출엽 및 최종엽수 추정에 의한 벼 발육 예측모델 개발

이변우 서울대학교 농업개발연구소 2001 농업생명과학연구 Vol.5 No.-

Under the constant daylength the final number of rrice leaves on the main culm(FNL) was constant regardless of temperature in rice variety 'Kwanganbyeo'. Leaf appearance rate(LAR) increased with rising temperature and decreased with phenological development. LAR was well fitted to the following model; dL/dt=(T_i-T_0)·(-a^-1·b^(1/c)·c·(a-L)^((c-1)/c)·L^((c+1)/c)) where dL/dt is LAR, t_i and T_0 are daily mean and threshold temperature, L is the number of leaves appeared, and a, b, and c are constants that were estimated as 41.8, 1098.38, and -0.9273 in Kwanganbyeo, respectively. FNL shoed very close relationship with the average daylength during photosensitive period(PSP) of six-leaf stage to panicle initiation, being well fitted to the following rational function(R^2=0.98); FNK=(a+bD)/(1+cD), where D is daylength and a, b, and c are the constants that wee estimated as 14.694, -0.992, and -0.068 in Kwanganbyeo, respectively. The rice phenology model, which was composed of the two component models for LAR and FNL, predicted developmental stage very accurately. The differences between the observed and predicted days to heading was less than two days in the sowing date field experiments in 1999 and 2000 of which data were not used for the model construction.

건답직파재배에서 요소 비료 시용시 벼의 질소 이용과 손실

이변우 서울대학교 농업개발연구소 1999 농업생명과학연구 Vol.3 No.-

The objectives of this study were to evaluate the loss and recovery of urea nitrogen applied at sowing as basal nitrogen and topdressed shortly after flooding at four- to six-leaf stage of rice, and the effectiveness of nitrogen split application method, a nitrification inhibitor, DCD (dicyandiamide), and a slow release fertilizer, latex-coated urea(LCU) on the nitrogen economy and yield performance of rice sown directly on dry paddy field. Urea applied at seeding was lost almost completely during dry paddy period of 20 to 30 days before permanent flooding. Plant recovery of nitrogen applied at sowing was only 2.5 to 3.2% with 91 to 96% loss during dry paddy period until 4-leaf stage, showing little year to year variation. Nitrogen loss due to ammonia volatilization covered only 1 to 11%, and the rest substantial part of loss appeared to be due to leaching and denitrification. Both leaching and denitification were important mechanisms of nitrogen loss during dry paddy period before permanent flooding. Urea topdressed shortly after flooding at four-leaf stage was utilized 8 to 40% by plant with 15 to 50% loss within 10 days after fertilization, being much less in N loss compared to urea applied at sowing. Nitrogen topdressed at this stage was lost primarily due to leaching at very early stage of fertilization because of very high rate of water percolation. Ammonia volatilization loss was very low, accounting only for below 2% of applied nitrogen. The data suggested that urea fertilization at sowing as basal fertilizer should be avoided or reduced to a minimum amount and the nitrogen alloted to basal fertilizer in conventional dry-seeding rice culture rather be supplemented to the topdressing shortly after permanent flooding at four to six-leaf stage of rice for improving nitrogen fertilization efficiency and rice yield. DCD increased slightly the plant recovery of fertilizer nitrogend and rice yield. However, such a degree of improvement might be achieved by other means of fertilization practice without chemical.

