• 한국연초학회지
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• 제18권1호
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• pp.66-75
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• 1996

This study was carried out to investigate the effects of high temperature and humidity on the ageing of processed leaf tobacco. Four(1993) or six(1994) grades (Both flued-cured and burley) of processed leaf packed in carton box were stored under the natural and artificial conditions. When the Processed leaf was stored in the controlled mom at 40℃ with 75% R.H.(1993) for 40 days, the leaf pH was decreased. The decreasing rate of leaf pH was similar to that of leaf stored under the natural warehouse condition for 15 months. The degree of lightness and yellowness of leaf also decreased, while the decaying or darkening of the leaf was observed. When the processed leaf was stored in the controlled room at 35℃ with 65% R.H.(1994) for 90 days, the pH of flue-cured was decreased 0.22, which was similar to that of the leaf stored under the natural warehouse condition for 15 months, and the lightness, and redness of the leaf were higher than those of the control. As compared with the leaf stored under the natural condition for 2 years, the smoking quality of leaf stored under this condition was similar or somewhat better. The pH of burley tobacco changed little compared to that of flue-cured during storage in this study.

• 오토저널
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• 제3권1호
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• pp.38-45
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• 1981

In this paper, the natural frequencies of curved taper leaf springs using on vehicle suspension systems are studied. By applying the Castigliano's definition, Rayleigh's principle and Dunkerley's equation, new formulas defining the natural frequency of such shaped spring are derived. Numerical calculations are in very good agreement with experimental results on actual models. We found that the natural frequencies of curved taper spring are increased by 21-28% compared with the spring having same weight, span and curve but uniform section.

• 한국작물학회지
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• 제40권6호
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• pp.723-730
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• 1995

콩의 건물축적과 단백질전류에 대한 Source-Sink변경의 효과를 구명하기 위하여 1992년에 고려대학교 자연자원대학 실험농장에서 황금콩을 공시품종으로 착협시기(R3)에 상위 40%, 하위 60%의 엽과 협을 제거하여 건물중 및 단백질함량의 변화를 조사한 결과는 다음과 같다. 1. 상엽-하협제거처리에서 하위 엽과 경 건물중이 증가하였고, 상위 종실과 협 건물중은 감소하였다. 2. 엽의 단백질함량은 상위 엽보다 하위 엽에서 높았다. 3. 종실의 단백질함량은 상엽-하협제거와 하엽-상협제거처리에서 낮았다. 4. 상엽-하협제거처리에서 엽의 단백질함량은 가장 높았고 종실 단백질함량은 가장 낮았다. 5. 본 실험의 결과에서 콩의 단백질원은 하부에서 상부로 이동하나 생식생장기간중의 장거리 전류를 위한 엽 단백질의 재이동은 약한 것으로 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.17-17
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• 2022

Leaves are an important organism for photosynthesis and transpiration. The shape of leaf is crucial factor affecting plant architecture. V-shape leaf rolling is enhancing canopy photosynthesis by increasing the CO₂ penetration and the light capture by reducing the shadow between the leaves. Therefore, moderate leaf rolling is thought to more high grain yield per area than flat leaf. We investigated 278 KRICE_CORE accession's Adaxial Leaf Rolling Index (LRI) in first heading using the following equation. For each accession, genomic DNA was used for sequencing. We sequenced the genomics with ~8 X coverage to detect SNPS. Raw reads were aligned against the rice reference (IRGSP 1.0) for SNP identification and genotype calling. To generate genotype data for GWAS, SNPs were filtered with minor allele frequency 0.05. Finally, 841,134 high-quality SNPs were used for our GWAS. The significant threshold was -log10(P)>7.23. From the results, 2 significance SNP were detected. Considering the LD block of 250kbp, 60 candidate gene were selected including Hypothetical gene and Conserved gene. In this poster, we analyzed candidate gene affecting adaxial Leaf Rolling through single-trait GWAS.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.243-243
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• 2022

Leaves are an important organism for photosynthesis and transpiration. The shape of leaf is crucial factor affecting plant architecture. V-shape leaf rolling is enhancing canopy photosynthesis by increasing the CO₂ penetration and the light capture by reducing the shadow between the leaves. Therefore, moderate leaf rolling is thought to more high grain yield per area than flat leaf. We investigated 278 KRICE CORE accession's Adaxial Leaf Rolling Index (LRI) in first heading using the following equation. For each accession, genomic DNA was used for sequencing. We sequenced the genomics with ~8 X coverage to detect SNPS. Raw reads were aligned against the rice reference (IRGSP 1.0) for SNP identification and genotype calling. To generate genotype data for GWAS, SNPs were filtered with minor allele frequency 0.05. Finally, 841,134 high-quality SNPs were used for our GWAS. The significant threshold was -log10(P) >7.23. From the results, 2 significance SNP were detected. Considering the LD block of 250kbp, 60 candidate gene were selected including Hypothetical gene and Conserved gene. In this poster, we analyzed candidate gene affecting adaxial Leaf Rolling through single-trait GWAS.

