• 원예과학기술지
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• 제19권4호
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• pp.555-559
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• 2001

본 연구는 유도일장과 강광도 조건에서 화아발달 시기에 간이 엽록소 측정기(SPAD-502 chlorophyll meter)를 이용한 국화잎의 위치별 엽록소 함량변화를 조사하기 위하여 실시하였다. SPAD 값은 수확기에 줄기의 최상부에서부터 매 3엽씩 하부로 내려가면서 서로 다른 일장과 광도조건에서 측정하였다. 10시간의 단일에서 SPAD 값이 가장 높았고, 뒤를 이어 13시간과 16기간 일장 순이었다. 특히 단일조건에서는 화아의 아래로부터 첫 번째인 가장 어린잎에서 가장 높았으며, 줄기의 하부로 내려갈수록 감소하였다. 장일조건에서는 줄기의 상부에서 15-27번째의 잎이 가장 높은 SPAD 값을 나타내었고, 줄기 최상단의 어린잎에서는 최소값을 기록하였다. 이러한 결과는 단일 조건에서는 상부의 잎들이 발달하는 꽃들을 지지하기 위한 중요한 소스(source)가 되는 반면, 영양생장기의 국화는 상부에서 분화 또는 발달하는 어린잎이 여전히 중요한 싱크(sink)의 하나로서 역할하고 있는 것으로 판단된다. SPAD 값은 강광도 조건에서 증가하였고, 광도가 낮아짐에 따라 감소하였다.

• 한국초지조사료학회지
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• 제38권2호
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• pp.140-144
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• 2018

To investigate the impact of nitrogen (N) mineral on reproductive potential of Brassica napus L, plants were treated with different levels of N treatment ($N_0$; $N_{100}$; $N_{500}$). The half of N content for each treatment were applied at the beginning of the early vegetative stage and the rest was applied at the late vegetative stage. Nitrogen content in plant tissues such as root, stem and branch, leaf, pod and seed was analyzed and harvest index (HI) was calculated as percentage of seed yield to total plant weight. Biomass and nitrogen content were significantly affected by different levels of N supply. Biomass was significantly decreased by 59.2% in nitrogen deficiency ($N_0$) but significantly increased by 50.3% in N excess ($N_{500}$), compared to control ($N_{100}$). Nitrogen content in all organs was remarkably increased with nitrogen levels. N distribution to stem and branches, and dead leaves was higher in N-deficient ($N_0$) and N excessive plants ($N_{500}$) than in control ($N_{100}$). However, nitrogen allocated to seed was higher in control ($N_{100}$) than in other treatments ($N_0$ or $N_{500}$), accompanied by higher HI. These results indicate that the optimum level of N supply ($N_{100}$) improve HI and N distribution to seed and excessive N input is unnecessary.

• 한국초지조사료학회지
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• 제8권1호
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• pp.20-25
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• 1988

This experiment was conducted to find out the effects of the different cutting height on the chemical composition, energy production and relation of yields of Italian ryegrass, tall fescue and perennial ryegrass swards. It was carried out on the experimental field of Livestock Experiment Station, in Suweon, from Sept. 1986 to May 1987. The results obtained are summarized as follows: 1. Chemical composition and Van Soest fiber contents were slightly different among grasses. But were not same trend with cutting heights. At the late vegetative stage, crude protein and crude fiber content were much more in tall fescue, Ash in perennial ryegrass, E.E. and NFE in Italian ryegrass respectively. NDF, ADF, Hemicellulose, Lignin, Cellulose and Silica contents were much more in tall fescue than the others. 2. DM, DCP, TDN, StE, ME and NEL productions were appeared to high in line with Italian ryegrass, perennial ryegrass and tall fescue. In addition 6 cm cutting height was the most production in Italian ryegrass, 15 cm cutting height was the most production in perennial ryegrass and tall fescue. 3. The much more content of crude protein, the less nonstructural carbohydrate content. The less content of NDF, the much more nonstructural carbohydrate content. Green and dry matter yield before wintering were not influence the green and dry matter yield of the late vegetative stage, but green yield before wintering influenced total green yield.

