• 한국연초학회지
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• 제18권2호
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• pp.138-144
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• 1996

This experiment was conducted to obtain the basic information on the morphological and physiological changes in tobacco leaf during the growth period by measuring the changes of chlorophyll, sugar, lipid and mineral contents in tobacco plant. Leaf length and width have been fully developed at 25 days after leaf emergence. Dry weight was rapidly increased between 10 and 15 days after leaf emergence and reached the highest at 30 days. Crude lipid content, palmitic acid, and the major saturated fatty acid were increased with progressing senescence, while unsaturated fatty acid including linolenic acid was decreased as the senescence was advanced. The total nitrogen content showed the highest value at IS days after leaf emergence. On the other hand, the total sugar content showed the highest value at 45 days after leaf emergence and glucose, fructose and sucrose were decreased with leaf development and increased at the end of senescence. The content of chlorophyll showed the highest value at 15 days after leaf emergence and began to decrease at 30 days after leaf emergence. The contents of p, Cu, Zn, and Fe in tobacco leaves were decreased by the end of senescence after leaf emergence but those of Ca, Mg, and Mn in leaves were increased. Key words : Nicotiana tabacum chlorophyll, fatty acid, senescence.

• 한국작물학회지
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• 제41권5호
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• pp.563-568
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• 1996

담배 생육단계별 RNA, protease 활성도와 단백질 패턴의 변화를 파악하여 노화가 진행되는 과정에서 생리 ㆍ생화학적인 변화의 기초자료를 얻고자 본 실험을 수행하였으며 결과는 다음과 같다. 가용성 단백질 함량은 출엽 후 15일까지 증가하여 출엽 후 35일까지 일정하게 유지하였다. 총 RNA 함량은 출엽 후 15일에 가장 높았으며 출엽후 30일까지 급격한 감소를 보였다. Protease 활성 변화는 중성 protease (pH 7.8)가 활성이 높았으며 노화말기인 출엽 후 50일부터 갑자기 증가하였다. 전기영동 패턴은 큰 변화가 없었으나 61.0kd의 polypeptide은 출엽 후 35일부터 생성되어 노화말기까지 증가하였다.

• 한국연초학회지
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• 제17권1호
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• pp.20-26
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• 1995

This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.

• 한국작물학회지
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• 제55권3호
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• pp.259-267
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• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• 농업과학연구
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• 제38권2호
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• pp.191-198
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• 2011

Herbicidal effects and crop selectivity of aqueous leaf extracts of sorghum (Sorghum bicolor L.) were evaluated against several weed species for developing sustainable weed management in organic farming. Aqueous sorghum leaf extracts were highly phytotoxic to different weed species. No broadleaf weeds were germinated in the concentration of 5 fold or higher concentrated sorghum leaf extracts and 90% of seed germination was inhibited within that range in grass species. Sorghum leaf extracts strongly inhibited the growth of different weeds by pre-emergence and foliar applications in greenhouse condition. Foliar application of sorghum leaf extracts had a higher inhibitory effect than the pre-emergence application. Broadleaf weed species were more susceptible than grasses to the application of sorghum leaf extract in foliar applications than grasses. Galium spurium, Erigeron candensis, and Rumex japonicus were completely killed at the highest concentrated sorghum leaf extract both in pre-emergence and foliar application. Most broadleaf weed species were inhibited more than 80% at pre-emergence application at 50 fold concentrated sorghum leaf extract. G. spurium, E. candensis, R. japonicus, Eclipta alba, Plantago asiatica and Portulaca oleraeea were most susceptible to sorghum leaf extract in foliar application. Growth of most broad leaf weed species was suppressed by greater than 90% at 50 fold concentrated sorghum leaf extract. Most crop species were tolerant to sorghum leaf extract but shoot growth was slightly reduced by the application of 40~50 fold concentrated extracts, Sorghum leaf extract may used to control weeds in organic fanning without affecting the growth of crop.

• 한국연초학회지
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• 제15권1호
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• pp.63-74
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• 1993

Changes in the amount of ribulose 1, 5-bisphosphate carboxylase/oygenase(=RuBisCO) protein, namely fraction I protein, and the protease activity were determined in the 10th leaf of tobacco(Nicotiana tabacum, var. Ky-57) from 10 days after emergence through senescence at 5 days interval. The amount of RuBisCO per deveined leaf rapidly increased during the early growing season, reached a maximal quantity at the around 20 days after leaf emergence, when the leaf has gone through its most rapid expansion, and began gradually to decrease till 30 days after leaf emergence, thereafter significantly declined to 45 days that the leaf has been dried up partly. The pattern of the ratio of RuBisCO protein to soluble protein in quantity changed similar to that of RuBisCO contents in a leaf, that was 43%, 60%, and 21% at the around 10 days, 20 days, and 45 days, respectively. And RuBisCO contents was linearly correlated with the concentration of chlorophyll(r=0.98) throughout the life span of the leaf. So, it was assumed that the leaf color can be a useful indicator for judging whether RuBisCO contents higher or not in tobacco leaves without homogenization. On the other hand, the protease activities for degradation of casein were assayed at pH 5.5. 7.0. and 8.5 with crude extracts desalted on Sephadex G-25. The highest caseolytic activity was found at pH 5.5 throughout the life sawn of the leaf. Also, the activity at 5.5 became gradually to increase from 30 days after leaf emergence, when RuBisCO protein had became to disappear and remarkably increased in the last stage of senescence, although nitrogen contents of the leaf had reached low levels. The caseolytic activity at pH 5.5 was in negative correlation with RuBisCO contents throughout the life span of the leaf, but not in lineality between them. In other words, the caseolytic activity increased in a rapid exponential manner when RuBisCO contents had reached some low levels. These results showed that the leaf age, namely harvesting time, is a very important factor for the production of the tobacco leaf containing higher RuBisCO protein. It was concluded that the practical harvesting time is between 20 days and 30 days after the leaf emergence from the present results.

