• 한국작물학회:학술대회논문집
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• 한국작물학회 1993년도 추계 학술대회지
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• pp.52-53
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• 1993

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 춘계학술발표회 요지
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• pp.154-155
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• 2005

• 한국산림과학회지
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• 제86권2호
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• pp.167-176
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• 1997

희귀수종인 모감주나무(Koelreuteria paniculata Laxm.) 6개 자생 집단에 대해서 잎의 형태적 특성 및 식생개황을 조사하였으며, 동위효소 분석에 의한 유전변이를 조사하였다. Nested design에 의한 분산분석 결과 8가지 잎의 형태적 특성 모두에서 집단간 및 집단내 개체간에 고도의 통계적 유의성이 인정되었으며, 대부분 형질의 경우 총 분산 가운데 집단간 차지하는 비율이 집단내 개체가 차지하는 비율보다 큰 것으로 나타났다. 식생분석 결과 각 집단별로 출현한 수종 수는 많지 않았으며, 대부분 집단이 인위적 교란을 받고 있는 것으로 나타났다. 다른 수종, 특히 지리적으로 광범위하게 분포하는 수종들과 비교할 때 유전변이는 매우 적고(A/L= 1.1, P=9.5%, $H_o=0.021$, $H_e=0.035$) 집단간 분화($F_{ST}=0.114$)는 다소 큰 것으로 나타났는데, 유전적 부동 및 근친교배의 영향을 받고 있는 것으로 추정되었다. 마지막으로 모감주나무 집단의 유전적 다양성을 보전하기 위한 방법에 대해서 논의하였다.

• 한국작물학회지
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• 제29권3호
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• pp.209-217
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• 1984

남부 다모작지대의 도작 증수재배법을 확립하고자 이앙시기를 5월 20일부터 7월 5일까지 15일 간격, 4시기로 하여 수량 형질 및 수량변이를 검토한 결과를 요약하면 다음과 같다. 1. 엽수의 변이는 서광벼에서는 5월 20일 이앙구의 16.2매에 대하여 만식한 7월 5일 이앙구는 15.1매로 1.1매가 적었고 동진벼는 5월 20일 이앙구 14.8매에 대하여 7월 5일 이앙구는 13.1매로 1.7매가 적었다. 2. 지엽단축률은 작기가 늦어짐에 따라 커지는 경향이었다. 3. 작기 이동에 따른 출수일수의 변이는 서광벼는 5월 20일 이앙에서 약 75 일, 6월 5일은 68일, 6월 20일은 67일 정도이었으나, 7월 5일은 71일이 소요되었다. 4. 재배시기에 따른 최대수량은 서광벼는 5월 20일, 동진벼는 6월 20일 이앙이었고 수량생산기의 적산온도와의 관계는 서광벼는 1017$\pm$24$^{\circ}C$에서, 동진벼는 952$\pm$15$^{\circ}C$에서 600kg/10a 이상의 고위수량을 보였다. 5. 단위면적당 수수는 작기가 늦어짐에 따라 직선적으로 감소되는 부의 유의 상관관계(서광벼 r=-0.6768＊＊, 동진벼 r=-0.5182＊＊)가 인정되었다. 6. 작기 이동에 따른 1수 영화수는 서광벼는 작기가 늦어짐에 따라 많아졌고 동진벼는 작기가 빠르거나 늦은 경우 감소경향을 보였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.239-239
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• 2017

The enhancement of leaf photosynthetic capacity can have the potential to improve the seed yield of soybean. Key targets for the increase of leaf photosynthetic capacity remains unclear in soybean. Peking, Chinese local variety, has been the useful material for soybean breeding since it shows various resistances against biotic and abiotic stress. Sakoda et al., 2017 reported that Peking had the higher capacity of leaf photosynthesis than Enrei, Japanese elite cultivar. They identified the genetic factors related to high photosynthetic capacity of Peking. The objective of this study is to elucidate the physiological basis underlying high photosynthetic capacity of Peking. Peking and Enrei were cultivated at the experimental field of the Graduate School of Agriculture, Kyoto University, Kyoto, Japan. The sowing date was July 4, 2016. Gas exchange parameters were evaluated at the uppermost fully expanded leaves on 43, 49, and 59 days after planting (DAP) with a portable gas exchange system, LI-6400. The leaf hydraulic conductance, $K_{leaf}$, was determined based on the water potential and transpiration rate of the uppermost fully expanded leaves on 60 DAP. The morphological traits related to leaf photosynthesis were analyzed at the same leaves with the gas exchange measurements. The light-saturated $CO_2$ assimilation rate ($A_{sat}$) of Peking was significantly higher than that of Enrei at 43 and 59 DAP while the stomatal conductance ($g_s$) of Peking was significantly higher at all the measurements (p < 0.05). It suggested that high $A_{sat}$ was mainly attributed to high $g_s$ in Peking. $g_s$ is reported to be affected by the morphological traits and water status inside the leaf, represented by $K_{leaf}$, in crop plants. The tendency of the variation of the stomatal density between two cultivars was not consistent throughout the measurements. On the other hand, $K_{leaf}$ of Peking was 59.0% higher than that of Enrei on 60 DAP. These results imply that high $g_s$ might be attributed to high $K_{leaf}$ in Peking. Further research is needed to reveal the mechanism to archive high $g_s$ on the basis of water physiology in Peking. The knowledge combining the genetic and physiological basis underlying high photosynthetic capacity of Peking can be useful to improve the biomass productivity of soybean.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.98-98
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• 2017