• 한국식품저장유통학회지
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• 제21권4호
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• pp.529-535
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• 2014

본 연구는 전통적으로 방부 또는 살균효과가 있어 떡 등에 첨가되거나 저장 및 포장에 이용되었던 자생식물 15종 21건에 대하여 데하이드로초산(sodium dehydroacetate), 소르빈산(sorbic acid), 안식향산(benzoic acid), 파라옥시안 식향산메틸(methyl p-hydroxybenzoate), 파라옥시안식향산에틸(ethyl p-hydroxybenzoate), 파라옥시안식향산프로필(propyl p-hydroxybenzoate), 파라옥시안식향산이소프로필(isopropyl p-hydroxybenzoate), 파라옥시안식향산이소부틸(isobutyl p-hydroxybenzoate), 파라옥시안식향산부틸(butyl p-hydroxybenzoate), 프로피온산(propionic acid)의 함유량을 분석하였다. 솔잎, 망개잎, 대나무잎 등 15종에 대한 천연유래 보존료 함유량을 조사한 결과 솔잎, 대나무잎, 칡잎, 모시잎, 쑥, 잣나무잎 등 6종에서 안식향산, 소르빈산, 프로피온산을 확인할 수 있었다. 안식향산은 대나무잎, 모시잎, 솔잎, 쑥, 칡잎, 잣나무잎에서 8.201~21.839 mg/kg, 소르빈산은 대나무잎과 칡잎에서 5.630~24.995 mg/kg, 프로피온산은 모시잎에서 61.324~62.726 mg/kg이 검출되었다. 조사 식물 중 망개잎, 토란잎, 조릿대, 연잎, 원추리, 구절초, 떡갈나무잎, 산초잎, 감잎 등 9종에서는 천연보존성분이 검출되지 않았다.

• Fisheries and Aquatic Sciences
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• 제25권8호
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• pp.409-416
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• 2022

This study aims to know the effect of water-extracted horseradish Moringa oleifera leaf and KW21 fertilizer combination application on the density of Nannochloropsis sp. It was conducted in the Natural Food Laboratory of State Polytechnique, Tual. The experiment used complete randomized design with 5 treatments and 3 replications: A (25% horseradish leaf extract + 75% KW21), B (50% horseradish leaf extract + 50% KW21), C (75% horseradish leaf extract + 25% KW21), D (positive control of 100% KW21), and E (negative control of 100% horseradish leaf extract). Results showed that Treatment C yielded the best result, both the highest density of Nannochloropsis sp. and suitable harvest time.

• 한국산림과학회지
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• 제84권2호
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• pp.186-197
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• 1995

경기도 양평 지역에 생육하고 있는 리기다소나무, 낙엽송, 졸참나무 임분의 지상 부위 생체량과 엽면적을 추정하기 위해 흉고직경, 흉고단면적, 변재단면적, 변재부피 등의 변수를 이용하는 회귀식을 조제하였다. 지상 부위 생체량과 엽면적은 흉고직경, 흉고단면적, 변재단면적, 변재부피 등과 각각 통계적으로 유의한 상관 관계를 보였으며, 비슷한 직경급에서 3수종 모두 유사한 수간목부 생체량을 보였다. 그러나 수피, 잎, 가지와 지상 부위 총생체량과, 단위건중량당 엽면적 그리고 엽면적 변재단면적의 비에 있어 수종 간 차이가 뚜렷하였다. 생체량과 엽면적 추정을 위한 회귀식은 대상 수중의 잎의 습성과 수병에 영향을 받는 것으로 보이며, 이들 영향을 보다 확실하게 구명하치 위해서 상세한 연구가 필요한 것으로 사료된다.

• Journal of Life Science
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• 제11권1호
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• pp.14-21
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• 2001

To investigate the changes of carbohydrate metabolism in the senescing leaves of Zea mays during dark-induced senescence, the changes in the contents of reducing sugar, sucrose and starch as well as the activities of sucrose synthase, three isozymes of invertase, and ${\alpha}$-amylase were measured. In the senescing leaves, the content of reducing sugars temporarily increased at 4 d and rapidly decreased thereafter, whereas sucrose contents gradually decreased thereafter, whereas sucrose contents gradually decreased until 3 d of senscence and significantly decreased thereafter. The activities of intracellular invertases such as soluble acid and alkaline formed gradually enhanced until 4 d of leaf senescence and significantly declined thereafter. The extracellular invertase activity showed no significant changes during leaf senescence. The deactivation of sucrose synthase was observed within 3 d of leaf senscence. On the other hand, the starch contents gradually declined during 2 d of leaf senescence, and showed a temporary increase at 3 d, which is similar to the pattern of sucrose synthase activity., These results imply that sucrose in the senescing leaves. The major enzymes which correlated to the breakdown of sucrose during dark-induced senescence were soluble acid and alkaline invertases, not sucrose and ABA accelerated leaf senescence by inducing the accumulation of reducing sugar. These result, therefore, that leaf senescence may be mediated by the temporary quantitative changes of reducing sugar induced by the activation of intracellualr inveertases.

• Journal of Ginseng Research
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• 제35권4호
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• pp.449-456
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• 2011

Plant leaf cuticle is related to the prevention of moisture loss, transpiration, and diffusion of light reflection. The purpose of this study was to examine the morphological characteristics of ginseng leaves in ginseng plants resistant and susceptible to hightemperature injury (HTI) to be related with the leaf-burning. For the HTI resistant lines Yunpoong, high-temperature injury resistance (HTIR) 1, HTIR 2, and HTIR 3, and the HTI-susceptible line Chunpoong, the cuticle densities were 53.0%, 46.2%, 44.9%, 48.0%, and 17.0%; the adaxial leaf cuticle layers were 141.3, 119.7, 119.7, 159.4, and 85.0 nm in thickness; the abaxial leaf cuticle layers were 153.6, 165.8, 157.9, 199.6, and 119.4 nm in thickness; and the stomtal lengths were 21.7, 32.4, 29.4, 30.9, and $21.8{\mu}m$, respectively. All of these aspects suggest that HTI resistant lines have higher cuticle density, thickicker adaxial and abaxial leaf cuticle layers, and longer of stomta length than the HTI-susceptible line, protecting leaves from moisture loss and excessive transpiration under high temperatures to be resistant against the leaf-burning.