• 한국잠사곤충학회지
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• 제53권1호
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• pp.1-5
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• 2015

갈색거저리의 산업 활용도가 높아짐에 따라, 효율적인 실내 대량사육 시스템의 확립이 더욱 중요하게 인식되고 있다. 본 연구는 대량사육을 위해 다양한 범위의 온도, 광주기, 사육밀도에서 갈색거저리의 생리적 특성을 알아보고자 수행되었다. 갈색거저리 알은 $17.5{\sim}27.5^{\circ}C$에서 70% 이상의 부화율을 나타냈고, 부화기간은 $25{\sim}35^{\circ}C$에서 5~7 일로 조사되었다. 결과적으로, 부화율과 산란 전 기간(egg periods)을 고려했을 때, 대량사육을 위해 적절한 실내온도는 $25{\sim}27.5^{\circ}C$였다. 다양한 온도 조건하에서 대량사육 시스템에서 유충의 발육기간은 개별사육 시스템에서 보다 더 짧았다. 번데기 무게는 $20^{\circ}C$와 $25^{\circ}C$를 제외한 대량사육 시스템에서 좀 더 높게 관찰되었다. 수요 탄력성과 생산중량을 고려했을 때, 가장 효과적인 조건은 $25^{\circ}C$에서 대량사육한 실험군이었다. 14L : 10D의 광주기 조건에서 157.35일로 가장 짧은 유충기간을 나타냈다.

• 한국가축번식학회지
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• 제21권4호
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• pp.411-421
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• 1997

A survey was carried out to investigate the symptoms and occurance of reproductive disorder in Hanwoo(Korean native cattle). Data of the reproductive disorder of 561 heads from 28 farm households have been collected from Dec. '95 to Nov. '96 and analyzed calving no, nutritional body condition and housing forms. The results obtained are summarized as follows: 1. The incidence of reproductive disorder was 20.1% and the major common symptoms were repeat breeding(39.8%), anestrous(31.0%), nymphomania(10.6%) and subestrous(8.9%). 2. The incidence of reproductive disorder according to the calving no., that of heifer, calved one to two calving no. and over three calving no. were 20.6%, 13.9% and 34.5%, respectively. 3. Reproductive disorder incidence according to the nutritional body condition was 18.3%, 14.6% and 48.7% at body condition score(BCS) less than 2.0, 2.5 to 3.0 and over than 3.5, respectively. At BCS over 3.0, the symptoms of common reproductive disorder were repeat breeding(17.6%), anestrous(12.2%), nymphomania(10.8%) and subestrous(2.7%). 4. The incidence of reproductive disorder according to the housing form 15.8% and 34.6% for group feeding in open house and individual stanchion feeding in stall, respectively. In group feeding, reproductive disorder incidence of cows raised in space of more than 9.9$m^2$ per head was 14.1%, while that of cows raised less than 9.9$m^2$ per head was 18.2%. And incidence of repeat breeding, aneestrous and subestrous was more frequent in individual stanchion feeding than group feeding.

• 한국작물학회지
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• 제53권4호
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• pp.421-426
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• 2008

Freshly harvested seed of Chinese milk vetch (Astragalus sinicus L.; CMV) was strongly dormant because of hardseedness. Seeds of freshly harvested germinated only 8% while clipping the seed coat completely overcome the innate dormancy, which indicates inhibition of germination of the seed is mainly due to seed coat (87%). The dormant (intact) hard seeds did not imbibe water whereas the non-dormant (clipped) seeds took up rapidly. In natural environment condition, the hard seed coat dormancy was broken only after 5 months after seed harvest. To break such a strong seed coat dormancy, the chemical and heat treatments were effective. Concentrated sulfuric acid was more effective than dry heat and hot water treatments. Hot water treatment improved germination but the germination percentage was less than 41%. Treatments increased germination due to its effect on the seed coat integrity. A scanning electron microscope reveled that disruption of seed coat layers and subsequent development of numerous crack in the hilum region of the seed and on the seed coat surface of concentrated sulfuric acid treatment and formation of cracks in the dry heat treatments, respectively, were observed in the seed coat surface, which served as water entry points.

• ALGAE
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• 제35권3호
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• pp.253-262
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• 2020

Haematococcus pluvialis is a commercial microalga that can produce high quantities of astaxanthin. Under induced conditions, some important changes in the subcellular structures related to astaxanthin accumulation were observable. For example, a large number of astaxanthin granules, oil structures and starch granules appeared in the thick-walled cells; Astaxanthin granules gradually dissolved into the oil structures and spread throughout the entire cell with the fusion and diffusion process of oil structures during the middle and late stages of induction; The plastoglobules were closed to the newly formed structures, and some plastoglobules would abnormally increase in size under stress. Based on observations of cell damage, the degradation of membrane structures, such as chloroplasts, was found to be the primary form of damage during the early stage of induction. During the middle stage of induction, some transparent holes were exposed in the dissolving astaxanthin granules in the cytoplasm. In thick-walled cells, these transparent holes were covered by oil substances dissolving astaxanthin, thereby avoiding further damage to cells. Given the relatively few oil structures, in non-thick-walled cells, the transparent holes expanded to form multiple transparent areas, eventually resulting in the rupture and death of cells. These results suggested that the high level of synthesis and the wide range diffusion of oil explained the expansion of astaxanthin in H. pluvialis.

