• Journal of Life Science
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• v.25 no.10
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• pp.1091-1097
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• 2015

We have isolated and characterized an ascorbate peroxidase (APx) gene, OsAPx1 from rice. Northern and Western blot analyses indicated that at young seedling stage, OsAPx1 mRNA was expressed highly in root, shoot apical meristem (SAM) and leaf sheath than leaf. In mature plant, OsAPx1 gene expressed highly in root, stem and flower but weakly in leaf. OsAPx1 gene and protein expression level was induced in leaves inoculated with Magnaporthe oryzae (M. oryzae) and Xanthomonas oryzae pv. oryzae (Xoo). Phytohormones treatment showed that OsAPx1 was up-regulated by jasmonic acid (JA), but was down regulated by ABA and SA co-treatments with JA, resulting that they have antagonistic effect on pathogen responsive OsAPx1 expression. Phylogenetic analysis illustrated that Arabidopsis AtAPx1 has a close relationship with OsAPx1. In AtAPx1 knock out lines, the accumulation of O₂^- and H₂O₂ are all highly detected than wild type, revealing that the high concentration of exogenous H₂O₂ cause the intercellular superoxide anion and hydrogen peroxide accumulation in AtAPx1 knockout plant. These results suggested that OsAPx1 gene may be associated with the pathogen defense cascades as the mediator for balancing redox state by acting ROS scavenger and is associated with response to the pathogen defense via Jasmonic acid signaling pathway.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.89-99
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• 2007

To develop durable and stable breeding strategies far the control of rice bacterial blight (BB) disease, the near-isogenic lines (NILs) with diverse resistance genes to BB isolates were evaluated in plant at three different growth stages using four Korean ($K_1,\;K_2,\;K_3,\;K_{3a}$) and three Japanese isolates (I, II, III). The resistance of the NILs to seven BB isolates tended to increase with plant aging. At the seedling stage, the NILs with single resistance genes were mostly resistant to $K_1$ race but they showed partial or no resistance to other isolates. A NILs (IRBB5) possessing xa5 had full resistance to the four Korean isolates, illustrating that it is a useful source to give enhancement to Korean breeding program. At the maximum tillering stage, resistance of NILs to $K_2,\;K_3$, I and II isolates considerably increased while resistance to $K_1,\;K_{3a}$ and III were similar to those of seedling stage. NILs with resistance gene of Xa4, xa5 and Xa7 proved to be the most stable to BB isolates at the maximum tillering stage. At the heading stage, most resistance genes of NILs were effective against BB isolates, and xa5 showed the consistent resistance to all the BB isolates including $K_{3a}$ and III isolates, demonstrating that resistance genes of Xa4, xa5 and Xa7 can be used either alone or combined to enhance resistance to BB disease in Korea.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.71-76
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• 2015

Developed countries have set seed industry as a new growth engine, which demands strong support from the government. Multinational seed companies such as Monsanto and DuPont have made huge financial investment to secure their major roles in the global market. To spur domestic seed industry performance, Korean government laid out the foundation for developing seed industry through policy promotion in the late 2000s. In this paper, I look at the current state of the domestic and international seed market to provide information for improving the efficiency of the propulsion of the Golden Seed Project (GSP) along with its vision. The increasing size of global giant companies has been regarded to monopolize the world seed industry wherein ten renowned companies occupy 73% of the overall global market. In effect, this causes a price hike due to limited seed choices. Domestic seed market has been stuck in a range due to a sustained low agricultural production resulting in decreased seed demand and market size. Though breeding technologies for rice and vegetables are world-class, the technologies for top global crops such as cabbage, paprika, and forage are insufficient therefore professionals in this field are not easily employed. Moreover, there is a lack in appropriate infrastructure set up in the universities which adds to ineffective training of professionals. Being a key-supporting industry for agriculture, seed industry should be granted with strong and sustainable investment support from the government. In view thereof, GSP, which started in 2012, ambitions to spur researches outlined by excellent professionals in universities and seed companies aimed to drive seed export volume and quality and attain domestic seed self-sufficiency through adoption of export- and import-substitution seed types (10 varieties each) development strategies. To develop Korea's seed industry excellent achievement of GSP's goals should be drawn successfully and to do this beside development of high quality seeds, support programs for promotion of seed exports are also needed.

• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.289-296
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• 2001

The main objective of this topic is to establish strategies and to plan biotechnology researches which are related to the agricultural improvements especially focusing on the crop breeding in Korea. From 1960's to 1980's government policy had been emphasized to develope high yielding cultivars for the self sufficient supply of the staple food crops. As a result, considerable increase of rice production has been made with accumulating technology and man's powers. Recently genetically modified crops harboring useful characteristics have been developed using biotechnology and released in the developed countries. National research institutes and private companies have been developed biotechnology researches to establish competitive capabilities, however they have not been successfully used in commercialization. Therefore it is necessary to promote the practical. application by connecting molecular technology with conventional breeding. Proposed research projects are; (1) basic researches including plant genome studies, (2) developing new cultivars through gene transformation, (3) screening and producing antioxidants, secondary metabolite substances and edible vaccines. To set a government policy, both domestic and international research trends were reviewed and possibility of success based on the economic view point were discussed. The intellectual property and preservation of environment play a key role to decide the research priority. It is also necessary for us to make one step system for the distribution of research resources such as microorganisms, genes cloned, plant seeds and research informations for promoting research activities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.165-170
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• 1994