• 한국작물학회지
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• 제38권5호
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• pp.449-457
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• 1993

온도가 쌀보리와 맥주보리의 출엽속도와 출엽간격에 미치는 영향을 구명하고자 쌀보리 3품종(능쌀보리, 새쌀보리, 향천과 001)과 맥주보리 3품종(두산 8호, 사천006, 진광보리)을 향온 7수준(4, 8, 12, 16, 20, 24, 28$^{\circ}C$)과 변온 7수준[6/2(명기 / 암기), 10/6, 14/10, 18/14, 22/18, 26/22, 30/$25^{\circ}C$]으로 유지시킨 생장상에서 4엽기까지 키우면서 매일 주간엽수를 조사하여 출엽속도 및 출엽간격를 산출한 결과를 요약하면 다음과 같다. 항온과 변온에 관계없이 공시품종 모두 동일 온도내에 있어서는 출아후 일수가 증가됨에 따라 주간 출엽수도 직선적으로 증가되었다. 평균기온 28$^{\circ}C$를 제외하고는 출아속도와 출아간격이 항온과 변온간에 현저한 차이를 보이지 않았다. 출아속도와 출아간격은 품종간에 유의한 차이가 있었고 동일 품종내 온도간에도 현저한 차이가 있었다. 평균기온이 증가됨에 따라 일당 출아속도는 출아 최적온도까지 곡선적으로 증가된 다음 감소되었는데, 6품종의 출아 최적온도는 20.1～21.5$^{\circ}C$로 품종간 현저한 차이는 없었으나 출아 최적온도에서의 출엽속도는 쌀보리가 0.202～0.226엽/일, 맥주보리가 0.231～0.241엽/일으로 맥주보리가 큰 경향이었다. 평균이온이 증가됨에 따라 유효적산온도당 출엽속도는 지수함수적으로 감소되었고, 출엽간격(일엽당 적사온도)은 지수함수적인 증가를 보였는데, 6품종의 평균 출엽간격은 4$^{\circ}C$에서 46.2GDD/엽, 28$^{\circ}C$에서 129.3GDD/엽이었다.

• 한국작물학회지
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• 제39권5호
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• pp.502-511
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• 1994

벼 건답직파에서 벼 품종들의 출아·입모 특성과 유아의 신장 특성과의 관계를 검토하고자 국내의 재래종, 육성종 및 샤레벼, 미국 직파재배품종, 이태리 품종 등 98개 품종을 토중 4.5cm에 파종하여 적습과 과습조건하에서 출아율, 입모율, 평균출아일수, 중배축장, 하위절간장, 초엽장, 불완전엽장 등을 조사하여 얻은 결과는 다음과 같다. 1. 적습조건에서 입모율은 9∼92.5%, 평균출아일수는 12∼25일 범위였고, 과습조건에서의 출아율은 0∼90%, 평균출아일수 27∼34일로 양조건 모두 품종간 변이가 매우 컸으며, 대부분의 품종은 과습조건에서 출아율이 낮아지고 출아속도가 늦어졌다. 2. 출아·입모율과 유의한 정의 상관을 보인 형질은 적습조건에서는 중배축장, 초엽장, 불완전엽장이었고, 과습조건에서는 중배축장, 제1, 2절간장, 초엽장, 불완정엽장이었다. 3. 평균발아일수는 중배축장, 초엽장, 불완전엽장과 유의한 부의 상관을 나타내었다. 4. 표준편회귀분석결과 출아·입모의 품종간 차이에 가장 유의적으로 기여하는 형질은 적습조건에서는 중배축장과 초엽장, 과습조건에서는 중배축장과 제2절간장이었다. 5. 평균출아일수의 품종간 차에 유의적으로 기여하는 형질은 적습조건에서는 중배축장, 불완전엽장으로 회귀계수는 부의 방향이었으며, 제1,2절간장은 정의 방향이었다. 과습조건에서는 중배축장만이 유의적 기여를 하였는데 회귀계수는 부의 방향이었다. 6. 본 실험의 결과로 볼 때 건답직파조건에서 출아율이 높고 출아속도가 빠른 품종을 육성하기 위해서는 중배축, 초엽 및 불완전엽의 신장이 잘되는 특성의 선발이 바람직한 것으로 사료된다.

• Journal of Ginseng Research
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• 제19권3호
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• pp.275-280
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• 1995

The formation of thylakoid membrane proteins and changes in the chloroplast ultrastructure of ginseng leaf were investigated as a function of time following the leaf emergence. The leaf chloroplast obtained just after the leaf emergence showed short rod-like thylakoids which were connected and arranged in 3~4 layers along the longitudinal axis of the chloroplast. The 10 DAE (days after emergence) chloroplast started to form grana structure. The typical grana structure was observed 17 DAE, and the grana was fully developed 28 DAE. The membrane proteins obtained from just after emerging leaf were separated into many minor bands indicating no CP-complex formation yet. LHC II was detected after 10 days. CP 47 and CP 43 were detected after 17 days. After 28 days, the PS I and PS II proteins were distinctly separated into CP 1, LHC II, CP 47, CP 43, CP 29, CP 27+24. Thus, the appearance of the light harvesting protein, LHC II, which was concentrated in grana stacks, was consis tent in time with the formation of grana stacks 17 DAE. Key words Chloroplast ultrastructure, grana, CP-complex, LHC II.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.207-211
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• 2008

We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan, Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence, Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed, However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives, As a result, small ramets were semi-evergreen, whereas large ramets were deciduous, The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.