• Korean Journal of Weed Science
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• v.7 no.2
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• pp.200-207
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• 1987

This study was conducted to select and develop herbicide resistant plant through tissue culture. Growth response of seedlings and callis of various rice varieties with Echinochloa species was assessed under the treatment of various rates of butachlor [N-(butoxy methyl)-2-chloro-2', 6'-diethyl acetamide] and simetryne [2,4-bis(ethyl amino)-6-methyl thio-1,3,5-triazine]. Further, succinate dehydrogenase activity was determined in herbicide treated callus to characterize different response of plants to herbicide. Rice variety like Sangpung showed relative resistance in both callus and seedling states against butachlor, indicating maintenance of resistance. However, in the simetryne treatment, the similar response was not observed in callus and seedling state, although there was a great different response among plant materials against simetryne. Rice variety which exhibited resistance in callus and seedling states showed low succinate dehydrogenase inhibition index. Succinate dehydrogenase inhibition index can be used as an important marker characters to differentiate varietal response of plant to herbicide. Rice plant was differentiated from butachlor and simetryne tolerant callus treated at $2.5{\times}10^{-5}$ M is growing under the growth chamber and can be used for resistant source.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.172-178
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• 2010

This study was carried out to investigate abiotic and biotic environmental factors affecting homoharringtonine (HHT) contents of Cephalotaxus koreana, whereby, to provide basic information of high value-added industry production of HHT as a promising anti-cancer agent. For correlation between abiotic environmental factors (soil moisture, soil pH, habitat density and temperature) and HHT contents, the contents were highly correlated with soil moisture (0.77) and soil pH (-0.68). For multiple regression analysis of relationship between abiotic environmental factors (soil moisture and soil pH) and HHT contents, soil moisture appeared to be strongly affecting the contents relatively due to being significant at only its regression coefficient ($26.48^{***}$). For the effect of biotic environmental factors (damage index) affecting HHT contents, the contents was quadratic with equation of $H=278.23+1242D-398.87D^2$, also, damage index had strong effect on the contents. Finally, for the result of the most influencing an environmental factor on HHT contents, both damage index and soil moisture were suitable in second polynomial regression, also, damage index ($R^2=0.73^{***}$) was turned out to be more influencing factor than soil moisture ($R^2=0.67^{**}$) on HHT contents relatively. Therefore, we predict that HHT contents in the trees of Cephalotaxus koreana is produced as a chemical defense mechanism triggered by a stress-related damage of fungi or insects.

• Journal of Plant Biotechnology
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• v.49 no.1
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• pp.39-45
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• 2022

Conserved domains are defined as recurring units in molecular evolution and are commonly used to interpret the molecular function and biochemical structure of proteins. Herein, the ADP-glucose pyrophosphorylase (AGPase) amino acid sequences of three species of the Ipomoea genus [Ipomoea trifida, I. triloba, and I. batatas (L.) Lam. (sweetpotato)] were identified to investigate their physicochemical and biochemical characteristics. The molecular weight, isoelectric point, instability index, and grand average of hyropathy markedly differed among the three species. The aliphatic index values of sweetpotato AGPase proteins were higher in the small subunit than in the large subunit. The AGPase proteins from sweetpotato were found to contain an LbH_G1P_AT_C domain in the C-terminal region and various domains (NTP_transferase, ADP_Glucose_PP, or Glyco_tranf_GTA) in the N-terminal region. Conversely, most of its two relatives (I. trifida and I. triloba) were found to only contain the NTP_transferase domain in the N-terminal region. These findings suggested that these conserved domains were species-specific and related to the subunit types of AGPase proteins. The study may enable research on the AGPase-related specific characteristics of sweetpotatoes that do not exist in the other two species, such as starch metabolism and tuberization mechanism.

• Research in Plant Disease
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• v.29 no.2
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• pp.137-144
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• 2023

Exserohilum turcicum is a fungus that causes northern corn leaf blight (NCLB) and has deleterious effects on maize production globally. Therefore, it is prudent to mitigate the effects of NCLB using genetic diversity. The objective of this research was to assess the severity of NCLB disease on the growth and yield of various maize genotypes. A randomized complete block design field experiment, replicated three times, was conducted to evaluate the effect of E. turcicum on 10 maize hybrids. Percent disease index, plant height, and leaf area were recorded at the silk stage. Cob weight, grain fresh weight, and grain yields were determined at harvest maturity. All measured parameters were significantly different (P<0.05) between the maize hybrids. Of the 10 genotypes, four (PAN 4R-528R, PAN 4R-728BR, PAN 3R-724BR, and P1788BR) were susceptible, five (DKC74-74BR, PAN 5R-582R, PAN 5R-890R, PAN 5R-854R, and PAN 5R-590R) were moderately susceptible, and one (DKC80-40BR) was moderately resistant. DKC80-40BR exhibited greater cob weight, while DKC74-74BR was superior in all other plant growth and yield components. Interestingly, although not significant (P>0.05) and high, maize growth and yield parameters had negative correlations with disease incidence, except for grain fresh weight. Therefore, DKC80-40BR may be selected for cultivation in areas prone to NCLB to reduce maize susceptibility to the disease, while DKC74-74BR may improve crop performance. These hybrids could be considered as potential sources of resistance or tolerance to NCLB for further validation by plant breeders.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.162-181
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• 2011

