• Title/Summary/Keyword: Early maturing rice

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Allelic Distribution of OsPRR37, a Major Heading Date Gene in Korean Rice Cultivars

  • Hayeong Lee;Yurim Kim;Jiheon Han;Sieun Choi;Yeeun Jun;Hosun Chun;Soonhwa Kwak;Youngjun Mo
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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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.

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Optimum N-fertilization Level for Quality Rice Production in the Southern Alpine Area of Korea (남부 산간고랭지에서 쌀 품질 향상을 위한 적정 질소시비량)

  • Kim, Sang-Su;Choi, Weon-Young;Nam, Jeong-Kwon;Lee, Jun-Hee;Back, Nam-Hyun;Park, Hong-Kyu;Choi, Min-Kyu;Kim, Chung-Kon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.spc1
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    • pp.30-34
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    • 2006
  • The effect of N-fertilization on yield, milling characteristics and quality of Samcheonbyeo, an early maturing rice variety, was investigated in 2002 to 2004. The study was carried out in the southern alpine area of Un-bong Sub-Station, Honam Agricultural Research Institute. Higher nitrogen levels increased number of panicle and grain per unit area, but lowed ripening rate and decreased 1,000-grain weight. Higher nitrogen levels of up to 90 kg/ha also increased head rice yield. A nitrogen level of 90 kg/ha was found optimal for increasing ripening rate and head rice yield, and rice palatability.

Comparison of Methane Emissions by Rice Ecotype in Paddy Soil

  • Tae Hee Kim;Jisu Choi;Seo Young Oh;Seong Hwan Oh
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.145-145
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    • 2022
  • South Korea greenhouse gas emissions have increased year by year, resulting in a total emission of 727.6 million tons of CO2 eq in 2018, a 2.5% increase compared to 2017. Among them, the agricultural sector emitted 21.2 million tons of CO2 eq., accounting for 2.9% of the total. Among the greenhouse gases emitted from the agricultural sector, a particularly problematic is methane gas emitted from rice paddies. Methane is one of the important greenhouse gases with a global warming potential (GWP) that is about 21 times higher than that of carbon dioxide due to its high infrared absorption capacity despite its relatively short remaining atmospheric period. Since the pattern of methane generation varies depending on the rice variety and ecological type, research related to this is necessary for accurate emission calculation and development of reduction technology. Accordingly, a study was conducted to find out the changes in greenhouse gas emission according to rice varieties and ecology types. As for the rice eco-type cultivar, early maturing cultivar (Haedamssal) and medium-late rice cultivar (Saeilmi) were used. Haedamssal was transplanted on May 25 and June 25, and Saeilmi was transplanted on June 10 and June 25. The amount of methane generated according to the growing day showed a tendency to increase as the planting period was earlier. The difference between varieties was that Haedamssal showed higher methane production than Saeilmi. The total CH4 flux in the saeilmi was 18.7 kg·h-1(Jun 10 transplanting), 12.4 kg·h-1(Jun 25 transplanting) during rice cultivation. Lower methane emission was observed in Saeilmi than in Haedam rice. In addition, the earlier the planting period, the higher the methane emission. This study is the result of the first year of research, and it is planned to investigate the amount of greenhouse gas emission between double cropping and single cropping using wheat cultivation after harvest for each ecological type.

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Effect of Seeding Times on Growth and Yield of Rice in Puddled Drill Seeding at Southern Plain Area (남부평야지 벼 무논 골뿌림 재배시 파종시기가 생육 및 수량에 미치는 영향)

  • Kim, Sang-Su;Baek, Nam-Hyun;Seok, Soon-Jong;Lee, Seon-Yong;Cho, Dong-Sam
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.2
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    • pp.212-220
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    • 1995
  • The optimum seeding date and the suitable seeding period for puddled drill seeding of rice at southern plain area were determined by using Sinunbongbyeo (early maturing variety), Hwaseongbyeo(medium maturing var.) and Dongjinbyeo (late medium maturing var.) at National Honam Agricultural Experiment Station from 1993 to 1994, Seedling stand was decreased significantly at seeding on April 25 in all varieties, Threshold seed-ing dates for stable ripening was estimated as June 10 in Sinunbongbyeo, May 31 in Hwaseongbyeo and May 25 in Dongjinbyeo, The 1,000 grain weight and the ripened grain rate were highest at seed-ing on May 10 or May 25 in all varieties, and decreased significantly at seeding on June 25 in Sinunbongbyeo and seeding after June 10 in Hwaseongbyeo and Dongjinbyeo, The optimum average air temperature for 40 days after heading was 22.6$^{\circ}C$ for highest ripening rate and 22.0$^{\circ}C$ for heaviest 1,000 grain weight. The optimum seeding date for highest yield was May 9 in Dongjinbyeo, May 13 in Hwaseongbyo and May 15 in Sinunbongbyeo.