벼의 한계질소농도 결정 및 군락반사율을 이용한 질소영양상태 추정 연구

이변우 서울대학교 농업개발연구소 2000 농업생명과학연구 Vol.4 No.-

Critical nitrogen concentration(Nc) which is defined as the minimum nitrogen concentration to maintain the maximum growth rate at any time was investigated for rice plant. Based on Nc, nitrogen nutrition index(NNI) was calculated as its ratio to actual nitrogen concentration to examine the relationship with yield and yield components. In addition, investigated were the feasibilities to apply canopy reflectance measurements to diagnosing the nitrogen nutrition status nondestructively. Shoot critical nitrogen concentrations had no differences between rice varieties, Hwasungbyeo and Dasanbyeo, having the relationship with shoot dry weight(DW) as Nc=5.26DW-4.138(R2=0.966). This Nc dilution curve can be applied only in case that DW is greater than 1 to 1.5t/ha. For the early growth stage with DW less than 1 to 1.5t/ha, Nc should be determined with further detailed experiments. Nitrogen nutrition index(NNI), which is calculated as the ratio of Nc to actual N concentration, represented nitrogen nutrition status of rice very well. Showing the close relationship with rice yield and its components. Visible light reflectance had no great variations as LAI increases above 2. While near infra red(NIR) reflectance increased with LAI increase. Visible light reflectance decreased but NIR reflectance changed little with the increased nitrogen application levels. In cas of LAI less than 2, it was difficult to estimate canopy characteristics such as plant nitrogen concentration and NNI by canopy reflectance as the background reflectance of paddy soil and water contributed too much to canopy reflectance(ρ). Whereas, plant nitrogen concentration and NNI of rice canopy with LAI above 2 had very significant correlations with visible band reflectances, RVI, NDVI and so forth. Especially, RVIgreen(□) and NDVIgreen(□) showed the close linear regression relationship with NNI which had coefficients of determination of R2=0.802 and R2=0.845, respectively, indicating that these vegetation indexes could be used effectively to estimate NNI nondestructively. However, further studies to get rid of background effects on canopy reflectance are needed for the effective diagnosis of nitrogen nutrition status with canopy reflection measurements even in early growth stage with LAI below 2.

멀칭에 따른 지온변화 모델의 작성 및 토양온도의 추정

최일선,이변우 한국농림기상학회 1999 한국농림기상학회지 Vol.1 No.2

A numerical model using soil surface energy balance and soil heat flow equations to estimate mulched soil temperature was developed. The required inputs data include weather data, such as global solar radiation, air temperature, wind speed, atmospheric water vapor pressure, the optical properties of mulching material, and soil physical properties. The observed average soil temperature at 50 cm depth was used as the initial value of soil temperature at each depth. Soil temperature was simulated starting at 0 hour at an interval of 10 minutes. The model reliably described the variation of soil temperature with time progress and soil depth. The correlation between the estimated and measured temperature yielded coefficient values of 0.961, 0.966 for 5cm and 10cm depth of the bare soil, respectively, 0.969, 0.965 for the paper mulched soil, and 0.915, 0.938 for the black polyethylene film mulched soil. The percentages of absolute differences less than 2℃ between soil temperatures measured and simulated at 10 minute interval were 97.4% and 98.5% for 5 cm and 10cm for the bare soil, respectively, and 95.8% and 97.4% for the paper mulched soil, and 70.1% and 92.5% for the polyethylene film mulched soil. The results indicated that the model was able to predict the soil temperature fairly well under mulched condition. However, in the night time, the model performance was a little poor as compared with day time due to the difficulty of accurate determination of the atmospheric long wave radiation.

Kainic Acid로 유발된 경련이 흰쥐 대뇌피질의 Vasoactive Instestinal Polypeptide 신경세포에 미치는 영향에 관한 면역조직화학적 연구

허영범,변우현,이원규,김정혜,안희경 대한해부학회 1995 Anatomy & Cell Biology Vol.28 No.2

Three Newly Recorded Species of the Genus Olethreutes (Lepidoptera, Tortricidae) from North Korea

Bong-Kyu Byun,Bong-Woo Lee,Ha Yong Choi,Seung Jin Roh 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.10

In North Korea, the Tortricidae has been poorly studied until Byun et al. (1998) reviewed 350 species from Korea, including 63 species of Tortricinae and 40 species of Olethreutinae. Then Razowski (1999) presented a checklist of 358 species of Tortricidae from Korea, including 176 species of the North Korean Tortricidae with mostly based on the avaialble materials in Poland and previous literatures. Later, a serial studies on the family Tortricdae of North Korea with the material deposited in the Hungarian Natural History Museum provided several additional data for the North Korean tortricid fauna (Byun 2009; Byun 2011a; Byun 2011b; Byun 2011c; Byun et al. 2007) During the course of the study on the Tortricidae of North Korea deposited in Hungarian Natural History Museum, the author found three species of Olethreutes for the first time from North Korea. Of them, Olethreutes aviana Falkovitsh is also newly reported to the Korean peninsula. The aim of the present study is to report the three species of Olethreutes as new to North Korean fauna. In the present study, three species of the genus Olethreutes: O. aviana Falkovitsh, O. obovata (Walsingham), and O. orthocosma (Meyrick), based on the material deposited in the Hungarian Natural History Museum, are reported for the first time from North Korea. Among them, O. aviana Falkovitsh is recorded as new to the Korean peninsula. Photographs of the adults and genitalia of the species are presented.

