• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.21-21
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• 2017

Severe lodging has recurrently occurred at strong typhoon's hitting in recent climate change. The identification of quantitative trait loci (QTLs) and their responsible genes associated with a strong culm and their pyramiding are important for developing high-yielding varieties with a superior lodging resistance. To identify QTLs for lodging resistance, the tropical japonica line, Chugoku 117 and the improved indica variety, Habataki were selected as the donor parent, as these had thick and strong culms compared with the temperate japonica varieties in Japan such as Koshihikari. By using chromosome segment substitution lines (CSSLs) in which chromosome segments from the japonica variety were replaced to them from Habataki, we identified the QTLs for strong culm on chrs. 1 and 6, which were designated as STRONG CULM1 (SCM1) and STRONG CULM2 (SCM2), respectively. By using recombinant inbred lines (BILs) derived from a cross between Chugoku 117 and Koshihikari and introgression lines, we also identified the other QTLs for strong culm on chrs. 3 and 2, which were designated as STRONG CULM3 (SCM3) and STRONG CULM4 (SCM4), respectively. Candidate region of SCM1 includes Gn1 related to grain number. SCM2 was identical to APO1, a gene related to the control of panicle branch number, and SCM3 was identical to FC1, a strigolactone signaling associated gene, by performing fine mapping and positional cloning of these genes. To evaluate the effects of SCM1~SCM4 on lodging resistance, the Koshihiakri near isogenic line (NIL) with the introgressed SCM1 or SCM2 locus of Habataki (NIL-SCM1, NIL-SCM2) and the another Koshihikari NIL with the introgeressed SCM3 or SCM4 locus of Chugoku 117 (NIL-SCM3, NIL-SCM4) were developed. Then, we developed the pyramiding lines with double or triple combinations derived from step-by-step crosses among NIL-SCM1 NIL-SCM4. Triple pyramiding lines (NIL-SCM1+2+3, ~ NIL-SCM1+3+4) showed the largest culm diameter and the highest culm strength among the combinations and increased spikelet number due to the pleiotropic effects of these genes. Pyramiding of strong culm genes resulted in much increased culm thickness, culm strength and spikelet number due to their additive effect. SCM1 mainly contributed to enhance their pyramiding effect. These results in this study suggest the importance of identifying the combinations of superior alleles of strong culm genes among natural variation and pyramiding these genes for improving high-yielding varieties with a superior lodging resistance.

• 현장농수산연구지
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• 제17권1호
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• pp.101-111
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• 2015

The purpose of this study is to identify any differences in academic records of students after they got into the Korea National College of Agriculture and Fisheries through the entrance exam. The target group was the students of 1,035 who enrolled from the year of 2012 to 2014 by the exams respectively, and this study compared those first year's records. As a result, this study found that their academic achievements have no significant differences statistically. With regard to the result, we could recognize that the average achievements of students are arithmetically high, who were accepted by admission officer's interview(talented students of agriculture and fisheries) and regular admission procedure to which the scholastic test result is applied. Accordingly, it is more desirable that we should rather focus on measures to improve the admission procedure that could contribute to academic achievements of students who are mostly accepted through the nonscheduled admission. It is pointless to focus on discussion that the achievement of students selected by a particular procedure is low. That kind of criticism proved groundless. Secondly, the study of the correlation between their admission records and after admission records of the freshmen in 2012 shows that a significant difference does not exist whereas those of in 2013 and 2014 has a slightly different statistically, though a coefficient of correlation was a mere 0.17. It account for this result that KNCAF has increased the applied-rate of highschool transcript from 33.3% to 50.0.% in admission procedure from the year of 2013. However, lowering the applied-rate of farming and fishing background is not everything as we consider the graduates' easy settling into rural area. It is a well-known fact that after graduation, the majority of students who have applied for a grace period of the delay in performing the obligation of farming and fishing, and of students who have paid the school expenses back came from ones with no sufficient foothold. This means that we should formulate a supporting policy for the students to settle into rural area smoothly after graduation if we keep the regulation of lowing the applied-rate of farming and fishing.

• 현장농수산연구지
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• 제25권4호
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• pp.90-102
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• 2024

Haploid/double haploid plants developed from isolated microspores can significantly accelerate plant breeding. Haploid plants can naturally double their chromosomes to create a pure homozygous line of diploid plants. We present a method for producing embryos from isolated microspores of hot peppers (Capsicum annuumL.). We analyzed the polyploidization levels of the regenerated plants. The donor plants produced the optimal stage of microspores following short-term growth under low-intensity light, which resulted in high rates of embryogenesis and cotyledonary embryogenesis. To find an efficient culture method, liquid, doubled-layer, and 2-step cultures were tested. Liquid culture yielded the highest number of embryos, whereas the highest efficiency for cotyledonary embryogenesis was afforded by the doubled-layer culture. When normal cotyledonary embryos were transplanted onto a regeneration medium, they developed into complete plants. From these, 208 plants were tested via flow cytometric analysis, and 35.6% and 72.7% of the chromosomes from the Milyang-jare and LV2319 genotypes, respectively, were found to be spontaneous double haploids. These results are the same as those obtained on analyzing horticultural characteristics, including the size of leaves and the size and shape of fruits. The present study provides information on the practical application of isolated microspore culture of hot peppers, factors that affect embryogenesis, and methods for polyploidy testing.

