• Journal of the Korean association of regional geographers
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• v.10 no.4
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• pp.744-756
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• 2004

The purpose of this study is to investigate the natural environments and the changing socio-economic activities of the rice and fruit - centered rural village located in Sangju region, Kyongsangbuk-do. Its results are summarized in the followings. Firstly, most of the rural villages in Sangju region is located on the erosional basin of Sobaek range and the sedimentary region of Nakdong river and the farmer's life of those regions has been influenced by such a natural environment. Secondly, the reproduction structure of population in the rural village of Sangju region had been maintained until the 1970s. After that, however, it was broken because the young generation of the rural villages moved to large cities to get a job or to receive high level of education. Thirdly, the changing path of the rural villages of Sangju region was different based on a type of crop and its related mode of production after the 1980s. The socio-economic structure of the rural village has been developed based on either a rice oriented traditional mode of production or a fruit-oriented commercial mode of production. The two villages, Ch'ekdong 1 ri, Hamch'ang-up and Sinch'on 2 ri, Modong-myon have been changed according to the path of a traditional and commercial mode of production, respectively.

• Journal of the Korean association of regional geographers
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• v.19 no.4
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• pp.668-682
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• 2013

This study illustrates the mechanism of The Decrease of Korean population in Yanbian Korean Autonomous Prefecture (YBKAP) and some changes of regional characteristics since China's economic reforming. Due to China's Implementing market economic system, deregulating in family register system, higher mobility since establishing Sino-Korean diplomatic relations, the expansion of intermarriages and residential areas, Korean community is confronted with lower birthrate and continuous mobility of the young and women. It directly connects to a decrease in urban population and aging, causing a decline in farming production, disintegrating of Korean community, weakening the function of villagers' organization, shrinking in Korean education and leaderships. For supplementing the shorted labor, Chinese farmers from other areas flow into the YBKAP, showing some different trends, such as farming Chinesization, Chinese farmers' higher economic level than Korean, the Korean traditional paddy field transforming into dry farmland with single-crop farming and pursuing commercial production in labor management. At the moment, declining population in Korean community in rural areas means that the community could not respond the changes of farming environments appropriately and in some way it is facing with the crisis of die away from the Chinese society. It needs an unconventional support and development policies in YBKAP rural areas.

• Journal of Life Science
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• v.18 no.7
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• pp.907-911
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• 2008

Radish (Raphanus sativus L.) is one of very important crop plants in the world. It is very important to determine hybrid seed quality in the production of hybrid Brassica vegetable seeds to avoid unacceptable contamination with self-inbred (sib) seeds. The allozyme for evaluating seed purity in a commercial $F_1-hybrid$ radish cultivar is demonstrated. Three hundred sixty seeds from the male and female harvest were subsequently screened for seed purity using 27 isozyme loci. Especially, F1 hybrids of radish, Per-1 ($aa{\times}bb$), Lap-1 ($aa{\times}bb$), Est-1 ($aa{\times}bb$) were presented clear hybrid bands. Est-1 locus revealed that 15 (8.3%) seeds from the female harvest and 26 (14.4%) seeds from the male harvest were sibs. It maintains higher than average level of genetic diversity compared with their correspondent parents. Shannon's index of phenotypic diversity (I) of hybrids was the highest of all accessions (R. sativus L. cv. Daepeng, R. sativus L. cv. Backza, and their hybrids). The allozyme may lead to a better insight into the hybrid seed purity.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.166-173
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• 2010

The purpose of functional genome research is to identify biological function of useful gene and to give an agricultural value in plant biotechnology. Brassica rapa is an economic crop which recorded 1,000 billion won of domestic market and 100 million dollar of exports and it produces 2.5 million ton in 50,000 ha as a major ingredient of representative Korean food, Kimchi. Furthermore, it is very important crop economically and commercially because Korea is major seed exporter. The fact that Multinational Brassica Genome Project (MBGP) was launched and Arabidopsis thaliana, affiliated to same genus with B. rapa, has been fully sequenced activated functional genome research of B. rapa. Besides new technologies related to gene function analysis keep developing, many results are reporting every year by international research including Korea. This review paper introduces development of Chinese cabbage mutants which is a first step in functional genome research, variant phenotypes of mutants, flanking DNA analysis in B. rapa genome, gene identification, gene analysis using microarray, and representative researches.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.180-189
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• 2017

Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by global agricultural companies. Until now, GM crops have not been cultivated commercially in Korea. Commercialization of GM crops requires a compulsory assessment of environmental risk associated with the release of GM crops. This study was conducted to evaluate the frequency of pollen mediated gene flow from Bt transgenic rice (Agb0101) to japonica non-GM rice (Nakdongbyeo), indica non-GM rice (IR36), and weedy rice (R55). A total of 729,917, 596,318 and 230,635 seeds were collected from Nakdongbyeo, IR36, and R55, respectively, which were planted around Agb0101. Selection of the hybrids was determined by repeated spraying of herbicide and Cry1Ac1 immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using specific primer. The hybrids were found in all non-GM rice and out-crossing ranged from 0.0005% at IR36 to 0.0027% at Nakdongbyeo. All of hybrids were located within 1.2 m distance from the Agb0101 rice plot. The meteorological elements including rainfall and temperature during rice flowering time were found to be important factors to determine rice out-crossing rate. Consideration should be taken for many factors like the meteorological elements of field and physiological condition of crop to set up the safety management guideline to prevention of GM crops gene flow.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.171-182
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• 2018

