• 한국작물학회지
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• 제43권4호
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• pp.273-278
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• 1998

Carbohydrate metabolism and partitioning are dependent on relationships between sources and sinks which can be affected by rates of photosynthesis and respiration. Fructan, the major form of stored carbohydrate in tall fescue (festuca arundineacea Schreb.), changes in concentration during growth and in response to the environment. Objectives of this study were i) to examine the content and the composition of carbohydrates in five tissues (mature leaf blade, immature leaf blade, leaf elongation zone, terminal meristem, and root tips) of two tall fescue genotypes, one with high yield per tiller (HYT) and one with low yield per tiller (LYT), and ii) to compare the reserved and utilized carbohydrates among above five different tissues, particularly between the leaf elongation zone and root tips. The established vegetative tillers of the HYT and LYT genotypes were grown in a controlled-environment growth chamber. Water-soluble carbohydrate (WSC) in the leaf elongation zone was about 22% of dry weight in the HYT and about 19% in the LYT genotype. The root tip also had high WSC, about 12% of dry weight in the HYT and 6% in the LYT genotype. Hexoses and sucrose were the major components of total WSC in all tissues except the leaf elongation zone. The growing tissues (sinks), i.e., the leaf elongation zone and root tip, had a high proportion of low degree of polymerization fructan, i.e., 3 to 8 hexose units.

• Journal of Ecology and Environment
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• 제33권1호
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• pp.59-65
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• 2010

Because seagrass production significantly contributes to the biodiversity and production of coastal and estuarine ecosystems, accurate estimation of seagrass productivity is a critical step toward understanding the ecological roles of seagrass in these ecosystems. To develop an accurate and effective method of measuring seagrass productivity, we estimated leaf productivity of eelgrass (Zostera marina) on the southern coast of Korea using three methods, the conventional leaf marking method, the elongation-mass method (Short '87 method), and the plastochrone method. In each season, shoots were pierced through the bundle sheath using a hypodermic needle and were collected after 2-4 weeks had elapsed to estimate their productivity. The leaf elongation and the leaf plastochrone intervals varied significantly among seasons. On an annual basis, the conventional leaf marking method showed the lowest leaf productivity estimates compared to the elongation-mass method and the plastochrone method, suggesting that the conventional leaf marking method underestimated leaf productivity as it ignored leaf maturation processes and new leaf growth within the sheath. Since the elongation-mass method considered leaf maturation processes, this method produced higher leaf productivity estimates than the conventional leaf marking method. On an annual basis, the plastochrone method produced the highest leaf productivity estimates. Below-ground productivity, which can be easily estimated using the plastochrone method, ranged between 3.29 and 5.73 (mg dry weight $shoot^{-1}\;day^{-1}$) and accounted for about 17.8% to 30.3% of total productivity. Because of the high contributions of below-ground productivity to total seagrass production, we suggest that the plastochrone method is an effective and simple technique for assessing both above- and below-ground productivities.

• 한국초지조사료학회지
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• 제8권3호
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• pp.104-109
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• 1988

A field experiment was conducted in order to investigate the seasonal changes of leaf growth and related characteristics in three cultivars of orchardgrass; Potomac, Kay and Sumas. The results were summarized as follows: 1. Leaf elongation was increased in a nearly linear phase during first and third cutting stages. It was increased slowly in early 10 days to 15 days after cutting and increased rapidly thereafter during the rest cutting stages. In cultivars, Potomac was showed hlgher leaf elongation than other cultivars during all cutting stages. There was no difference of leaf width within cutting stages, but the leaf width of fall regrowth was narrow. Sumas had relatively short and wide leaves. 2. Leaf dry weight and leaf area in first cutting stage were larger than others. Leaf area was increased rapidly from 15 days after cutting and leaf $we$ was increased rapidly from 20 days over all cutting stages. The increase in leaf area and dry weight were slow down after 30 days. 3. Number of epidermal cells was increased rapidly after cutting and the rate of increase was slow down after 30 days. In a cross section of leaf tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissues. Leaf tissue had a large vacancy at early growth period after harvest and was filled gradually with mesophyll. This result was related to the increase of leaf dry matter.

