• 한국육종학회지
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• 제43권1호
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• pp.1-13
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• 2011

Low temperature stress is one of the major negative factors affecting vegetative and reproductive growth of rice. To better understand responses of rice plants to low temperature we analyzed transcriptome expression patterns in glumous flower of cold-tolerant japonica rice variety, Stejaree45, and cold-susceptible variety, HR19621-AC6 at booting stage under cold water irrigation. A total of 2,411 probes were differentially expressed by low temperature in glumous flowers of the two varieties. Some important genes involved in hormone biosynthesis showed variety-specific regulation. Expression of GA20ox3 and GA2ox, among the genes involved in GA biosynthesis, was regulated differentially in the two varieties. Among the genes involved in IAA biosynthesis, YUCCA1 and TAA1:1 showed variety-specific regulation. Among the genes involved in cytokinin biosynthsis and signaling, expression of LOG, HK1 and HK3 was significantly down-regulated only in the cold-susceptible variety. Among the genes involved in ABA biosynthesis, NSY and AAO3 were down-regulated only in the cold-tolerant variety. In general, genes involved in GA, IAA and cytokinin biosynthesis responded to cold temperature in such a way that capacity of those bioactive hormones is maintained at relatively higher levels under cold temperature in the cold-tolerant variety, which can help minimize cold stress imposed to developing reproductive organs in the cold-tolerant variety.

• 한국작물학회지
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• 제32권4호
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• pp.403-408
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• 1987

사질답을 Zeolite 가용에 의한 증수효과의 실증을 해석적으로 평가하고저 1986년 공시품종 '봉광'를 사용해서 표준재배법으로 관리하여 조사분석한 결과를 다음과 같이 요약한다. 1 Zeolite 가용에 의하여 토양중의 K는 116%, Ca는 l8%, SiO$_2$는 22%, 그리고 CEC는 14%가 각각 증가하였다. 2. 10a당 백미수량은 542kg로서 표준재배구보다 11% 증수되었다. 이것은 주당수수가 많고, 임실율이 높고 수당입수도 많은 것에 기인되었다. 또한 1,000입중 및 1$\ell$중이 무겁고, 쇄미율은 낮고 밥맛은 좋았다. 3. 특이한 상관반응으로서는 정조수량-수중비율이 높은 정상관이며, 정상관이 인정되는 것은 주당수수-수중비율 및 등숙율-정조수량이다. 높은 부상관은 정조 1.000입중-제 4ㆍ5절 간장 비율이였다. 4. 수량에 대한 수량구성요소의 직접효과는 등숙율이 가장 컸으며, 다음으로 큰 것은 수당입수였다. 5. 출수기 35일후의 식물 각기관의 건물중은 표준재배구보다 모두 무거웠으며, 특히 생엽은 26%, 경+엽초는 19%, 그리고 수는 5%나 각각 무거웠다. 6. 수의 1차지경 끝부위의 착립비율은 전착립수의 47%이며, 그의 상반부의 착립비율은 37%이다. 그리고 수축의 최선단에도 많이 착립하는 정전화의 우세효과가 뚜렷하였다.효과가 뚜렷하였다.

• 한국작물학회지
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• 제59권1호
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• pp.59-65
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• 2014

Ethephon을 처리하여 트리티케일의 간장을 단축시켜 도복을 방지하는 방법을 찾기 위하여 시험한 결과 Ethephon 처리시 출수기는 수잉기에 처리했을 때는 무처리에 비해 250 ppm과 500 ppm 농도에서는 2일, 1,000 ppm 이상에서는 4일이 늦어졌으나, 개화기와 성숙기는 차이가 없었다. 간장은 Ethephon 농도가 높을수록 작아졌고, 간장 단축률은 수잉기의 1,500 ppm 처리가 37%의 단축률로 처리 효과가 가장 컸으며, 하위절보다 상위절의 단축률이 컸다. 수장, 영화수, 리터중 등에서 무처리와 큰 차이가 없었고, 천립중은 무처리에 비해 약간 무거웠다. 발아율은 차이가 없었으며, 수량은 처리 농도에 관계 없이 모두 증수하는 경향을 보였으며, 수잉기 1,000 ppm 처리에서 최고 5%까지 증수하였다. 발아에 영향을 미치지 않으면서 수확시기를 앞당길 수 있는 방법을 찾고자 실시한 건조제 처리 후 수확시기 단축효과와 종자의 품질을 보면, 건조제 처리후 수확적기 수분함량에 도달하는 일수는 출수 후 30일 처리가 15일, 출수 후 35일 처리가 10일이 걸렸고, 출수 후 40일과 45일 처리가 5일이 걸다. 건조제 처리 후 수확시기는 출수 후 30일과 35일 처리가 관행재배에 비해 8일, 출수 후 40일 처리가 5일이 빨랐다. 건조제 처리시 천립중은 출수 후 처리 일수가 늦어질수록 무거웠고, 발아율 또한 출수 후 처리 일수가 늦어질수록 높아지는 경향을 보였으나, 출수 후 35일 이후에는 통계적인 유의성은 없었다. 수량은 출수 후 30일 처리구가 관행재배의 37% 수준, 출수 후 35일 처리가 70%수준이었고 출수 후 40일 처리가 92% 수준으로 생리적 성숙기 이전에 건조제를 처리하면 품질에 큰 영향을 준다.

