• 한국작물학회지
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• 제61권3호
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• pp.163-170
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• 2016

Heading time is important element for yield and quality in crops. Among day length and temperature which influence on heading, temperature effect has not been investigated well. To investigate temperature effect on heading, heading date and plant growth characters were checked under the low and high temperature conditions in short day length. Analyzing heading date of six Korean varieties under the high and low temperature condition, heading date of varieties were delayed under low temperature. In the low temperature condition, dry weight and area of leaf were reduced. Varieties showing more delay of heading under low temperature also showed more reduction in leaf area. After selecting three varieties showing significant difference in leaf growth and heading date under different temperature conditions, nutrient contents of plant were analyzed. Nitrogen content was reduced in leaf and shoot under the low temperature condition. OsNRT2.3, nitrate transporter, was significantly down regulated in varieties showing more heading delay. Available phosphate content was decreased in leaf, but increased in shoot due to reduction of phosphate mobility. OsPT1, phosphate transporter regulating phosphate uptake, was more down regulated in varieties showing more heading delay. OsPT6, phosphate transporter regulating phosphate transport in plant, was also significantly down regulated in those varieties. With these data, we expected that active nitrogen and available phosphate uptake and transport in plant would increase leaf growth then might reduce heading delay under the low temperature condition.

• 한국초지조사료학회지
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• 제15권2호
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• pp.124-131
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• 1995

In order to find out optimum seed production date according to different defoliation and flooding period of Italian ryegrass, this studies with Tetrone were canied out on the experimental field of Honam Crop Experiment Station from 1986 to 1988. Treatments included cutting date of Nov. 20 and Apr. 10 and flooding period of 5-25 days. In soil after experiment, organic matter, phosphate and silicate content increased, but potassium content decreased 0.16% than that before experiment. Heading and maturing date of Nov. 20 cutting were same with those of non cutting, those of Apr. 10 cutting lates 6 days to heading date and 2 days to maturing date. Plant height and culm length of Nov. 20 cutting were sirniller to those of non cutting, those of Apr. 10 cutting were shorter and panicle length have no difference between non cutting and cutting. Lodging of cutting treatment was reduced than that of non cutting. Lodgin was increased as flooding period was long, also loding of all treatment occured at 30 days after heading. Two cutting times of Nov. 20 and Apr. 10 have the most fresh yield, while non cutting have the most dry matter yield. Optimun seed productin date was considered to suitable when 35 days after heading (Jun. 14), at this time, seed production was 1,640 to 2,640 kg/ha. Also if flooding j u r y have, seed production was good between 10 days and 15 days after flooding.

• 한국작물학회지
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• 제64권3호
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• pp.213-224
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• 2019

There is an increasing frequency in the occurrence of abnormal weather phenomena such as sharp increases and decreases in temperature. Under these weather conditions, the heading time of rice changes unexpectedly, which poses problems in agriculture. Therefore, we investigated the effect of temperature on the heading response at different growth stages in rice. During the period from transplanting to heading, the plants were subjected to different temperature treatments, each for a 9-day period, to observe the heading response. For the heading date analysis, "heading date" was defined as the number of days from transplanting to the appearance of the first spikelet. We found that the influence of temperature increased in the order of rooting stage, followed by meiosis, early tillering, spikelet differentiation, and panicle initiation stage in all ecological types and cultivars. In particular, unlike the results reported previously, the effect of temperature on heading during the photo-sensitive period was very small. Meanwhile, the influence of temperature on vegetative growth response at different growth stages was not consistent with heading response. These results can be used as basic data for predicting the variation in heading date owing to temperature variation at each growth stage. In addition, we propose that the concept of day length should be included in determining the influence of temperature on the photo-sensitive period.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.80-80
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• 2022

Estimation of heading date of paddy rice is laborious and time consuming. Therefore, automatic estimation of heading date of paddy rice is highly essential. In this experiment, deep learning classification models were used to classify two difference categories of rice (vegetative and reproductive stage) based on the panicle initiation of paddy field. Specifically, the dataset includes 444 slanted view images belonging to two categories and was then expanded to include 1,497 images via IMGAUG data augmentation technique. We adopt two transfer learning strategies: (First, used transferring model weights already trained on ImageNet to six classification network models: VGGNet, ResNet, DenseNet, InceptionV3, Xception and MobileNet, Second, fine-tuned some layers of the network according to our dataset). After training the CNN model, we used several evaluation metrics commonly used for classification tasks, including Accuracy, Precision, Recall, and F1-score. In addition, GradCAM was used to generate visual explanations for each image patch. Experimental results showed that the InceptionV3 is the best performing model in terms of the accuracy, average recall, precision, and F1-score. The fine-tuned InceptionV3 model achieved an overall classification accuracy of 0.95 with a high F1-score of 0.95. Our CNN model also represented the change of rice heading date under different date of transplanting. This study demonstrated that image based deep learning model can reliably be used as an automatic monitoring system to detect the heading date of rice crops using CCTV camera.