High quality rapeseed cultivars including Nojeokchae, Yeongsanyuchae Halla-yuchae and Tamrayuchae have been released and recommended as a zero erucic acid variety to Cheju farmers for 13 years, where is a major rapeseed production area in korea. However, rapeseeds produced in Cheju island in 1992 and 1993 contained 47.7% and 37.0% of erucic acid respectively resulting in poor quality oil being not adequate for edible oil. It was considered that the zero erucic acid varieties did not have an opportunity to be cultivated in Cheju island by farmers living in the Island. Thus, the new rapeseed varieties without erucic acid should be bred and recommended to the farmers of southern area of Korea as a multiple cropping crop just after rice harvest, and for large scale mechanized and labour-serving rapeseed culture. The change of rapeseed breeding goal would be desirable for fatty acid composition improvement of rapeseed to develop varieties adaptable to southern part of Korea, and to produce rapeseed oil directly used as an edible oil safely.

• Korean Journal of Breeding Science
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• v.51 no.4
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• pp.386-394
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• 2019

Rehmannia glutinosa, one of the major medicinal crops in Korea, can be classified into three types: fresh, dried and prepared Rehmannia root. In this study, the quality characteristics of prepared rehmannia root were evaluated using four different cultivars that are commonly used in the market. In making prepared rehmannia root, roots of Jihwang 1, Kokang, Togang, and Dagang were dried, soaked in rice wine, and steamed nine times. At each stage, physiochemical properties were analyzed, including yield, which is one of the most important industrial factors to consider. The yield was the highest in Togang at 23.61% and the lowest in Dagang at 21.16%. These yield values showed a highly negative correlation with the moisture content of roots. The fructose and glucose contents were increased during the 3^rd, 4^th and 5^th steaming but then decreased. The sucrose, raffinose, and stachyose content gradually decreased during the first three steaming and were not detected during the 4^th steaming. Additionally, the catalpol content was not detected after the 4^th steaming. On the contrary, the 5-hydroxymethylfurfural content was not detected in the raw root but increased during the steaming. Jihwang1 and Togang exceeded the 0.1% Korean Pharmacopoeia standard after the 5^th steaming, reaching it faster than did the other cultivars. Overall, Togang was the optimal cultivar considering the overall characteristics of its high yield and short steaming time. These results could provide useful information for the industrial use of prepared Rehmannia root based on the requirements and characteristics of each cultivar.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.61-70
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• 2019

"Jungmo2510", a rye cultivar, Secale cereal L., was developed by National Institute of Crop Science, RDA in 2015. It was developed from open pollination from within 10 rye cultivars or lines including "Chochun" in 1995. The line "SR95POP-S1-523-1-5-5-4-7-3-B-16-3-19" was selected for its excellent agronomic appearance and was placed in yield trials for two years from 2011 to 2012. The line was designated "Homil55" and was placed in regional yield trials at the four locations around Korea from 2013 to 2015, during which time the name "Jungmo2510" was given. This cultivar is an erect plant type and leaves of short and broad size with a green color, a yellow colored, medium-diameter culm, and a yellowish brown-colored, medium-size grain. The heading date of "Jungmo2510" was April 16, which were 2 days earlier than that of "Gogu". "Jungmo2510" also showed similar to winter hardiness and greater resistance to lodging compared to those of the check cultivar. Over three years, the average dry matter yield of "Jungmo2510" was 802 kg 10a^-1 , which was harvested in late April and was lower than that of the check cultivar "Gogu" (825 kg). The seed productivity of "Jungmo2510" was approximately 481 kg 10a^-1 , which was 2.4% less than that of the check. "Jungmo2510" was higher to than "Gogu" in term of protein content (9.1% and 8.0%, respectively), total digestible nutrients(TDN)(57.5% and 55.5%, respectively), and TDN yield 10a^-1(419 kg and 392 kg, respectively). This cultivar is recommended as a fall sowing crop in areas where the average daily minimum-mean temperatures are higher than -12 ℃ in January, and as a winter crop for whole-crop forage before the planting of rice or green manure around Korea.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.85-100
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• 2008

Gray leaf spot (GLS) is a serious fungal disease caused by Pyricularia oryzae Cavara, recently reported on the important turf and forage species, perennial ryegrass (Lolium perenneL.). This fungus also causes rice blast, which is usually controlled by host resistance, but durability of resistance is a problem. Few instances of GLS resistance have been reported in perennial ryegrass. However, two major QTL for GLS resistance have been detected on linkage groups 3 and 6 in an Italian x perennial ryegrass mapping population. To confirm that those QTL are still detectable in the next generation and can function in a different genetic background, a resistant segregant from this population has been crossed with an unrelated susceptible perennial clone, to form a new mapping population segregating for GLS resistance. QTL analysis has been performed in the new population, using two different ryegrass field isolates and RAPD, RFLP, and SSR marker-based linkage maps for each parent. Results indicate the previously identified QTL on linkage group 3 is still significant in the new population, with LOD and percent of phenotypic variance explained ranging from 2.0 to 3.5 and 5% to 10%, respectively. Also two QTL were detected in the susceptible parent, with similar LOD and phenotypic variance explained. Although the linkage group 6 QTL was not detected, the major QTL on linkage group 3 appears to beconfirmed. These results will add to our understanding of the genetic architecture of GLS resistance in ryegrass, which will facilitate its use in perennial ryegrass breeding programs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.298-308
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• 1988

This study was carried out to get infirmation for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in Japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effentive ripening.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.309-314
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• 1988

This study was carried out to get information for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5 days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effective ripening.