• 한국농공학회지
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• 제24권4호
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• pp.69-79
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• 1982

The objective of this study is to contribute to drainage planning in the most realistic and economical way by establishing the relationship between rice yield reduction and overhead flooding by muddy water of each growth stage of paddy, which is the most important factor in determining optimum drainage facilities. This study was based on the data mainly from the experimental reports of the Office of Rural Development of Korea, Reduction Rate Estimation for Summer Crops, published by Ministry of Agriculture and Forestry of Japan and other related research documenta- tion. The results of this study are summarized as follows 1. Damages by overhead flooding are highest in heading stage and have the tendency of decrease in the order of booting stage, panicle formation stage, tillering stage, and stage just after transplanting. Damages by overhead flooding of each growing stage are as follows: a) It is considered that overhead flooding just after transplanting gives a little influence on plant growth and yield because the paddy has sufficient growth period from floo ding to harvest time. b) Jt is analyzed that according to the equation y=11 12x 0.908 which is derived from this study, damages by overhead flooding during tillering stage for 1, 2, 3 successive days are 11.1 %, 20.9%, and 30.2% respectively. c) Damages by overhead flooding after panicle formation stage are very serious because recovering period is very short after damage and ineffective tillering is much. Acc- ording to the equation y=9. 58x+10. Ol derived from this study, damages by overhead flooding fal 1,2,3,5 successive days are 19.6%, 29.2%, 38.8%, 57.9% respectively. d) Booting stage is the very important period in which young panicle has grown up almost completely and the number of glumous flower is fixed since reduction division takes place in the microspore mother cell and enbryo mother cell. According to the equation y=39. 66x 0.558 derived from this study, damages by overhead floodingfor 0.5, 1, 3, 5 successive days are 26.9%, 39.7%, 72. 2% and 97.4%, respectively. Therefore, damages by overhead flooding is very serious during the hooting stage. e) When ear of paddy emerges, flowering begins on that day or the next day; when paddy flowers, fertilization will be completed 2-3 hours after flowering. Therefore overhead flooding during heading stage impedes flowering and increases sterilizing percentage. From this reason damages of heading stage are larger than that of booting stage. According to the equation y-41 94x 0.589 derived from this study, damages by overhead flooding for 0.5, 1, 3, 5, successive days are 27.9%, 63.1 %, 80.1%, and 100% 2. Considering that temperature of booting stage is higher than that of beading stage and plant height of booting stage is ten centimeters shorter than that of heading stage, booting stage should be taken as a critical period for drainage planning because possi- bility of damage occurrence in booting stage is larger than that of heading stage. There-fore, it is considered that booting stage should be taken as critical period of paddy growth for drainage planning. 3. Overhead flooding depth is different depending on the stage of growth. In case, booting stage is adopted as design stage of growth for drainage planning, it is conside red that the allowable flooding depth for new varieties and general varieties are 70cm and 80cm respectively. 4. Reduction Rate Estimation by Wind and Flood for Rice Planting of the present design criteria for drainage planning shows damage by overhead flooding for 1 to 2, 3 to 4, 5 to 7 consecutive days; damages by overhead flooding varies considerably over several hours and experimental condition of soil, variety of paddy, and climate differs with real situation. From these reasons, damage by flooding could not be estimated properly in the past. This study has derived the equation which shows damages by flooding of each growth stage on an hourly basis. Therefore, it has become possible to compute the exact damages in case duration of overhead flooding is known.