• 한국작물학회지
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• 제53권3호
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• pp.326-332
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• 2008

영남평야지 조기재배시 국내 육성된 고품질 조생종 품종들의 품질에 미치는 영향을 살펴본 결과를 요약하면 아래와 같다. 1. 공시품종들의 평균 출수기는 7월 22일로 8월 하순에서 9월 상순사이에 수확이 가능한 것으로 판단되었고, 공시품종들의 평균 수당립수, 등숙율 및 수량에서 품종간 유의한 차이가 있었으며, 운광벼가 수량이 529 kg/10a로 가장 많았다. 2. 수확시기별 현미 품위를 조사한 결과 동할미 발생을 줄이고 현미 정립율을 높이기 위해서는 출수 후 40일경에 수확하는 것이 정립은 8월25일$\sim$ 9월1일 사이 수확하는 것이 가장 높았으며, 수확시기가 늦어질수록 미숙립의 발생은 감소하고 동할립의 발생은 증가하였다. 백미 완전미는 중화벼와 고운벼가 72.2%와 71.0%로 높았으나 싸라기 발생이 높았으며, 운광벼와 오대벼는 분상질의 발생이 많았다. 3. 운광벼와 오대벼는 백미 단백질 함량은 6.4%로 낮았으며, 식미관능검정의 총평이 각0.6 및 0.5로 밥맛이 양호하였다.

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2180-2189
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• 2017

Psychrophilic phytases suitable for aquaculture are rare. In this study, a phytase of the histidine acid phosphatase (HAP) family was identified in Morchella importuna, a psychrophilic mushroom. The phytase showed 38% identity with Aspergillus niger PhyB, which was the closest hit. The M. importuna phytase was overexpressed in Pichia pastoris, purified, and characterized. The phytase had an optimum temperature at $25^{\circ}C$, which is the lowest among all the known phytases to our best knowledge. The optimum pH (6.5) is higher than most of the known HAP phytases, which is fit for the weak acidic condition in fish gut. At the optimum pH and temperature, MiPhyA showed the maximum activity level ($2,384.6{\pm}90.4{\mu}mol{\cdot}min^{-1}{\cdot}mg^{-1}$, suggesting that the enzyme possesses a higher activity level over many known phytases at low temperatures. The phytate-degrading efficacy was tested on three common feed materials (soybean meal/rapeseed meal/corn meal) and was compared with the well-known phytases of Escherichia coli and A. niger. When using the same amount of activity units, MiPhyA could yield at least $3{\times}$ more inorganic phosphate than the two reference phytases. When using the same weight of protein, MiPhyA could yield at least $5{\times}$ more inorganic phosphate than the other two. Since it could degrade phytate in feed materials efficiently under low temperature and weak acidic conditions, which are common for aquacultural application, MiPhyA might be a promising candidate as a feed additive enzyme.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.202-202
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• 2022

Recently days, soybean production in paddy field is increasing, from 4,422 ha in 2016 to 10,658 ha in 2021 in Korea. It is easy for Phytophthora stem and root rot (PSR) occurring in paddy field condition, when it is poorly drained soils with a high clay content, and temporary flooding and ponding. Therefore PSR resistant soybean cultivar is required. The objective of this study is to identify QTL region and candidate genes relating to PSR resistance of the race in main soybean cultivation area in Korea. 210 soybean materials including cultivars and germplasm were used for inoculation and genome-wide association study (GWAS). Inoculation was conducted using stem-scar method with 2 replications in 2-year for the race 3053 from Kimje and 3617 from Andong. 210 materials were genotyped with Soya SNP 180K chip, and structure analysis and association mapping were conducted with QTLMAX V2. The results of inoculation showed that survival ratio ranged from 0% to 96.7% and mean 9.7% for 3053 and ranged from 0% to 100% and mean 7.6% for 3617. Structure analysis showed linkage disequillibrium (LD) was decayed below r²=0.5 at 335kb of SNP distance. Significant SNPs (LOD>7.0) were identified in Chr 1, 2, 3, 4, 5, 11, 14, 15 for 3053 and Chr 1, 2, 3, 7, 10, 14 for 3617. Especially, LD blocks (AX-90455181;15,056,628bp~AX-90475572;15,298,872bp) in Chr 2 for 3053 and 3067 were duplicated. 29 genes were identified on these genetic regions including Glyma.02gl47000 relating to ribosome recycling factor and defense response to fungus in Soybase.

