• 한국잡초학회지
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• 제7권3호
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• pp.247-256
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• 1987

The ability of three Echinochloa colona (L.) Link ecotypes to compete with rice (Oryza sativa L.) was evaluated. For all the ecotypes, E. colona was shorter and produced less leaf area and dry matter than rice at 15 days after seeding (DAS), whereas the reverse was observed from 30 to 60 DAS. Neither E. colona nor rice tillered during the first 15 DAS, but E. colona had greater accumulative tiller length than rice from 15 DAS. Rice absorbed more nitrogen than E. colona at 15 DAS. E. colona absorbed greater amounts of nitrogen, phosphorus, and potassium than did rice between 30 and 60 DAS and increase in its density decreased the nutrients uptake of rice. Differences in the competitive ability of the ecotypes were related to the growth characteristics of the ecotypes and the period of competition between the two species. At the early growth stages the Pangasinan ecotype, which increased plant size rapidly and had a shorter life cycle, was more competitive against rice than the Leyte and South Cotabato ecotypes, which had a longer vegetative growth period. However, the reverse was observed at the later growth stages of the ecotypes.

• 한국환경농학회지
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• 제18권1호
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• pp.1-5
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• 1999

유기물 시용 및 벼 기상 생태형별 $CH_4$ 발생양상을 구명하고 이를 근거로 논 토양에서 배출되는 $CH_4$ 배출량을 추정하기 위해 미사질 양토에서 시험한 결과를 요약하면 다음과 같다. 1. 시기별 $CH_4$ 배출은 조생종이 2번의 peak를 나타냈으며 중생종과 만생종은 3번의 peak를 나타냈으며 줄기를 통한 $CH_4$ 배출은 온도가 높을수록 많은 경향이었다. 2. $CH_4$배출량은 조생종에 비하여 중생종과 만생종이 높은 경향이었으며, 볏짚 시용구와 비교해볼 때 볏짚 무시용구에서 46%의 $CH_4$ 배출이 감소되었다. 3. $CH_4$ 배출 계수($gm^{-2}day^{-1}$)는 조생종이 0.394, 중생종이 0.407, 만생종이 0.411이었으며, 볏짚 무시용시 $CH_4$ 배출계수는 조생종이 0.198, 중생종이 0.269, 만생종이 0.273이었다.

• 한국환경복원기술학회지
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• 제6권1호
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• pp.71-77
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• 2003

This research has been conducted to collect regional ecotypes of Poa pratensis throughout the southern part of korean peninsula during 2000~2002. 227 local ecotypes of Poa pratensis were collected mostly from roadsides, riversides and rice paddies. The $35^{\circ}$ latitude was supposed to be the southern limit of native Poa pratensis habitat. 130 ecotypes of Poa pratensis found from the poor environmental condition such as roadsides showed Poa pratensis naturally grew throughout the country. When surveyed the habitat environment, it was concluded that native Poa pratensis were mostly found on open fields or half shaded areas, on sandy soil or sandy loam soil, and in the individual patch type.

• 한국작물학회지
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• 제52권4호
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• pp.375-379
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• 2007

저장기간이 벼 생태형에 따라 미립 특성에 영향하는 정도를 검토하기 위하여 자포니카형, 통일형 및 통일형에서 유래된 1대잡종형의 정조를 $4{\sim}40$개월간 외부환경이 제어되지 않은 종자 저장실에 저장하여 저장기간에 따른 물리화학적 특성 변화에 대하여 조사한 결과는 다음과 같다. 1. 종자 발아율은 저장기간이 길어짐에 따라 낮아졌는데 자포니카형은 16개월 저장시 66.7%, 28개월 저장시 2.5%로 크게 떨어졌고 40개월 후에는 전혀 발아되지 않았으며, 통일형과 1대잡종형은 28개월까지는 뚜렷한 차이가 없었으나 40개월에는 각각 54.0% 및 67.9%로 발아율의 차이를 보였다. 2. 현미 경도는 통일형, 1대잡종형, 자포니카형의 순서로 높았으며 저장기간에 따른 유의한 차이는 없었다. 3. 알카리 붕괴도는 저장기간이 길어짐에 따라 증가하는 경향이었으며, 단백질 함량은 완만하게 감소하였고, 아밀로즈 함량은 일정한 경향이 없었다. 4. 전당 함량과 환원당 함량은 저장기간이 경과함에 따라 증가하였는데 저장 28 개월 이내에서 증가폭이 컷고 그 이후는 완만한 증가를 보였다. 5. 전당 함량에 대한 환원당 함량의 비율은 저장기간이 길수록 전당 함량보다는 환원당 함량의 증가가 많아서 비율이 높아졌다.

