Quantitative assessment of numbers of individual soybean plants that appeared in the experimental plot revealed that all plants germinated after sowing, but only wild type plants survived overwintering. These studies suggest that both GM soybeans and hybrid soybeans cannot survive in uncultivated land even if they are released into the environment, which indicates less possibility of ecosystem invasion and weediness.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.160-166
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• 2011

The purposes of this study were to analyze the weediness potential associated with 'Vitamin A enforced rice' and to evaluate the relationships between growth characteristics and environmental adaption related to survival ability in the natural environment. 'Vitamin A enforced rice', 'Nagdong', donor variety of 'Vitamin A enforced rice' and three other varieties were used for this study. The 'Vitamin A enforced rice' was experimented according to ratio of ripened grain, shattering of grain, germination traits, germination ratio of low temperature, emergence ratio after wintering, ratio of viviparity, and growth ratio after ratooning ability. 'Vitamin A enforced rice' was not significant between 'Nagdong' and other varieties in seven characters. Germination ratio was similar of Vitamin A enforced rice' and 'Nagdong', but average germination ability of was different at low temperature. Also, shattering of grain and germination ratio of alternating temperature were significant between 'Nagdong' and other varieties. These results suggested that the relationships between growth characteristics and environmental adaption in 'Vitamin A enforced rice' could be applied to the stability of weediness potential and biosafety guide in GM rice.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.256-262
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• 2012

This experiment was conducted to determine the agronomic characteristics for selection of the excellent barnyard millet and the herbicidal response for their weediness prevention in paddy rice. IT170609, IT195422 and EV2012 have produced more dry matter compared to other barnyard millets tested. In varietal characteristics by heading date, IT170609 showed medium maturing type and IT195422 and EV201 had late maturing type. The germination rate of IT170609, IT195422 and EV2012 on temperature was higher than Echnochloa oryzicola of native species, and it was definitely distinctive at 20 and $25^{\circ}C$. In the herbicidal response for their weediness prevention in paddy rice, imazosulfuron+benzobicyclone+penoxsulam SC showed control effect the extend of over 90% to IT170609, IT195422 and EV2012. Cyhalofop-butyl EC, penoxsulam SC and metamifop EC were very effective by 6~7 leaf stage of barnyard millets tested.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.15-22
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• 2013

The phenotypic traits of herbicide-tolerant transgenic rice were compared with those of wild type (Dongjin) as well as two accessions (Hwaseong-aengmi 1 and Gwangyang-aengmi 12) of weedy rice. This study was conducted to investigate whether unintentional alterations in phenotypic characteristics occurred in the transgenic rice and whether the altered traits were similar to those in the two weedy rices. All qualitative traits studied were similar in the transgenic or wild-type rice. On the other hand, awn presence, flag leaf attitude and grain color differed considerably between herbicide-tolerant transgenic rice and weedy rice. As for quantitative traits, plant height, the number of tillers per plant and shoot dry weight were significantly greater for weedy rice than transgenic or wild-type rice. Grain weight per plant and 1000-grain weight of transgenic (or wild-type) rice were significantly greater than those of weedy rice. Transgenic rice shattered less than the other rices. Amylose and protein contents in embryos of transgenic rice were significantly different from those of weedy rice. The potential for weediness of the transgenic rice may be assessed using phenotype comparison between transgenic and weedy rice as shown in this study.

• Journal of Life Science
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• v.32 no.8
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• pp.641-646
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• 2022

There are concerns about the environmental release of living modified organism (LMO) maize created to increase yields. In fact, there are cases in which LMO crops for feed have been leaked in Korea to form autoite colonies, and concerns about LMO spill are intensifying. In this study, the possibility of environmental outflow and occurrence of native organisms was analyzed using maize feed and seeds distributed in Korea. In the evaluation of the possibility of spontaneous occurrence of maize in the event of an unintentional release of maize feed made by crushing maize, the incidence rate of maize was 0.01%, which was extremely low compared to the germination rate of maize seeds. A survey of the dormant rate of maize showed that all maize seeds collected every month were dead. In the germination rate test by temperature using Daehak wax corn and Kwangpyeongok, high germination rates were found at 20℃ and 30℃, and relatively low germination rates were found at 10℃ and 40℃. In addition, all germination tests showed a higher germination rate Daehak wax corn than Kwangpyeongok. The difference between domestic and overseas cultivation maize was confirmed through a survey on the agricultural properties of three varieties of maize. The data obtained through this experiment could be the basis for the evaluation of the weediness potential of environmental risk assessment and technology to suppress the occurrence of autoite in preparation for future LMO spills.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.136-136
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• 2017