• 한국작물학회지
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• 제66권4호
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• pp.289-296
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• 2021

쌀가루 가공용벼 품종인 한가루, 설갱, 신길 및 바로미2의 수발아 발생 위험을 감소하기 위한 지역별 적합 이앙기 및 이에 따른 등숙기 생육온도, 수발아 발생 위험성을 변화를 분석한 결과는 다음과 같다. 1. 쌀가루 품종의 출수기변화요인을 분석한 결과, 이앙부터 출수까지 일 평균온도 및 이앙시기변화는 포장생육일수와 부의 상관관계를 보이며 이앙시기변화에 따른 포장생육일수 변화는 유의한 상관관계를 보였다. 2. 이를 바탕으로 수발아 발생위험성 감소를 위해 등숙기 온도를 최저로 낮추기 위해 각 지역별로 안전출수한계기에 출수할 수 있는 이앙시기를 분석한 결과 대략 5월 초순(강원지역)~6월 중순(남부 내륙지역) 혹은 6월 하순(남부 해안지역)이 이앙적기로 판단되었다. 3. 각 품종별로 이앙적기에 이앙 시 수발아 발생 위험이 있는 등숙적산온도 700℃ 및 900℃의 평균온도를 분석한 결과 700℃의 경우 대체로 약 20℃, 900℃의 경우 18℃의 온도를 나타내었다. 4. 쌀가루 가공용 품종의 수발아 발생가능성을 분석한 결과, 바로미2을 제외하고는 등숙적산온도 700℃ 및 900℃에 등숙기 온도가 20℃ 미만 시 수발아 발생율은 높지 않은 것으로 판단되었다. 5. 바로미2의 경우 다른 품종에 비해 등숙기간중 수발아 발생위험성이 높아 낮은온도에서 수발아 발생위험성을 재검정하여 이앙시기를 재설정할 필요성이 있다.

• Journal of Crop Science and Biotechnology
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• 제10권4호
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• pp.243-248
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• 2007

Rice is a facultative short-day plant that flowers in response to reduced day lengths. This study was conducted to identify quantitative trait loci(QTL) for the early heading date(EHD) using H143 line showing extreme EHD compared to other regular cultivars in rice. The japonica H143 was crossed with a japonica cultivar 'Dongjinbyeo' as well as a tongil cultivar 'Milyang23' to measure the inheritance mode of EHD and identify major QTL conferring EHD, respectively. Pooling test revealed that segregation distortion occurred on chromosome 7 and subsequent linkage map was constructed using 10 SSR markers. QTL analysis using Q-gene 3.06 revealed that the EHD trait in H143 was largely controlled by two major QTL, EH7-1 and EH7-2, accounting for more than 40% of genetic variation that were closely related to the previously reported QTL, Hd4 and Hd2, respectively. This result suggests that these two QTL markers may be a useful source for the control of heading date in rice breeding programs.

• 한국작물학회지
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• 제2권
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• pp.11-26
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• 1964