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Occurrence of Upper Node Tiller in the Rice Varities (벼 품종의 상위절 분얼 발생양상)

  • 박경배;이성환
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.1
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    • pp.5-9
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    • 1987
  • In order to investigate the occurrence status of tiller at the upper node of rice, this trial was conducted with different eco-typed and 23 cultivars in 1983 and testified the effect of fertilizer levels with Indica x Japonica cultivars in 1984. In occurring of tiller at the upper nodes, upper 2nd, 3rd node and lower 2nd, 3rd node rose simultaneously. The tillering rates of the upper nodes of Japonica x Indica cultivars were more than Japonica cultivars and early maturing cultivars were more than medium or late maturing cultivars, respectively. Highly negative correlations were found between the tillering rate of upper nodes and days from transplant-ing to heading and bending angle degree of 2nd node. The tilleriiig rate of the upper nodes treated with different levels of fertilizer increased with non-fertilizer than those of standard (N-P-K =15-11-13kg/10a) or heavy (N-P-K =25-15-18kg/10a) levels.

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Estimation of Rice Canopy Leaf Area Index(LAI) by Spectral Reflectance of Solar Radiation in Paddy Field (태양광 반사율을 이용한 벼 군락의 엽면적지수 추정)

  • 이정택;이춘우;주문갑;홍석영
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.2
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    • pp.173-181
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    • 1997
  • To estimate the leaf area index(LAI) of rice plant by non-destructive method, spectral reflectance from rice plant canopy was measured by using the spectroradiometer (LI-1800, LICOR Inc.) with one week interval during the rice growing season at Suwon paddy field in 1993. LAI of two medium late maturing varieties, Daechungbyeo and Ilpumbyeo, and one early maturing variety, Jinbubyeo, were observed and compared with those estimated by vegetation index. The reflectance(R) of visible wavelength remained less than 0.1 over entire growing season, but that of near infrared wavelength remained from 0.1 to 0.5 with the significant positive correlation with LAI. Vegetation index determined by the reflectance of visible against near infrared wavelength showed high correlation with LAI of rice canopy. Vegetation index derived from wide band ratio, NIR(720~1, 100nm) /Blue(400~500nm), showed the highest correlation coefficient with LAI. Vegetation index derived from narrow band(10nm interval) ratio, R910/R460, from transplanting to heading stage corresponded well to measured values (Y=0.16799X-0.79776 ; $R^2$=0.94). But another vegetation index, NIR(720~1, 100nm) /Red (600~700nm), showed higher correlation with LAI than NIR /Blue did from heading stage to maturity.

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Effects of Nitrogen Level and Defoliation at Maturing Stage on the Yield Components of Rice (질소시용량(窒素施用量) 및 등숙기(登熟期) 절엽처리(切葉處理)가 수도수량구성요소(水稻收量構成要素)에 미치는 영향(影響))

  • Ahn, Su-Bong;Lee, Jong-Chul
    • Korean Journal of Agricultural Science
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    • v.4 no.1
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    • pp.26-33
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    • 1977
  • We have studied the responce of nitrogen on the newly bred varieties, Yusin and Milyang #23, and the effects of defoliation at maturing stage on the rate of ripened grains under different nitrogen levels. The results obtained are summarized as follows : 1. Milyang #23 as well as Tongil was found to be highly nitrogen responsive variety and showed good grain maturing percentage. The number of grain per unit area affected the total yield under the high levels of nitrogen application. The variety, Yusin, was less responsive to nitrogen and had also less leaf area than other varieties under the high level of nitrogen application. Yusin also seemed to have low maturing percentage due to unbalanced ratio between photosynthetic area and size of storage. 2. The low internodes and leaf blade of Yusin and Milyang #15 were grown too much under high levels of nitrogen and these caused more lodging and less light penetration in pant canopy. 3. The effects of defoliation at maturing stage on yield was high under the high levels of nitrogen application, especially when defoliation was done early stage of maturing. The effects of defoliation appeared to be greates in Tongil than in Milyang #15.

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Genotypic Differences in Yield and Yield-related Elements of Rice under Elevated Air Temperature Conditions (온도 조건에 따른 벼 수량 및 수량 관련 요소 반응의 품종간 차이)

  • Lee, Kyu-Jong;Kim, Dong-Jin;Ban, Ho-Young;Lee, Byun-Woo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.306-316
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    • 2015
  • An experiment in a controlled environment was conducted to evaluate the genotypic differences of grain yield and yield-related elements of rice under elevated air temperature. Eight rice genotypes included in three maturing group (early, medium, and medium-late maturing group) were grown with 1/5,000 a Wagner pots at four plastic houses that were controlled to the temperature regimes of ambient temperature (AT), $AT+1.5^{\circ}C$, $AT+3.0^{\circ}C$, and $AT+5.0^{\circ}C$ throughout the rice growing season in 2011. Ripened grain ratio and 1000 grain weight showed the most susceptible and tolerant responses to elevated air temperature, respectively. The grain yield reduction was attributable to the sharp decrease of ripened grain ratio. Grain yield was significantly decreased above the treatment of $AT+1.5^{\circ}C$ and $AT+3.0^{\circ}C$ in early maturing group and the others, respectively. Highly correlation to average temperature from heading to 20 days was revealed in yield (r = -0.69), ripened grain ratio (r = -82), fully-filled grain (r = -70), and 1000 grain weight (r = -0.31). The responses of yield and yield-related elements except number of spikelets and panicle to elevated air temperature were fitted to a logistic function. The parameters of logistic function for each elements except grain yield could not be applied to the other varieties. In conclusion, yield and yield-related elements responded differentially to elevated air temperature according to maturity groups and rice varieties. Ongoing global warming is expected to decrease the grain yield not only by decreasing the grain weight but also decreasing the ripened grain ratio in the future. However, the yield reduction would be mitigated by adopting and/or breeding the less sensitive varieties to high temperature.