In agriculture, the rice is the one of important things. Many farmers and scientists have long tried to increase the yield of rice. So many technologies have been developed these days. One type of technology has given rise to a host of concerns and questions, namely Genetically Modified Organisms (GMOs). The increasing cultivation of GM crops has raised a wide range of concerns with respect to food safety, environmental effects and socio-economic issues and now commercially planted on about 100 million hectares in some 22 developed and developing countries. The scientific evidence concerning the environmental and health impacts of GMOs is still emerging, but so far there is no conclusive information on the definitive negative impacts of GMOs on health or the environment. Nevertheless, public perceptions about GMOs in food and agriculture are divided with a tendency toward avoiding GM food and products in many developed and developing countries. Also Korea is one of that country and is not allow the GMOs now. So I studied whether these GMOs are actually dangerous for environment and whether there are differences in cultivar characteristics such as germination test with TTC tetrazolium, germination test in frozen soil and gene-flow test with glufosinate and strip-bar test. With these experiments, we evaluated the agricultural safety of GM rice and to identify and assess environmental risks.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.190-201
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• 2022

Background: The introduction of new living modified (LM) crops may pose a latent threat to the biodiversity of each country. Here, we used sunflowers (Helianthus annuus L.) as a study system to investigate the potential for invasiveness of LM crops under different environmental conditions when released into a natural ecosystem in South Korea. We examined the seed germination, survival, and flowering of sunflowers under competition with wild plants at different sowing dates (March-December) and plot sizes (1 m × 1 m and 2 m × 2 m). Results: The germination rate showed a significant difference according to the sowing date. In addition, several sunflowers survived in plots with a high germination rate, which also led to a higher flowering rate. We found that the smaller the plot, the smaller the area available for inter-species competition, and the higher the number of surviving sunflower plants. The relative dominance and importance value of the species varied significantly between the sowing dates; in particular, sunflowers sown in March could compete with wild plants for longer than those sown on other sowing dates. Conclusions: These observations indicate that the potential for invasiveness of sunflowers differs depending on the environmental conditions and seed density at the time of release.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.560-566
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• 2016

Imports of genetically modified (GM) soybeans (Glycine max) for food or feed consumption in Korea have been increasing. Although the cultivation of GM soybeans has not yet been allowed in Korea, the number of field tests for GM soybeans has also been rising. This study was conducted to investigate whether herbicide tolerant GM soybean can survive and persist in uncultivated environments when they escape from transportation routes or from isolated fields. Seeds of GM and non-GM soybeans and wild soybeans (Glycine soja) were buried in 2 and 15 cm soil depths and their viability was examined after 1, 2, 6, and 10 months. GM and non-GM soybean seeds completely lost their viability within six months of burial, whereas seeds of wild soybean maintained their viability during the study period. Seeds of soybean and wild soybeans that were sown on the soil surface germinated and grew to vegetative cotyledon stage. Seedlings of GM and non-GM soybean did not compete well with weeds, including Cerastium glomeratum, Alopecurus aequalis var. amurensis, Capsella bursa-pastoris, Conyza canadensis, Stellaria aquatica, and Erigeron annuus. Also, GM soybean did not survive through winter. However, wild soybeans competed well with the weeds and became dominant in August. Herbicide tolerant GM soybean is unlikely to persist under uncultivated environments and to become weeds.

• Journal of Plant Biotechnology
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• v.38 no.2
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• pp.105-116
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• 2011

Transgenic zoysiagrass (Zoysia japonica Steud.) expressing the bar gene inserted in the plant genome has been generated previously through Agrobacterium tumefaciens-mediated transformation. The GM zoysiagrass (event: JG21) permits efficient management of weed control of widely cultivated zoysiagrass fields, reducing the frequency and cost of using various herbicides for weed control. Now we have carried out the environmental risk assessment of JG21 prior to applying to the governmental regulatory agency for the commercial release of the GM turf grass outside of test plots. The morphological phenotypes, molecular analysis, weediness and gene flow from each test plot of JG21 and wild-type zoysiagrasses have been evaluated by selectively analyzing environmental effects. There were no marked differences in morphological phenotypes between JG21 and wild-type grasses. The JG21 retained its stable integration in the host plant in T1 generation, exhibiting a 3:1 segregation ratio according to the Mendelian genetics. We confirmed the copy number (1) of JG21 by using Southern blot analysis, as the transgenic plants were tolerant to ammonium glufosinate throughout the culture period. From cross-fertilization and gene flow studies, we found a 9% cross-pollination rate at the center of JG21 field and 0% at distances over 3 m from the field. The JG21 and wild-type zoysiagrass plants are not considered "weed" because zoysiagrasses generally are not dominant and do not spread into weedy areas easily. We assessed the horizontal gene transfer (HGT) of the transgene DNA to soil microorganisms from JG21 and wild-type plants. The bar gene was not detected from the total genomic DNA extracted from each rhizosphere soil of GM and non-GM Zoysia grass fields. Through the monitoring of JG21 transgene's unintentional release into the environment, we found no evidence for either pollen mediated gene flow of zoysiagrass or seed dispersal from the test field within a 3 km radius of the natural habitat.