• Fisheries and Aquatic Sciences
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• 제9권1호
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• pp.7-13
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• 2006

Using biochemical methods, we determined the potential of local female shrimp populations as breeding stock to select the best adult prawns for improving larval production. As condition indexes, we selected total RNA, DNA, their ratio, and trypsin activity. The DNA content in the pleopods of each local population was similar, i.e., between $0.90{\pm}0.06\;and\;1.02{\pm}0.04(SE){\mu}g/mg$. In comparison, the RNA contents differed markedly between $2.00{\pm}0.09$ and $0.96{\pm}0.08\;{\mu}g/mg$. Therefore, the RNA/DNA (R/D) ratio in the pleopod could be used as a condition index because it represents a biochemical characteristic of the population. The mean pleopodal R/D ratio of the Goheung population was the highest at $2.52{\pm}0.19$, which indicated the best condition. Trypsin activity was influenced little by shrimp condition and more by the amount of food ingested. The gonadosomatic index (GSI) and R/D ratio in the gonads provided offsetting information about the instantaneous gonad maturity. The Goheung population had the highest instantaneous GSI, despite some spawning. Based on the condition indexes and time of gonad maturation, the Goheung shrimp population is suitable for use as breeding stock.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.205-205
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• 2022

Sorghum (Sorghum bicolor L.) is a major cereal grain crop of the world and It can be cultivated under high temperature and dry condition with high adaptability to the adverse environment. It is usually eaten with rice in korea and most of domestic sorghum cultivars have been developed by pure line selection and cross breeding. In prior studies, Hybrid cultivar (F1 seed) was known to improve 30-40% in yield and resist to disease and pest than pure line varieties due to hybrid vigor. Therefore, study on the hybrid sorghum is continuously necessary. In korea, hybrid sorghum cultivar have been developed, so we need to find methods seed production technology for supply and commercialization of hybrid seed cultivar. Female inbred line(A-line) and male inbred line(R-line) are needed for hybrid seed production. This study was carried out to investigate growth characteristics and yield of hybrid sorghum according to the seedling period and planting rate between female inbred line(YSA1) and male inbred line (Sodamchal, Miryang 19). When the flowering period of two inbred groups in the process of hybrid seed production is coincides, hybrid seed production is increase. The female inbred line and male inbred lines were cultivated at Daegu in 2021. Two inbred lines were sown at intervals of 3 days and 7days and were evaluated flowering period. As a result, the flowering period of the female inbred line and male inbred lines were matched at the 7days interval. To find out optimal planting rate, two inbred lines were cultivated under different plating rate (4:2, 5:2, 6:2). Yield of YSA1/Sodamchal(F1) was the highest 130(kg/10a) in the 4:2 ratio and yield of YSA1/Miryang 19 was the highest quantity of 139(kg/10a) in the 6:2 ratio. The results of this study could be helpful for hybrid Sorghum seeds production.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.104-104
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• 2017

Sorghum (Sorghum bicolor (L.) Moench.) is one of the most important crops for human and animal nutrition. Nonetheless, sorghum has a cyanogenic glucoside compound which can be degraded into hydrogen cyanide, toxic to humans and animals even with tiny amount. In consequence, breeding materials with a low cyanide level has been a top priority in sorghum breeding programs. To fulfill our long-term goal, we are screening sorghum accessions with low cyanide level, which would be an important breeding material for food safety. We collected seeds of various sorghum accessions and analyzed relevant metabolites to find useful breeding materials of sorghum accessions containing low cyanide. Fourteen wild relatives were obtained from the University of Georgia in US, a reference accession BTx623, and three local varieties from National Agrobiodiversity Center of Rural Development Administration in Korea, and one wild species from the Wild Plant Resources Seed Bank of Korea University in Korea. Sorghum plants were grown in plastic greenhouse under natural conditions. After growing, leaf samples were harvested at different developmental stages: seedling phase, vegetative phase (right before flowering), and reproductive phase (ripening). Using collected samples, quantification analysis were performed by an HPLC system for three metabolites (dhurrin, 4-hydroxybenzaldehyde, and 4-hydroxyphenylacetic acid) in sorghum plants. Prior to metabolome analysis, specific experimental condition for HPLC system was set to be able to separate three metabolites simultaneously. Under this condition, these metabolites were quantified in each accession by HPLC system. We observed that the metabolite contents were changed differently by developmental stages and accessions. We clustered these results into five groups as patterns of their contents by developmental stages. Most of accessions showed that 4-hydroxybenzaldehyde content was very high at seedling stage and decreased rapidly at vegetative phase. Interestingly, the patterns of dhurrin content were very different among clusters. However, 4-hydroxyphenylacetic acid content was maintained at low levels by developmental stages in most accessions. The results would demonstrate how dhurrin and alternative degradation pathways are differentiated in each accession.