• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.316-321
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• 2003

Analysis of breeding gains in grain yield has been intensively conducted in wheat, barley, oat, maize, and soybean. Such information is limited in rice. The objective of this study was to compare the breeding gains and cultural gains contributed to yield gains of Korean rice varieties since early 1900s. Two sets of yield data were used for analysis; the historical yield data of 1908 for old japonica cultivars, and present yield data in the years from 1996 to 1998 for the six cultivars, consisting of previous two old cultivars and four contemporary cultivars. The old cultivars were two native cultivars, Jodongi and Damageum, while contemporary cultivars were two premium quality japonica cultivars, Hwaseongbyeo and Dongjinbyeo, and two Tongil-type cultivars, high yielding cultivars developed from indica/japonica hybridization, Milyang23 and Dasanbyeo. The yield differences of old cultivars between the experiments in 1908 and the experiments from 1996 to 1998 were estimated as cultural gains (1.84 tons $\textrm{ha}^{-1}$) due to the improvement of cultivation technology. Yield differences between the old cultivars and contemporary cultivars were considered total yield gains during the periods. These were 2.51 tons $\textrm{ha}^{-1}$ for japonica cultivars and 3.81 tons $\textrm{ha}^{-1}$ for Tongil-type cultivars. From these data, the genetic gain of 0.67 tons $\textrm{ha}^{-1}$ and 1.97 tons $\textrm{ha}^{-1}$ were estimated for japonica cultivars and Tongil-type cultivars respectively. The ratio between cultural gain and genetic gain appeared to be 2.7:1 for japonica cultivars and 1:1 for Tongil-type cultivars. This analysis clearly showed the higher genetic contribution in Tongil-type cultivars than in japonica cultivars, suggesting a guideline to be used when planning new yield improvement programs. Additional implication has emerged when a better yield response to modem cultivation technology was found in one of the old cultivars, suggesting the combined improvement between breeding and cultural improvement is necessary for attaining the maximum yield capacity of a crop.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.347-357
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• 2019

This study evaluated the raw materials for spawning Perenniporia fraxinea, to eliminate urushiol. The growth rates of spawns on grains of millet, brown rice, and wheat were 4.92±0.05, 2.20±0.03, and 1.93±0.03 mm/day, respectively, and the laccase activity was 0.86±0.02, 0.04±0.01, and 0.01±0.00 U/mL, respectively. These observations revealed millet as the most appropriate grain for spawn production in terms of growth rate and enzyme activity. Inoculation of lacquer tree (Rhus verniciflua Stokes) stem bark with millet spawns of P. fraxinea resulted in a reduction of its urushiol contents, up to 86.6% on the third day and up to 98.5% on the seventh day. The optimal period of cultivation to eliminate urushiol was three days with 68% of residual flavonoids and 42% of phenolic components. When compared to the product cultivated from liquid spawn, the millet spawn reduced the cultivation period from 10 days to 3 days for eliminating urushiol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.188-191
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• 1985

A thermophilic and cellulolytic bacterium, Herpetosiphon geysericola CUM 317 isolated from the compost, produced ${\alpha}-amylase,\;{\beta}-amylase$, and glucoamylase. Mutual relationships on the production of the three amylases were studied by changing the cultivation conditions. ${\alpha}-Amylase$ and glucoamylase were produced highly after 40 hrs on wheat bran medium at $50^{\circ}C$ and after 30 hrs on liquid medium at $40^{\circ}C$, though ${\beta}-amylase$ was produced best at 10 hrs of initial cultivation phase. The production of the amylases was generally repressed by the addition of carbon sources in liquid medium containing polypeptone. ${\alpha}-Amylase$ production was enhanced relatively by the addition of cupric sulfate in the liquid medium, ${\beta}-amylase$ was enhanced by cadmium sulfate, and glucoamylase was enhanced by calcium chloride.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.145-145
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• 2022