• 한국작물학회지
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• 제31권4호
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• pp.403-407
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• 1986

벼의 엽색은 시비시기를 결정하는데 주요한 인자로써 가시부 영역에서 해석하고, 이들 엽색을 지배하는 광합성색소는 T.L.C.로 분리하여 검토하였다. 1. 벼의 엽색은 413, 432, 453nm(청색부)와 662nm(적색부)에서 흡광되였고, 그 중에서 최대흡광은 432, 662 nm 이었다. 2. 양흡광도비(청색부/적색부)는 벼 생태형간에는 근 차이는 없었으나. 비료간에는 비료양이 증가할수록 적었다. 3. 양흡광도비와 엽색도 및 엽록소함량과는 부의 유의상관이 인정되었다. 4. 광합성색소 조성비율은 출수기에서는 녹색계통색소, 출수후 30일에는 황색계통색소의 조성비율이 각각 컸다. 5. 벼 생태형별 광합성색소율 Chl. a의 조성비율은 출수기에는 다수계품종이 일반계품종보다 컸고, 출수후 30일에는 일반계품종이 다수계품종보다 컸으나, carotene는 그 반대이었다.

• 한국잡초학회지
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• 제10권4호
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• pp.338-343
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• 1990

Echinochloa colona (L.) Link 생태형(生態型) 12종(種)의 제초제(除草劑)에 대한 종내(種內) 내성차이(耐性差異)를 생육(生育) 단계별(段階別) 검토(檢討)하였다. 발아(發芽) 및 발아후(發芽後) 생육(生育) 단계(段階)에서 Batangas 생태형(生態型)은 butachlor와 thiobencarb에 가장 큰 감수성(感受性)을 나타낸 반면, Bukidnon 생태형(生態型)은 가장 큰 내성(耐性)을 보였다. 그러난 생태형(生態型)들의 감수성 차이(差異)는 생태형(生態型)의 종자(種子) 무게 및 숙기(熟期)와는 상관성(相關性)이 없었다. 생태형(生態型)의 2엽기(葉基)에 제초제(除草劑)가 처리(處理)되었을 때, Nueva Ecija 생태형(生態型)은 butachlor 1 ppm에 가장 큰 내성(耐性)을 보였으냐, thiobencarb 1 ppm에 대하여서는 가 큰 감수성(感受性)을 나타내었다. 그러나 Cagayan 생태형(生態型)은 정반대(正反對)의 경향(傾向)을 보였다. 파종후(播種後) 20일(日)된 유묘(幼苗)의 제3엽(第3葉)에 처리된 propanil에 의한 necrosis 정도(程度)로 조사(調査)한 생태형(生態型)들의 감수성(感受性) 차이(差異)는 Camarines Sur, Iloilo 및 IRRI (red) 생태형(生態型)에서 현저(顯著)하였지만, Cagayan 및 Batangas 생태형(生態型)에서는 necrosis가 전혀 나타나지 않았다. 이러한 반응차이(反應差異)는 처리(處理)되는 제초제(除草劑)의 종류(種類)와 처리농도(處理濃度) 및 생태형(生態型)들의 생육단계(生育段階)에 따라 달랐다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2021년도 춘계학술대회
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• pp.23-23
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• 2021

• 한국농림기상학회지
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• 제3권1호
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• pp.55-70
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• 2001