Leaf senescence is the process of aging in plants. Chlorophyll degradation during leaf senescence has the important role translocating nutrients from leaves to storage organs. The functional stay-green with slow leaf yellowing and photosynthesis activity maintenance has been considered one of strategy for increasing crop productivity. Here, we have identified two QTLs on chromosome 9 and 10 for leaf senescence with chlorophyll content of RIL population derived from a cross between Hanareum 2, early leaf senescence Indica-type variety, and Unkwang, delayed leaf senescence Japonica variety. Among these QTLs, we chose qPLS1 QTL on chromosome 9 for further study. qPLS1 was found to explain 14.4% of the total phenotypic variation with 11.2 of LOD score. Through fine-mapping approach, qPLS1 QTL locus was narrowed down to about 25kb in the marker interval between In/del-4-7-9 and In/del-5-9-4. There are 3 genes existed within 25kb of qPLS1 locus: LOC_Os09g36200, LOC_Os09g36210, and LOC_Os09g36220. Among these genes, transcript level of LOC_Os09g36200 was increased during the leaf senescence stage and the expression level of LOC_Os09g36200 in Indica was higher than in Japonica. Finally, we chose LOC_Os09g36200 as candidate gene and renamed it as OsPLS1-In and OsPLS1-Jp from Indica- and Japonica-type rice, respectively. OsPLS1-In and OsPLS1-Jp overexpressing transgenic plants showed both early leaf senescence phenotype. These results indicate that OsPLS1 functions in chlorophyll degradation and the difference of expression level of OsPLS1 cause the difference of leaf senescence between Indica and Japonica in rice.

• 한국작물학회지
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• 제43권4호
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• pp.250-253
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• 1998

Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines ($R_2$ generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine $R_2$ lines (7%) segregated for pubescence and 130 $R_2$ lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine $R_2$ lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.

• 한국약용작물학회지
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• 제10권5호
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• pp.375-378
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• 2002

5월부터 10월까지 병풀의 지상부에 triterpene glycosides인 madecassoside와 asiaticoside의 시기별 함량변화를 조사하였다. 잎에서는 9월에 약 108.1 mg/g으로 가장 높은 수준의 함량을 보였다. 엽병에서는 19.02 mg/g으로 잎에서 보이는 수준보다는 낮은 수준을 나타냈다. 병풀의 triterpene glycosides는 잎에 주로 축적되며, 가장 적절한 병풀의 수확시기는 9월로 잠적 확인되었다.

• 한국토양비료학회지
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• 제46권4호
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• pp.245-252
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• 2013

Leaf area index (LAI) is important in explaining the ability of crops to intercept solar energy for biomass production, amount of plant transpiration, and in understanding the impact of crop management practices on crop growth. This paper describes a procedure for estimating LAI as a function of image-derived vegetation indices from temporal series of RapidEye imagery obtained from 2010 to 2012 using empirical models in a rice plain in Seosan, Chungcheongnam-do. Rice plants were sampled every two weeks to investigate LAI, fresh and dry biomass from late May to early October. RapidEye images were taken from June to September every year and corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). Linear, exponential, and expolinear models were developed to relate temporal satellite NDVIs to measured LAI. The expolinear model provided more accurate results to predict LAI than linear or exponential models based on root mean square error. The LAI distribution was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when RapidEye imagery was applied to expolinear model. The spatial trend of LAI corresponded with the variation in the vegetation growth condition.

• 한국주조공학회지
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• 제12권5호
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• pp.403-411
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• 1992

The growth characteristics of bainite at early stage in the fast quenched spheroidal graphite cast irons containing 0.06%Mn and 0.45%Mn during austempering process, was investigated with optical and scanning electron microscope. The following results regarding the effects of Mn and isothermal heat treatment on the morphological variation of bainitic ferrite were obtained. The morphology of bainite varies from acicular below 350$^{\circ}C$ to feather shape above 350$^{\circ}C$. The period of isothermal treatment also affects the shape of bainite at the fixed temperature. At 350$^{\circ}C$, bainite is bamboo leaf-like up to 200 secs of isothermal holding time and with further increasing time up to 300 secs, changes to a mixed structure consisting of both feather and bamboo leaf and, finally becomes all feather shape at 900 secs. The morphology of bainitic ferrite formed at early stage of 300$^{\circ}C$ isothermal treatment is similar to that of bainitic ferrite formed at 250$^{\circ}C$ or 350$^{\circ}C$ with unbranched, linear ferrite. However, bainitic ferrite divides into branches with increasing isothermal treatment, which occurs more fast at 400$^{\circ}C$ than at 350$^{\circ}C$. The difference in adding amount of Mn influences the morphology of bainitic ferrite in upper bainite. The bainitic ferrite with 0.45%Mn is observed to be more stable than that with 0.06%Mn, remaining unbranched for a longer period at the same temperature.