• 한국작물학회지
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• 제49권2호
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• pp.121-125
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• 2004

In plants, nitrogen is the major component for growth and development. Leaf growth is based on the division, elongation and maturation of cells, which are used for making of epidermis, mesophyll, bundle sheath, xylem, phloem and so on. Dynamics of these tissues with respect to nitrogen are required for better understanding. This experiment was conducted to evaluate effect of nitrogen on the elongation of epidermal and guard cell of two rice (Oryza sativa L.) varieties, Seoanbyeo and Dasanbyeo on May 2000 at Chungbuk national university in Cheongju. After transplaning the 20-day-old seedlings into a/5000 pots, the main characteristics related with cell elongation were investigated and evaluated. A maximum. leaf length reached at 7 or 8 days after emerging from the collar, and also the leaf elongation rates were greatly affected by the increase of N application rate. The initial and final cell length were about $17\mu\textrm{m}$ and $130\mu\textrm{m}$, respectively. Cell divisions occurred within 1.0mm from leaf base. With die higher nitrogen application rate of 22 kg-N $10\textrm{a}^{-1}$, cell division per hour was greater 1.5 to 1.9 and 1.2 to 1.3 fold as compared to the N application rate of 0 and 11 kg-N $10\textrm{a}^{-1}$, respectively. Cell enlargement of epidermal and guard cell under higher N application rate (22kg-N $10\textrm{a}^{-1}$) was finished within about 20 (Seoanbyeo) and 15 hours (Dasanbyeo), while it took much time, about 30 hours.

• 한국토양비료학회지
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• 제37권1호
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• pp.25-30
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• 2004

본 연구는 벼 유묘기 자외선 처리에 의한 엽 신장과 출현양상의 변화를 알아보고자 수행하였다. 벼 유묘의 엽신장은 엽령에 따라 다르게 나타났다. 자외선 조사는 무처리와 비교할 때 58-66%의 엽 신장을 감소시켰다. 자외선 처리 또는 무처리 조건하에서의 엽 생장은 주로 주간에 이루어지는 졌다. 자외선에 의한 3엽의 생장은 무처리에 비해 1.7배정도 억제되었으나, 5엽 생장은 큰 차이가 없었다. 또한 스트레스에 의한 식물체내 지질과산화는 catalase와 peroxidase 활성저하로 인하여 증가하였다. 이상의 결과로 지속적인 자외선 노출은 엽 생장을 억제였으며 유묘기에 영향이 더 컸다.

• 한국작물학회지
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• 제27권3호
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• pp.238-242
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• 1982

단간 조숙품종인 그루밀을 재료로 하여 '80년 4월 15일부터 5월 30일까지 5일 간격으로 10회에 걸쳐 유수, 절간, 엽초 등의 길이를 조사한 자료를 가지고 이들 각각의 신장과 상호 관련성을 분석한 결과를 요약하면 다음과 같다. 1. 동기간(4월 15일- 5월 30일) 중에 유수는 0.6cm에서 8.3cm로 신장하였으며, 출수전 20일(4월 25일)부터 급신장하기 시작하여 술수전 5일(5월 10일)에 그 신장을 거의 완료하였는데 이 기간 중 일당 4.4mm의 신장을 보였고 가장 신장량이 컸던 시기는 술수전 15일부터 10일 사이로 이 때는 일당 6.5mm씩 신장하였다. 2. 절간장중 제 3절간의 신장도 유수의 신장시기와 거의 일치하였으며 출수전 20일부터 급신장하여 출수전 5일에 그 신장을 완료하였다. 3. 엽초장 중 제 1 엽초의 신장시기와 그 양상이 유수의 신장과 또한 일치하였다. 4 유수는 제3절간장과 $r=.974^{***}$, 제1 엽초장과는 $r=.954^{***}$의 상관을 보였고, 제3절간장은 제1엽초장과 $r=.995^{***}$로 이들은 서로 고도의 유의적인(0.1%) 정의 상관을 보였다.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.137-142
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wildtype ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2003년도 식물바이오벤처 페스티발
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• pp.49-55
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wild-type ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

• 한국초지조사료학회지
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• 제8권2호
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• pp.104-109
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• 1988

A field experiment was conducted in order to investigate the seasonal changes of leaf grwoth and related characteristics in three cultivars of orchardgrass; Potomac, Kay and Sumas. The results were summarized as follows: 1. Leaf elongation was increased in a nearly linear phase during first and third cutting stages. It was increased slowly in early 10 days to 15 days after cutting and increased rapidly there-after during the rest cutting stages. In cultivars, Potomac was showed higher leaf elongation than other cultivars during all cutting stages. There was no difference of leaf width within cutting stages, but the leaf width of fall regrwoth was narrow. Sumas had relatively short and wide leaves. 2. Leaf dry weight and leaf area in first cutting stage were larger than others. Leaf area was increased rapidly form 15 days after cutting and leaf weight was increased rapidly from 20 days over all cutting stages. The increase in leaf area and dry weight were slow down after 30 days. 3. Number of epidermal cells was increased rapidly after cutting and the rate of increase was slow down after 30 days. In a cross section of leaf tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissues. Leaf tissue had a large vacancy at early growth period after harvest and was filled gradually with mesophyll. This result was related to the increase of leaf dry matter.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2005년도 제12회 학술대회 논문초록
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• pp.43-43
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• 2005