Effects of Forage-Rice Cropping Systems on the Growth and Grain Quality of Early Maturing Rice Cultivars and Soil Chemical Properties in Paddy Fields in Southern Korea (사료작물-벼 작부체계가 조생종 벼의 생육과 미질 특성 및 토양의 화학적 특성에 미치는 영향)

  • Oh, Seo Young;Oh, Seong Hwan;Seo, Jong Ho;Choi, Jisu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.66 no.4
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    • pp.297-306
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    • 2021
  • To select rice (Oryza sativa L.) cultivars suitable for forage-rice double cropping system, the growth and grain quality of four early maturing rice cultivars (Joun, Jopyeong, Haedamssal, and Unkwang), and the chemical properties of soils were investigated under single- (fallow-rice) and forage-rice double-cropping systems in paddy fields in Miryang, southern Korea. The soil where two forage crops [Italian ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.)] were cultivated during winter had a slightly lower pH; an increase in total nitrogen (T-N), K, Ca, and Na contents; and a slight decrease in organic matter and available P2O5 contents, compared with the soil fallowed during winter. This shows that the chemical properties of paddy soils can be improved by winter forage cropping. At the heading stage, the culm length, panicle length, panicle number, and leaf color of all cultivars, except for Haedamssal, were generally higher under double-cropping than under single-cropping. For Haedamssal, the culm length and leaf color did not differ between the cropping systems, but the panicle length was slightly shortened and its panicle number increased under double-cropping. After harvest, the yield of milled rice decreased for all cultivars except Haedamssal, but increased in Haedamssal under double-cropping. The head rice rate was slightly higher under double cropping, particularly in Jopyeong and Haedamssal, than under single-cropping. The protein content of milled rice under double cropping was higher and its amylose content was similar or slightly lower compared to those of rice under single cropping, resulting in decreased Toyo values for rice under double-cropping. The pasting temperature did not differ significantly between the cropping systems. However, Haedamssal had a low pasting temperature but a high Toyo value under double cropping, compared to the other three cultivars, suggesting that its palatability is relatively high. Furthermore, panicle number increased and milled rice yield did not decrease, even under double cropping. Therefore, Haedamssal seems to be the best cultivar for paddy-based double cropping with forage crops.

Impacts of Climate Change on Rice Production and Adaptation Method in Korea as Evaluated by Simulation Study (생육모의 연구에 의한 한반도에서의 기후변화에 따른 벼 생산성 및 적응기술 평가)

  • Lee, Chung-Kuen;Kim, Junwhan;Shon, Jiyoung;Yang, Woon-Ho;Yoon, Young-Hwan;Choi, Kyung-Jin;Kim, Kwang-Soo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.4
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    • pp.207-221
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    • 2012
  • Air temperature in Korea has increased by $1.5^{\circ}C$ over the last 100 years, which is nearly twice the global average rate during the same period. Moreover, it is projected that such change in temperature will continue in the 21st century. The objective of this study was to evaluate the potential impacts of future climate change on the rice production and adaptation methods in Korea. Climate data for the baseline (1971~2000) and the three future climate (2011~2040, 2041~2070, and 2071~2100) at fifty six sites in South Korea under IPCC SRES A1B scenario were used as the input to the rice crop model ORYZA2000. Six experimental schemes were carried out to evaluate the combined effects of climatic warming, $CO_2$ fertilization, and cropping season on rice production. We found that the average production in 2071~2100 would decrease by 23%, 27%, and 29% for early, middle, and middle-late rice maturing type, respectively, when cropping seasons were fixed. In contrast, predicted yield reduction was ~0%, 6%, and 7%, for early, middle, and middle-late rice maturing type, respectively, when cropping seasons were changed. Analysis of variation suggested that climatic warming, $CO_2$ fertilization, cropping season, and rice maturing type contributed 60, 10, 12, and 2% of rice yield, respectively. In addition, regression analysis suggested 14~46 and 53~86% of variations in rice yield were explained by grain number and filled grain ratio, respectively, when cropping season was fixed. On the other hand, 46~78 and 22~53% of variations were explained respectively with changing cropping season. It was projected that sterility caused by high temperature would have no effect on rice yield. As a result, rice yield reduction in the future climate in Korea would resulted from low filled grain ratio due to high growing temperature during grain-filling period because the $CO_2$ fertilization was insufficient to negate the negative effect of climatic warming. However, adjusting cropping seasons to future climate change may alleviate the rice production reduction by minimizing negative effect of climatic warming without altering positive effect of $CO_2$ fertilization, which improves weather condition during the grain-filling period.