• 한국초지조사료학회지
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• 제20권4호
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• pp.285-294
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• 2000

To investigate the effect of Mycorrhiza (Glomus intradics) and Rhizobium inoculation on the N, P utilization and growth response of Alfalfa (Medicago saliva L.) and Perennial ryegrass (Lolium perenne L.) in mixed sward, four treatments (non-inoculation, Control; Mycorrhiza inoculation: M; Rhizobium inoculation, R and Mycorrhiza and Rhizobium inoculation, M+R) were applied. The associated analyses were canied out on the early vegetative growth stage (DAS 56, 56 days after seeding) and on the early flowering stage (DAS 126). The decreased rate of total N and P content in soil, with advancing plant growth, was relatively higher in the M and M + R treatment than control. The content of availabie phosphorus in soil at DAS 126 increased by about 34 and 38 % in M and M+R treatment compared to control (189.2 mg PzOskg DM), while non-significant changes was observed in R treatment. Total N uptake and P uptake in the control at DAS 126 were 44.71 and 3.52 mglplant in mixed sward, respectively. About 71, 98 and 197 % of increases in total N uptake and 70, 72 and 11 1 % of increases in total P uptake were estimated in M, R and M+R treatment. Comparing to control, total dry matter yield significantly increased by 27, 33 and 53 %, and crude protein yield also by 78, 83 and 204 %, respectively, in M, R and M+R treatment. The present data indicated that mycorrhiza orland rhizobium inoculation improved N, P utilization of both alfalfa and perennial ryegrass plants, and consequently increased total yield (especially by dual inoculation, M+R). (Key words : Alfalfa, Perennial ryegrass, Mycorrhiza, Rhizobium, N and P Utilization, Growth, Yield)

• 한국초지조사료학회지
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• 제20권4호
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• pp.275-284
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• 2000

To investigate the effect of Mycorrhiza (Glomus intradics) and Rhizobium inoculation on the N, P utilization and the growth of Alfalfa (Medicago sativa L.), four treatments (non-inoculation, control ; Mycorrhiza inoculation, M ; Rhizobiurn inoculation, R and Mycorrhiza and Rhizobium inoculation, M+R) were applied. The associated analyses were carried out on the early vegetative growth stage (DAS 56, 56 days after seeding) and on the early flowering stage (DAS 126). The decreased rate of total N and P content in soil, with advancing plant growth, was relatively higher in the mycorrhiza andor rhizobium treatments than control. The content of available phosphorus in soil at DAS 126 increased by about 40 % in M and M+R treatment compared to control (141.0 mg PzOg'kg DM), while non-significant changes was observed in R treatment. Total N uptake and P uptake in the control at DAS 126 were 33.91 mglplant and 2.42 mdplant, respectively, about 21, 50 and 51 % of increases in total N uptake and 30, 11 and 47 % of increases in total P uptake were estimated in M, R and M+R treatment. Comparing to control, dry matter yield significantly increased by 8, 27 and 28 %, and crude protein yield also by 21, 42 and 39 %, respectively, in M, R and M+R treatment. The present data indicated that mycorrhiza orland rhizobium inoculation improved N, P utilization, and consequently increased the yield of alfalfa. (Key words : Alfalfa, Mycorrhiza, Rhizobium, N and P Utilization, Growth, Yield)

• 한국작물학회지
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• 제47권4호
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• pp.311-318
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• 2002

Planting date of soybeans [Glycine max (L.) Merr.] is one of production components in cultural systems. The objective of the current study was to identify the components of soybean production and cultural practices encompassing planting dates and cultivars that respond to dry matter accumulation, harvest index and yield components. Three determinate soybean cultivars were planted on May 13 (early), June 3 (mid), and June 24 (late). Planting density was 60$\times$15cm with 2 seeds (222,000 plants per ha). Soybean plants were sampled every 10 days interval from the growth stages of V5 to R8 and separated into leaves including petioles, stems, pods, and seeds. Dry matter accumulations, harvest indices, and yield components were measured. Early planting had taken 55 days from VE to R2 and late planting taken 39 days indicating reduced vegetative growth. Early planting showed higher leaf, stem, pod and seed dry weights than late planting. However, late planting appeared to be higher harvest index and harvesting rate. Vegetative mass including leaf and stem increased to a maximum around R4/R5 and total dry weight increased to a maximum around R5/R6 and then declined slightly at R8. The highest seed yield was obtained with mid planting and no difference was found between early and late plantings. Cultivar differences were found among planting dates on growth characteristics and yield components. The results of this experiment indicated that soybean yield in relation to planting dates examined was mainly associated with harvest index and harvesting rate, and planting date of cultivars would be considered soybean plants to reach the growth stage of R4/R5 after mid August for adequate seed yield.

• Molecules and Cells
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• 제40권10호
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• pp.773-786
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• 2017

The loss of green coloration via chlorophyll (Chl) degradation typically occurs during leaf senescence. To date, many Chl catabolic enzymes have been identified and shown to interact with light harvesting complex II to form a Chl degradation complex in senescing chloroplasts; this complex might metabolically channel phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show that an oshcar knockout mutant exhibits persistent green leaves during both dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar mutants exhibit severe cell death at the vegetative stage; this cell death largely occurs in a light intensity-dependent manner. In addition, 7-HMC a treatment led to the generation of singlet oxygen ($^1O_2$) in Arabidopsis and rice protoplasts in the light. Under herbicide-induced oxidative stress conditions, leaf necrosis was more severe in hcar plants than in wild type, and HCAR-overexpressing plants were more tolerant to reactive oxygen species than wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to Chl a in senescent leaves, HCAR may play a critical role in protecting plants from high light-induced damage by preventing the accumulation of 7-HMC a and Pheo a in developing and mature leaves at the vegetative stage.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.133-133
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• 2022