Papaya (Carica papaya L.) is one of the crops widely planted in tropical and subtropical areas. The papaya fruit has low calories and are plentiful in vitamins A and C and in minerals. A major problem in papaya production is a plant disease caused by the papaya ringspot virus (PRSV). The first PRSV-resistant GM papaya expressing a PRSV coat protein gene was developed by USA scientists in 1992. The first commercial GM papaya cultivars derived from the event was approved by the US government in 1997. Development of transgenic papayas has been focused on vaccine production and limited agricultural traits, including insect and pathogen resistance, long shelf life, and aluminum and herbicide tolerance. Approximately 17 countries, including the USA and China, produced transgenic papayas and/or commercialized them, which provoked studies on biosafety assessment and development of GM-detection technologies. For the biosafety assessment of potential effects on human health, effects of long-term feeding to model animals have been studied in terms of toxicity and allergenicity. Studies on environmental safety assessment include influence on soil-microbial biodiversity and transfer to soil bacteria of GM selection markers. Many countries, such as Korea, the European Union, and Japan, that have strict regulations for GM crops have serious concerns about unintended introduction of GM cultivars and food commodities using unauthorized GM crops. Transgene- and/or GM event-specific molecular markers and technologies for genomics-based detection of unauthorized GM papaya have been developed and have resulted in the robust detection of GM papayas.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.347-356
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• 2018

Genetically modified (GM) crops have been increased continuously over the world and concerns about the potential risks of GM crops have also been increasing. Even though GM crops have not been cultivated commercially in Korea, it should be necessary to develop the safety assesment technology for GM crops. In this study, we investigated the influence of heading date difference on gene flow from GM to non-GM rice. In the experimental plot design, The PAC GM rice was placed in the center as a pollen donor and non-GM rice were placed in eight directions as pollen receivers. Five pollen receiver rice cultivars were Unkawng, Daebo, Saegyejinmi, Nakdong-byeo, and Ilmi which had different flowering times. A total of 266,436, 300,237, 305,223, 273,373, and 290,759 seeds were collected from Unkawng, Daebo, Saegyejinmi, Nakdong, and Ilmi, respectively, which were planted around PAC GM rice. The GM${\times}$non-GM hybrids were detected by repeated spraying of herbicide and PAT immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using PAC gene specific primer. The hybrids were found in Nakdong-byeo which had the same heading date with PAC GM rice. The hybridization rate was 0.0007% at Nakdong-byeo plot. All of GM${\times}$non-GM hybrids were located within 2 m distance from the PAC GM rice zone. The physiological elements including rice heading date were found to be important factors to determine GM?rice out crossing rate with GM rice. Consideration should be taken into for many factors like the physiological elements of field heading date of rice cultivars to set up the safety management guideline for prevention of GM rice gene flow.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.1-10
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• 2017

Weed management under organic farming systems is very problematic since organic agriculture does not allow synthetic herbicides. Bioherbicide is needed to develop for weed management in organic agriculture systems. This review covers current status and perspectives of bioherbicide development for effective nonchemical weed management in organic farming systems. Bioherbicides are products of natural origin derived from living organisms, and more specifically bacteria, fungus and plants including natural metabolites for weed control. Bioherbicides derived from microorganisms or natural molecules are currently available on the pesticide markets. Devine, Lockdown (Collego), BioMal, Camperico, Organo-Sol and Opportune were derived from bacteria, Woad Warrior, Smolder, Mygogen, Chontrol Paste, Starritor and Phoma derived from fungus, and Katoun (pelargonic acid) and Beloukha were derived from plants. Corn gluten meal products and plant essential oils products are also available for nonselective weed control in organic agriculture. Organic weed management methods may be more feasible in small scale farming and high-value crops, and bioherbicides may be applied with other weed control practices in organic farming systems.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.127-132
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• 2012

We analysed the current status of development of GM crops and national biosafety framework including legislation-related agricultural GMO in China to provide the policy for the development of global GM crops in Korea. In China, several GM crops including cotton, petunia, tomato, sweet pepper, poplar, and papaya have been approved for commercialization and they have been cultivated at more than 4 million ha. In addition, GM rice and GM maize have also obtained approval for productive testing in 2009. China will be the first country to approve GM rice for commercialization. Prior to commercialization in China, all GM crops must be approved by government authority for biosafety assessment specified by national legislation including restricted field testing, enlarged field testing, productive testing and safety certificate. According to China's legislation, agricultural GMOs have been classified by research and testing, production and processing. All GMOs must go through 3 steps of field testing (restricted, enlarged and productive). Prior to conducting each field testing, it has to be approved by government authority. It is assumed that at least one to two years will be taken for each step of field testing (total 4 to 8 years to obtain the final safety certificate) along with a large amount of budget.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.192-200
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• 2012

For the development of genetically modified plants, it is important to verify various factors which potentially affect the risk assessment as well as to establish an experimental program to produce scientific and reliable data. However, it is a time and cost consuming process to develop GM plants as well as to prepare scientific and convincible data for government's approval. Therefore, using the transgenic hot pepper tolerant to a new CMV pathotype, we attempted to suggest few methodological procedures, such as probe saturation for southern blot analysis and RT-PCR and ELISA for expression analysis, for identification and stability evaluation of inserted gene in genetically modified plant which are required for submission for approval. Ten partially overlapped probes covering full length of inserted gene were produced. We could identify that the inserted gene was stacked as a single copy as well as no partial element existed. Also, we could identify the stability of the inserted gene stacked in hot pepper using probe saturation. In the expression analysis with RT-PCR and ELISA, we also could provide the stable expression of transcript and proteins in leaves and placenta and pericarp of fruits of the CMV-resistant hot pepper.