It was unusual crop weather for 1998 and 1999 compared with normal in Korea. The consecutive days of the optimum ripening period for rice plant that had daily mean temperature 21~23$^{\circ}C$ for 40 days after flowering, increased with long anomalies in 1998~99. The air temperature during ripening period was much higher than the optimum temperature and lower sunshine hour than norm in the local adaptability tests of newly developed rice lines during those years. In response of rice cultivation to warming and cloudy weather during crop season, the yield shall be decreased. Most scientists agree that the rate of heating is accelerating and temperature change could become increasingly disruptive. Weather patterns should also become more erratic. Agrometeorologists could be analyzed yearly variations of temperature, sunshine hour and rainfall pattern focused on transient agroclimate change for last a decade. Rice agronomists could be established taking advantage of real time agricultural meteorology information system for fertilization, irrigation, pest control and harvest. Also they could be analyzed the characteristics of flowering response of the recommended and newly bred rice cultivars for suitable cropping plan such as cultural patterns and sowing or transplanting date. Rice breeders should be deeply considered introducing the characteristics of basic vegetative type of flowering response like Togil rices as prospective rice cultivars corresponding to global warming because of the rices needed higher temperature at ripening stage than japonica rices, photoperiod-sensitive and thermo-sensitive ecotypes.

• Journal of Photoscience
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• 제9권2호
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• pp.162-165
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• 2002

Rice is widely cultivated in various regions throughout Asia. Over a five-year period, we investigated the effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars in the field. The findings of that study indicated that supplemental UVB radiation has inhibitory effects on the growth and grain development. Furthermore, we investigated the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, and found that rice cultivars vary widely in UVB sensitivity. The aim of our study is improving UVB resistance in plants by bioengineering or breeding programs. In order to make it, there is need to find the molecular origin of the sensitivity to UVB. Cyclobutane pyrimidine dimer (CPD) is major UV-induced DNA lesions. Plants possess two mechanisms to cope with such DNA damage. The first is the accumulation of UV-absorbing compounds. Our previous data showed that the steady-state CPD levels in leaves of rice grown under chronic radiation in any culture were not so greatly influenced by the increased UV-absorbing compounds content, although there was a significant positive correlation between the CPD levels induced by challenge UVB exposure and the UV-absorbing compounds content. The other is the repair of DNA damage. Photorepair is the major pathway in plants for repairing CPD. We found that the sensitivity to UVB could seriously correlate with the low ability in CPD photorepair in rice plants. These results suggest that photo lyase might be an excellent candidate for restoration by way of selective breeding or engineering in rice.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1091-1095
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• 2009

The aim of this study investigated the fluctuations of 3 characters from 3 ecotypes [early ripening (ER), middle ripening (MR), and late ripening (LR)] of 20 Korean brown rice cultivars in different storage systems [time: 12 and 24 weeks, temperature: low ($10^{\circ}C$) and room ($25^{\circ}C$)]. With increase of storage time and temperature, lipoxygenase activity, and fat acidity increased, whereas germination rate was reduced. ER cultivars exhibited the highest lipoxygenase activity of $35.49{\pm}2.46$ unit/mg protein during 24 weeks storage at $25^{\circ}C$, followed by LR ($32.73{\pm}1.33$) and MR ($32.66{\pm}1.62$) cultivars. The amounts of fat acidity also were observed by the same order (ER: $20.40{\pm}2.12$>LR: $19.68{\pm}1.86$>MR: $19.64{\pm}1.35$ mg KOH/100 g). Germination rate slightly decreased with increase of time and temperature (MR>LR>ER), but MR and LR cultivars showed the most significant changes (ER: $60.90{\pm}23.47%$, MR: $32.66{\pm}13.95%$, and LR: $32.53{\pm}5.87%$). On the basis of above results, MR cultivars were evaluated the highest quality, because high lipoxygenase activity, high fat acidity, and low germination rate have deteriorated in quality and generated off-odor. Thus, MR cultivars might be very important sources in food processing and stored dietary supplement aspects.