Temperature is a crucial environmental factor for rice cultivation due to the climate change and can influence the rice growth and development. Therefore, the effect of temperature on plant growth characters was examined during the vegetative stage. Plants were grown under three different temperatures: 23℃/13℃ for 18℃, 26℃/16℃ for 21℃ and 29℃/19℃ for 24℃ in the phytotron. The temperature was treated after transplanting and ended in early panicle initiation stage. Heading date of the two varieties were strongly affected by the temperature and were delayed in the 18℃. The plant height in the 18℃ was 21 % shorter than the 21℃ and 24℃ and the tiller and leaf number were increased in the 18℃. All the growth rates of the characters were the slowest in 18℃. The stem dry weight was significantly increased in 18℃. Nitrogen content was increased in the leaves of 18℃ whereas available phosphate and potassium content was found to be increased in the stems of 21℃ and 24℃. OsNRT 2.1 was overexpressed in the leaves and stems of 18℃ and OsNRT2.3a could be expressed in 18℃ and 21℃ temperatures whereas more expressed in 21℃. OsPT1 and OsPT6 could be expressed in the leaf of 18℃ and 24℃ but could be expressed in the stem of 18℃. OsHAK1 and OsHAK5 could be overexpressed in the leaves and stems of 18℃. For hormone, OsCKX2 gene was found to be up regulated in the leaves of 18℃ and OsIAA1 gene could be expressed more in the stem of 24℃.

• 한국농림기상학회지
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• 제8권3호
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• pp.125-131
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• 2006

이상기후에 의한 재해환경 대응 및 대책자료로 활용하고자 2003년 남부 산간고냉지를 중심으로 발생한 저온 피해에 대한 원인과 특성을 조사한 결과는 다음과 같다. 남부산간고냉지(운봉)의 생식생장기 평균기온은 $19.7^{\circ}C$로 평년대비 $3.1^{\circ}C$낮았고, 일조시간은 79시간으로 평년대비 49% 수준으로 경과되었으며, 냉해가 발생한 시기는 유수형성기인 6월 하순부터 감수분열기인 7월 중순까지로 이 시기의 기온이 $17^{\circ}C$이하의 저온으로 경과하여 장해영 냉해가 발생하였다. 지역별 저온 피해면적은 남원 2,723ha 순창 510ha, 진안 300ha, 장수 210ha이었으며, 이들 지역의 평균 불임율은 44%이었다. 이앙시기에 따른 불임율은 5월 20일경에 적기 이앙재배를 한 경우 $16%{\sim}58%$로, 4월 하순에 조기이앙재배시의 $29%{\sim}83%$에 비해 낮았으며, 오대벼, 운봉벼 진부벼 등의 품종이 저온피해 정도가 적었다. 따라서 냉해가 우려되는 지역에서는 기상조사 및 분석에 의한 벼 재배 작기를 고려하고, 가급적 지나친 조기 이앙을 지양하며, 내냉성이 강한 품종을 재배하여야 할 것으로 생각된다.

• 한국농림기상학회지
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• 제21권4호
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• pp.269-276
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• 2019

본 연구는 지구온난화로 인한 콩 생육기간 중 한발기간에 따른 생육 특성과 수량 구성요소 변화에 대한 연구 결과로서 대조구에 비하여 VS와 FS는 수량에 직접적인 영향을 주었다. 한발은 잎의 노화를 가속하여 LAI, 잎 질소 농도 및 잎 건물중이 감소하였다. 이러한 결과 품종과 한발 기간이 LAI, 잎 질소 농도 및 잎 건물중이 고도로 유의하였다. 최종 수확에서 전체 협수는 대조구에 비하여 VS와 FS가 각각 33.6%와 40.5%가 감소였고, 100립 중은 대조구에 비하여 VS와 FS가 각각 16.1%와 10.1%가 감소하였다. 이러한 결과 종실 수량은 대조구에 비하여 VS와 FS가 각각 39.8%와 45.1%가 감소하였다. 한발 기간에 따라 대원콩과 해원콩이 수량 감소 폭이 큰 반면에 소연콩은 크지 않았다. 본 연구 결과 한발 기간은 VS에 비하여 FS가 좀 더 민감하게 반응을 하였으며, 품종과 한발기간은 고도의 유의성을 보였다. 본 연구에서 주목할 것은 개화기 10일전부터 착협기까지 수분 공급이 제대로 이루어 진다면 주경에서의 협수와 100립 중이 확보가 되어 수량 감소를 방지할 것으로 기대된다.