South Korea greenhouse gas emissions have increased year by year, resulting in a total emission of 727.6 million tons of CO₂ eq in 2018, a 2.5% increase compared to 2017. Among them, the agricultural sector emitted 21.2 million tons of CO₂ eq., accounting for 2.9% of the total. Among the greenhouse gases emitted from the agricultural sector, a particularly problematic is methane gas emitted from rice paddies. Methane is one of the important greenhouse gases with a global warming potential (GWP) that is about 21 times higher than that of carbon dioxide due to its high infrared absorption capacity despite its relatively short remaining atmospheric period. Since the pattern of methane generation varies depending on the rice variety and ecological type, research related to this is necessary for accurate emission calculation and development of reduction technology. Accordingly, a study was conducted to find out the changes in greenhouse gas emission according to rice varieties and ecology types. As for the rice eco-type cultivar, early maturing cultivar (Haedamssal) and medium-late rice cultivar (Saeilmi) were used. Haedamssal was transplanted on May 25 and June 25, and Saeilmi was transplanted on June 10 and June 25. The amount of methane generated according to the growing day showed a tendency to increase as the planting period was earlier. The difference between varieties was that Haedamssal showed higher methane production than Saeilmi. The total CH₄ flux in the saeilmi was 18.7 kg·h^-1(Jun 10 transplanting), 12.4 kg·h^-1(Jun 25 transplanting) during rice cultivation. Lower methane emission was observed in Saeilmi than in Haedam rice. In addition, the earlier the planting period, the higher the methane emission. This study is the result of the first year of research, and it is planned to investigate the amount of greenhouse gas emission between double cropping and single cropping using wheat cultivation after harvest for each ecological type.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.106-114
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• 2024

Fusarium head blight (FHB), predominantly caused by Fusarium graminearum and F. asiaticum, is a significant fungal disease impacting small-grain cereals. The absence of highly resistant cultivars underscores the need for vigilant FHB surveillance to mitigate its detrimental effects. In 2023, a notable FHB outbreak occurred in the southern region of Korea. We assessed FHB disease severity by quantifying infected spikelets and grains. Isolating fungal pathogens from infected samples often encounters interference from various microorganisms. We developed a cost-effective, selective medium, named BGT (Burkholderia glumae Toxoflavin) medium, utilizing B. glumae, which is primarily known for causing bacterial panicle blight in rice. This medium exhibited selective growth properties, predominantly supporting Fusarium spp., while substantially inhibiting the growth of other fungi. Using the BGT medium, we isolated F. graminearum and F. asiaticum from infected wheat and barley samples across Korea. To further streamline the process, we used a direct PCR approach to amplify the translation elongation factor 1-α (TEF-1α) region without a separate genomic DNA extraction step. Phylogenetic analysis of the TEF-1α region revealed that the majority of the isolates were identified as F. asiaticum. Our results demonstrate that BGT medium is an effective tool for FHB diagnosis and Fusarium strain isolation.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.311-319
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• 1997

These studies were carried out to develop an artificial cultivation method. The diameter and thickness of pileus ranged $1.5{\sim}7.0\;cm$ and $0.8{\sim}3.0\;cm$, respectively. The diameters of stipe were $1.2{\sim}2.5\;cm$ and the lengthes were $4.5{\sim}9.0\;cm$. The spore fingerprint was white. The sizes were spore $10.8{\sim}12.2{\times}4.35{\sim}5.65\;{\mu}m$, basidia $50.0{\sim}59.2{\times}7.4{\sim}7.8\;{\mu}m$, nalsistidia $21.75{\sim}28.7{\times}4.8{\sim}6.1\;{\mu}m$, pileus hymenium cell $50.6{\sim}66.0{\times}4.4{\sim}6.7\;{\mu}m$, and stipe hymenium cell $28.6{\sim}33.0{\times}5.5{\sim}6.6\;{\mu}m$. The thirty percent mixture of rice and wheat bran into sawdust gives the high density of mycelia and the good development of fruiting structure. The optimum water contents of sawdust substrates were $60{\sim}65%$ in which condition the mycelium grows well and gives high density. In PP bottle cultivation, the first fruiting period was $6{\sim}8$ days earlier in nonscratching samples than scratching ones, but the quantity of fruiting body was higher in scratching samples than nonscratching ones. In the case of PP bag cultivation, the first fruiting was 10 days faster, and the quantity of fruiting bodies was 30% higher in samples with 30% wheat bran than those with rice bran. The fleshiness of stipe was $2{\sim}3$ times harder than that of pileus.