• 현장농수산연구지
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• 제10권1호
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• pp.115-135
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• 2008

• 현장농수산연구지
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• 제11권1호
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• pp.199-218
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• 2009

• 현장농수산연구지
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• 제8권1호
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• pp.97-130
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• 2006

• 현장농수산연구지
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• 제9권1호
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• pp.61-90
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• 2007

• 현장농수산연구지
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• 제24권3호
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• pp.33-43
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• 2022

This study was conducted to monitor the vegetation recovery in the areas damaged by the forest fires on the east coast that occurred in April 2000. The study site was a forest fire-damaged area in Samcheok-si, Gangwon-do, and 21 monitoring areas (12 natural restoration sites, 9 artificial restoration sites) were selected to analyze the vegetation recovery trend since 1998. The vegetation recovery trend was compared by calculating the values according to the year using the difference Normalized Burn Ratio (dNBR) and Normalized Difference Vegetation Index (NDVI) based on satellite images (Landsat TM/ETM+ and Sentinel-2A). As the result of this study, all 21 sites, vegetation was recovered, and both groups showed the greatest recovery in summer. In the case of the dNBR, the artificial restored sites showed higher values than the natural restored sites, and in the case of the NDVI, the natural restored sites were higher than the artificially restored sites in summer and autumn. However, the difference between the two groups of natural and artificial restoration sites was not significant. Therefore, the direction of forest restoration after forest fire damage can be effectively restored if properly implemented for the purpose of restoration of the target site.

• 현장농수산연구지
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• 제25권4호
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• pp.127-137
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• 2024

본 연구는 옥수수의 가공 방식이 한우의 반추위 발효특성과 영양소 소화율에 미치는 영향을 알아보기 위해 수행되었다. 공시재료는 분쇄 옥수수(1mm) 및 옥수수 후레이크(600초-105℃-3mm)를 이용하였으며, 공시동물은 평균체중이 327 ± 41kg인 한우 암소 3두를 실험에 이용하였다. 건물, 전분, NFE 및 NFC의 소화율은 옥수수 분쇄 처리 보다 후레이크 처리에서 더 높았으며, 배양 3시간부터 24시간까지 유의적으로 차이가 있었다(P<0.05). 배양 3시간의 반추위 pH는 분쇄 옥수수에 비해 후레이크 처리에서 낮았으나 48시간 동안의 평균 반추위 pH는 처리간 유의한 차이는 없었다. 평균 아세트산, 프로피온산 및 부티르산 생성량은 분쇄 옥수수에 비해 후레이크 처리에서 유의하게 증가하였다(P<0.05). 본 연구 결과 옥수수의 후레이크 가공은 분쇄 가공에 비해 반추위 내에서 이용효율을 개선시켜 영양소 소화율 향상과 휘발성지방산 생성량 증가에 도움을 줄 수 있을 것으로 판단된다.

• 현장농수산연구지
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• 제26권1호
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• pp.5-15
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• 2024

중국은 버섯 최대 생산국이자 소비국으로, 중국의 버섯 산업 발전은 버섯 생산과 소비 성향이 비슷한 우리나라에 심각한 위협이 되고 있다. 중국의 버섯 산업은 통계자료가 공표되기 시작한 1985년 경에는 5만 톤 생산에 불과하였으나 2020년에는 년간 생산량이 4,000만 톤을 넘는 산업으로 발전하였다. 중국에서 버섯 산업이 급격한 발전은 높은 수익성과 빠른 자금 회전율, 빠른 투자비 회수, 지방정부의 적극적인 지원, 국민 소득 증가에 따른 건강 식품선호 및 소비 증가와 해외 수출 확대, 그리고 자동화 시설재배의 도입 등을 들 수 있다. 최근 중국도 자동화 시설재배에 의한 버섯 생산이 과잉될 가능성이 많기 때문에 대책을 세우지 않으면 국내 시장을 잠식할 가능성이 높다. 따라서 국내의 버섯 농가와 산업을 보호하기 위해서는 중국의 버섯 산업 현황을 정확히 파악하고 분석하여 대비해야 할 것으로 생각된다.