Assessment of microclimate conditions under artificial shades in a ginseng field

Lee, Kyu Jong,Lee, Byun-Woo,Kang, Je Yong,Lee, Dong Yun,Jang, Soo Won,Kim, Kwang Soo The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.1

Background: Knowledge on microclimate conditions under artificial shades in a ginseng field would facilitate climate-aware management of ginseng production. Methods: Weather data were measured under the shade and outside the shade at two fields located in Gochang-gun and Jeongeup-si, Korea, in 2011 and 2012 seasons to assess temperature and humidity conditions under the shade. An empirical approach was developed and validated for the estimation of leaf wetness duration (LWD) using weather measurements outside the shade as inputs to the model. Results: Air temperature and relative humidity were similar between under the shade and outside the shade. For example, temperature conditions favorable for ginseng growth, e.g., between $8^{\circ}C$ and $27^{\circ}C$, occurred slightly less frequently in hours during night times under the shade (91%) than outside (92%). Humidity conditions favorable for development of a foliar disease, e.g., relative humidity > 70%, occurred slightly more frequently under the shade (84%) than outside (82%). Effectiveness of correction schemes to an empirical LWD model differed by rainfall conditions for the estimation of LWD under the shade using weather measurements outside the shade as inputs to the model. During dew eligible days, a correction scheme to an empirical LWD model was slightly effective (10%) in reducing estimation errors under the shade. However, another correction approach during rainfall eligible days reduced errors of LWD estimation by 17%. Conclusion: Weather measurements outside the shade and LWD estimates derived from these measurements would be useful as inputs for decision support systems to predict ginseng growth and disease development.

Reactive oxygen species-dependent activation of Bax and poly(ADP-ribose) polymerase-1 is required for mitochondrial cell death induced by triterpenoid pristimerin in human cervical cancer cells.

Byun, Joo-Yun,Kim, Min-Jung,Eum, Da-Young,Yoon, Chang-Hwan,Seo, Woo-Duck,Park, Ki Hun,Hyun, Jin-Won,Lee, Yun-Sil,Lee, Jae-Seong,Yoon, Moon-Young,Lee, Su-Jae American Society for Pharmacology and Experimental 2009 Molecular pharmacology Vol.76 No.4

<P>Naturally occurring triterpenoid compounds have long been used as anti-inflammatory, antimalarial, and insecticidal agents. It has become evident that some of the natural or synthetic triterpenoids have promising clinical potential as both a therapeutic and chemopreventive agent for cancer. However, the molecular basis for the antitumor activity of triterpenoid has yet to be defined. In this study, we show that pristimerin, a natural triterpenoid, induces mitochondrial cell death in human cervical cancer cells and that reactive oxygen species (ROS)-dependent activation of both Bax and poly(ADP-ribose) polymerase-1 (PARP-1) is critically required for the mitochondrial dysfunction. We also showed that c-Jun N-terminal kinase (JNK) is involved in ROS-dependent Bax activation. Treatment of pristimerin induced an increase in intracellular ROS, JNK activation, conformational change, and mitochondrial redistribution of Bax, mitochondrial membrane potential loss, and cell death. The PARP-1 was also found to be activated by pristimerin treatment. An antioxidant, N-acetyl-l-cysteine (NAC), inhibited pristimerin-induced JNK activation, Bax relocalization, and PARP-1 activation, as well as mitochondrial cell death. Moreover, inhibition of JNK clearly suppressed conformational change and mitochondrial translocation of Bax and subsequent mitochondrial cell death but did not affect PARP-1 activation. Inhibition of PARP-1 with 1,5-dihydroxyisoquinoline (DIQ) or with small interfering RNA of PARP-1 significantly attenuated pristimerin-induced mitochondrial membrane potential loss and cell death but did not affect JNK activation and Bax relocalization. These results indicate that the natural triterpenoid pristimerin induces mitochondrial cell death through ROS-dependent activation of both Bax and PARP-1 in human cervical cancer cells and that JNK is involved in ROS-dependent Bax activation.</P>

Relationship between Plastochrone and Development Indices Estimated by a Nonparametric Rice Phenology Model

Byun Woo Lee,Taeg Su Nam,Young Seon Yim 韓國作物學會 1999 Korean journal of crop science Vol.44 No.2

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.

Relationship between Plastochrone and Development Indices Estimated by a Nonparametric Rice Phenology Model

Lee, Byun-Woo,Nam, Taeg-Su,Yim, Young-Seon The Korean Society of Crop Science 1999 Korean journal of crop science Vol.44 No.2

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.