• Korean Journal of Weed Science
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• v.2 no.2
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• pp.152-159
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• 1982

To investigate the effect of isoproturon (N,N-dimethyl-N-4-isopropyl phenyl urea) on weed-killing, crop injury and yield of barley, several experiments were conducted by application time, dosage, cultivars and soil texture. For the effective control of weeds the optimum application time was foliage application after winter. Alopecurus aequalis SOBOL was effectively controlled when isoproturon should be applied at three to four leaf-stage and most annual broad-leave weeds emerged through winter and spring could be controlled when applied even at five to six leaf-stage. But among the broad-leave weeds Vicia amoena Fisch. was resistant to isoproturn. The optimum application rate of isoproturon was 240g-300g/10a (prod.). Among 11 cultivars of barley and wheat, phytotoxicity of Olmil, Jokwang and Rye was slighter than that of the other cultivars when isoproturon was treated by foliage application after winter. At the time of foliage application after winter, the variation of phytotoxicity and effectiveness was a little despite the difference of soil texture and the grain yield of barley was higher in the plots treated 240-300g/10a than in other treated plots.

• Journal of Mushroom
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• v.8 no.1
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• pp.37-40
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• 2010

This study was carried out to develop the best medium of new oyster mushroom for bottle culture. The new oyster mushroom cv. Miso is a Pleurotus ostreatus developed at the Chungnam Agricultural Research & Extension Services. For the bottle culture media, poplar sawdust+beet pulp+cottonseed meal (5:3:2), poplar sawdust+wheat husk meal (8:2), poplar sawdust+beet pulp+cottonseed meal (6:2:2), poplar sawdust+beet pulp+cottonseed meal (4:4:2), and poplar sawdust+beet pulp+wheat husk meal (7:1:2) were used in 850cc PP bottle. The pH was 5~6 and the C/N ratio 19.7~28.3 in bottle culture media. The time of pinhead formation was 5 to 6 days. For the fruiting body formation after inoculation took 29~31 days. The yield of fruiting body of poplar sawdust+beet pulp+wheat husk meal (7:1:2) medium was the highest at 110.4g/bottle compared to other media. Therefore, such cultivation medium would be appropriate for the commercial production of bottle culture in the new oyster mushroom 'Miso'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.144-149
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• 2008

This study aims to understand the growth and changes of nutritional composition in five winter forage crops including barley, wheat, oat, rye and triticale. In Korea, the winter-season cultivation of the crops could enhance land use efficiency and improve the global competitiveness of domestic livestock industry by providing high quality forage. Total content of crude protein in plants decreased after heading. Leaves and spikes had high crude protein while stem showed the lowest with less than 7%. Contents of Acid Detergent Fiber (ADF) in plants decreased with time after heading. Stem showed much greater content of ADF than leaves and spikes. There was linear relationship between ADF contents and ratios of stem weight and total weight. Contents of Neutral Detergent Fiber (NDF) also decreased with time after heading. Stem contained much higher NDF than leaves and spikes. There was a linear relationship between NDF contents and ratios of stem weight and total weight. Relative Feed Value (RFV) increased with maturing of spikes after heading in barley, wheat, oat and triticale. There was a negative relationship between Relative feed value and ratios of stem weight and total weight.

• Journal of People, Plants, and Environment
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• v.24 no.6
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• pp.609-617
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• 2021

Background and objective: The nanobubbles remain stable in water, and it increased dissolved oxygen (DO) in the water that promotes the seed germination and the plant growth. We evaluated the seed germination and growth of sprouts (radish, wheat, and barley) and leafy vegetables (red mustard and pak choi) when irrigated with various DO of nanobubble water (NB). Methods: The oxygen NB was generated by surface friction and treated in 4 levels: NB 0% (control, DO 9.21 mg·L^-1), NB 20% (DO 15.40 mg·L^-1), NB 33% (DO 20.93 mg·L^-1), and NB 100% (DO 39.29 mg·L^-1). Results: The root length of radish and wheat increased more in NB 33% than the control plot. The fresh weight increased in NB 33% compared to the control plot in radish and wheat, and both fresh and dry weight increased more in NB 20%, NB 33%, and NB 100% than the control plot of barley. The leaf length and width of red mustard decreased more in NB 33% and NB 100% than the control plot and NB 20%, which indicated the leaf compactness. The fresh and dry weight of shoot and root increased more in NB 100% than the control plot in red mustard. In pak choi, the shoot fresh weight increased more in NB 100% than the control plot. In leafy vegetables, the germination rate of red mustard in NB 100% was higher than the control plot, however, it was not significantly different between oxygen NB plots in sprout vegetables. Conclusion: The results showed that the root growth and biomass increased after applying NB 33% in sprout vegetables. The leaf growth properties as the number of leaves and leaf size were not significantly different or decreased in NB treatments compared to control plots, but NB 100% (DO 39.29 mg·L^-1) effectively increased the root growth and plant biomass in leafy vegetables.