The purpose of this study was to analyze the current status of both exotic and naturalized plants in the designated Cultural Preservation Area located in Seongju-gun, Gyeongsangbuk-do in order to identify traditional cultural places and to provide basic information to prepare a conservation strategy. The vascular plant species was identified as having 114 taxa: 50 families, 93 genera, 94 species, 16 varieties and 4 forms in King Sejong's Prince Taesil. Among them are 15 taxa of the exotic plant species and 16 taxa of naturalized plant species, which resulted in 14.04% of the Naturalization Rate and 5.90% of the Urbanization Index. The vascular plant species was identified as 68 taxa: 40 families, 64 genus, 57 species, 8 varieties and 4 forms in the Seongju Hyanggyo. Among them, the exotic plants recorded 17 taxa with 30 taxa of naturalized plants. The Naturalization Rate was 44.12% and Urbanization Index was 11.07%. The Seongbaksup, which was a grove outside of the Seongju Fortress recorded 61 taxa: 34 families, 58 genera, 55 species, 5 varieties and 1 form. Among them, the exotic plant species consisted of 10 taxa with 17 taxa of naturalized plants, with a 27.87% Naturalization Rate and a 6.27% Urbanization Index. The vascular plant species was recorded as 230 taxa: 92 families, 183 genus, 182 species, 1 subspecies, 32 varieties and 14 forms in Hangae Village. Among them, exotic plants consist of 28 taxa with 85 naturalized plant species, with a Naturalization Rate of 37.12% and Urbanization Index of 31.37%. The vascular plant species in the Seongsan Ancient Tomb is recorded as having 131 taxa: 55 families, 107 genus, 106 species 19 varieties and 6 forms. Among them, exotic plants consist of 18 classifications, and naturalized plants consist of 22 classifications with a Naturalization Rate of 16.79% and an Urbanization Index of 8.12%. The Seongju Hangyo recorded the highest Naturalization Rate among all surveyed sites in Hangae Village. All five of these surveyed sites will require a management plan to eradicate both exotic and naturalized plant species. Hangae Village especially needs to prepare a management plan. The invasion of ragweed in Seongju Hanggyo and Hangae Village, which is one of the most invasive plant species to disturb the ecosystem, is in need of management to eradicate it.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.127-132
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• 1985

In this study, the competitive development of leaf in Amaranthus and Chenopodium were invesitgated by the complemented plastochron index. The value of PI for Amaranthus was not varied with competional ratios, while for Chenopodium it was varied. Namely in Chenopodium, the plastochron 1 was increased as competitional combinations, the plastochron 2 was decreased. These results indicated Amaranthus had advantage in competition over Chenopodium. It is surmised that these results were exhibited differences in photosynthetic pathway between Amaranthus (C4 plant) and Chenopodium (C3 plant). The linear patterns were clearly demonstrated by the differences in leaf arrangement between Amaranthus (alternate type) and Chenopodium (opposite type). From these resultss, use of plastochron seems to a useful means of evaluating plat response to various environments.

• Resources Recycling
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• v.26 no.6
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• pp.10-19
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• 2017

It is studied the effect of crystal structure of domestic High-Ca limestones using absorbent for desulfurization on the grinding characteristics and dissolution rates in wet flue gas desulfurization process of domestic coal fired power plant. It compared the crystal structure, grinding work index and dissolution rates with 4 Limestones from Jecheon-Danyang with different crystal structure, and we found that grinding work index differ in crystal size and crystal structure of limestones : The lower the value of the grinding work index is, the higher the dissolution rates of limestones. Confirmed that we have important indicators of grinding characteristics for crystal structure with CaO content of limestones.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.103-112
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• 2001

The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.

• Research in Plant Disease
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• v.18 no.4
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• pp.381-386
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• 2012

Nematode fauna in Dokdo island was investigated for two years between 2008 and 2009. Population density and biomass were $239,500m^2$ (26,000-836,000) and $103.9mg/m^2$ (3.0-388.6), respectively. Total of 31 species of nematodes were identified : Acrobeloides is the most important genus with prominence value (PV) of 117.8, followed by Rhabditidae (PV = 81.9), Prismatolaimus (PV = 39.0), and Aphelenchoides (PV = 31.4). Among feeding group, bacteriovorus nematode composed 77% of density and 62% of biomass followed by plant-parasitic and fungivorus nematodes. A species of Pratylenchus having distinctive tail terminus is under study as a new species. Biological indices, Shannon and Wiener index (2.46), Simpson's diversity index (0.86), Species evenness (0.73), Species richness (1.30) indicate that nematode fauna in Dokdo island is diverse and unique. This study may give a general idea of nematode fauna at the Dokdo island.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.130-133
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• 2001

The purpose of this study was to investigate the decreased ratio of growth and yield by delayed seeding and flowering because drought of spring season often cause to delay seeding and sprout emergence. Equation of linear regression, y=-11.914x＋818.61 ($R^2$=0.916) and y=-16.96lx＋913.98 ($R^2$=-0.885) were derived from relationship between sowing date and yield of leading variety, Yangbaeckkae in 1999 and 2000, respectively. Yield was decreased by 7, 24, 40, 57, 74%, respectively, according as sowing date was delayed more 5, 15, 26, 36, 46 days than May 15, standard sowing date under the culture mulched with black P.E. film. Number of capsules per plant and length of stem bearing capsule were greatly decreased, while plant height, stem diameter, and day to flowering were affected little by delayed seeding date. Equation of linear regression, y=-0.7081x＋41.04 ($R^2$=0.861) was derived from relationship between flowering date and yield of 33 accessions. Yield was decreased by 7.7, 8.3, 9.2, 10.1, 11.2%, respectively, according as flowering date was delayed more 1, 2, 3, 4, 5 days than July 3, normal flowering date of Yangbaeckkae when it was sown on May 15, and the more flowering date was delayed, the more yield was decreased. Number of capsules per plant and length of stem bearing capsules were greatly decreased, but plant height and harvest index were decreased little by delay of flowering date