파종기의 이동이 수도의 출수기 및 기타 수량구성용소 등 제형질에 미치는 영향 및 품종간 변이를 알고저 50품종을 공시하여 3월 15일부터 7월 28일까지 15일간격을 두고 10회에 걸쳐 파종하고 20일묘와 40일묘를 이식하여 그 특성을 조사하여 제I보로 '파종기 및 묘대기간의 차이가 출수기에 미치는 영향 및 품종간의 변이'를 보고한바 있다. 본보는 제1보에 계속된 것으로 40일묘이앙구에 대한 벼의 간장, 수장, 수수, 수종 및 고간종 등 수량구성요소에 대하여 1년간의 실험성적을 조사분석하였다. 제I보에서 보고한 바와 같이 파종기가 지연됨에 따라 출수까지의 일수가 단축되었으며 대부분의 품종은 제VIII파종기까지는 거의 직선적 단축경향을 보였으며 일부의 품종은 제IX파종기까지 그러한 경향을 보였고 제X파종기에서는 거의 전부가 출수하지 못하였다. 따라서 파종기이동에 따르는 출수까지의 일수의 변화가 수량구성요소에 미치는 영향 및 품종간의변이에 관하여 본실험의 결과를 요약하면 다음과 같다. 1. 간장 : 간장은 파종기의 이동에 따라 출수까지의 일수가 단축되면 간장도 짧아지는 경향을 보였으며 각파종기에 있어서 품종적으로 보면 출수까지의 일수가 긴 것은 간장이 짧았다. 2. 수장 : 수장은 파종기의 이동에 따라 출수까지의 일수가 단축되면 수장도 단축되었으며 각파종기에 있어서 품종적으로 보면 출수까지의 일수가 긴 품종은 수장이 짧고 출수까지의 일수가 짧은 품종은 수장이 긴 경향을 보였으나 현저하지는 않았다. 3. 수수 : 1주수수는 품종 및 파종기를 통하여 출수까지의 일수가 길어 질수록 증가하였으며 단 제IX파종기에서 만은 출수까지의 일수가 길면 수수는 감소하였다. 4. 수중 : 1주수중은 품종 및 파종기를 통하여 출수까지의 일수가 길 수록 무거운 경향을 보였는데 제VII 및 제VIII파종기에서는 반대로 출수까지의 일수가 길면 1주수중은 가벼운 경향을 나타냈다. 5. 고종 : 1주고간중은 품종 및 파종기를 통하여 출수까지의 일수가 길어 질수록 무거운 경향을 보였다. 6. 신고비 : 신고비는 제1파종기로부터 점차 높아져서 제V파종기에 최고에 달하였고 각파종기에 있어 품종적으로 보면 제I∼제III파종기와 제VII∼제VIII파종기에 있어서는 출수까지의 일수가 길면 신고비는 낮고 그밖에 파종기 즉 보통재배인 제IV 및 제V, 제VI파종기에서는 출수까지의 일수가 길면 신고비가 높았다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.225-225
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• 2022

Rice is a major food crop consumed by approximately half of the world's population. Heading date is one of the major agronomic traits and has a wide impact on the productivity and quality of rice. Recently, shortening the growth period of rice through modulating heading date has been emphasized as one of the most effective strategies for reducing methane emissions from paddy fields. OsPRR37, a major heading date gene in rice, represses flowering under both short-day and long-day conditions. Plants carrying the loss-of-function alleles of OsPRR37 have been reported to flower approximately seven days and 20 days earlier than those carrying the functional alleles in short day and long day conditions, respectively. In this study, we investigated the nucleotide sequence variation existing in the exonic regions of OsPRR37 and catalogued the allelic distribution in 208 Korean rice cultivars. We used four sets of primers for amplifying and sequencing the eight exons of OsPRR37. As a result, two types of loss-of-function alleles and four types of functional alleles were found in 208 Korean rice cultivars. Interestingly, only three cultivars (Jinbuolbyeo, Jinseolchal, and Mimyeon) carried loss-of-function alleles while 205 carried functional alleles, indicating that OsPRR37 loss-of-function alleles have been used very rarely in Korean rice breeding programs. To generate useful information for the development of early-maturing rice cultivars, our future work will focus on analyzing the effect of different OsPRR37 alleles on heading date and other major agronomic traits.

• 한국초지조사료학회지
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• 제14권1호
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• pp.42-49
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• 1994

To examine the productivity, growth characteristics, and nutritive value of forage rye at the southern region of Korea, fourteen varieties of rye were sown at Nov. 13, 1992 at the plot of experiment farm of Crop Experiment Station, Mokpo Branch, and over winter survival rate, heading date, yield, yield components and nutritional values were measured. All the varieties used in this experiment showed 100% over winter survival rate at the sowing date of Nov. 13. Heading dates of all the varieties ranges from Apr. 25 to May 10, which seems to be early enough to get high yield. The varieties, Paldal-hod, and Danko introduced from Japan appear to be the most recommended ones in the southem region of Korea. They showed early heading date of Apr. 25, large plant height, greater number of leaves, high yield, low content of crude fiber and crude fat, high crude protein, NFE, and crude a5h.

• Plant Resources
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• 제5권2호
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• pp.155-160
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• 2002

The heading date is known to be controlled by two kinds of genetic constituent, photosensitivity and basic vegetable phase. For the latter, the effect of temperature in early growth period is critical to determine the shortness of vegetative growth periods in plant's life. A phytotron experiment on 55 rice cultivars, consisting of two ecotypes of rices, indica and japonica, was conducted at high and low temperature treatments at early growth stage to investigate the possible role of plant growth stimulus by high temperature to associate with shortening of heading date. The high temperature during the early growth stage stimulated the rice growth as measured by plant height with much difference of the growth response between indica and japonica. The conclusive finding that these growth stimulus in early growth stage was highly correlated with the acceleration of heading is, more or less, correlated with the heading of the late growth stage although we could not conclude the genes for early plant growth stimulus by high temperature is the same genes as the genes for accelerating of heading in the late growth stage of plants.