• Research Article

    Effects of Ripening Temperature on Starch Structure and Storage Protein Characteristics of Early Maturing Rice Varieties during Grain Filling

    조생종 벼의 평야지 재배에 따른 등숙 온도 차이에 의한 전분구조 및 종자 저장단백질 특성 연구

    Jieun Kwak, Jeom-Sig Lee, Yong-Jae Won, Hyang-Mee Park, Kang-Su Kwak, Mi-Jung Kim, Choon-Ki Lee, Sun-Lim Kim, and Mi-Ra Yoon

    곽지은, 이점식, 원용재, 박향미, 곽강수, 김미정, 이춘기, 김선림, 윤미라

    This study was performed to understand the effects of filling stage temperature on the characteristics of starch and storage protein and the ... + READ MORE
    This study was performed to understand the effects of filling stage temperature on the characteristics of starch and storage protein and the quality of rice grains. Eight early maturing rice varieties were cultivated in Cheolweon (latitude 38°15’N) and Suwon (latitude 37°16’N) areas in Korea. Rice grown in Suwon, with relatively high ripening period temperatures, showed significantly reduced head rice ratio and eating qualities, higher protein and lower amylose contents than rice grown in Cheolweon. In rice that ripened under high temperature conditions, the starch contained significantly less short-chain amylopectin (DP < 12) but more intermediate- (DP 13-24) and long- (DP > 25) chain amlylopectin compared to rice that ripened under normal conditions. In addition, the electrophoretic pattern of rice storage protein under high- temperature conditions revealed decreased prolamin and increased glutelin contents. - COLLAPSE
    June 2018
  • Research Article

    Effects of Low Temperature during Ripening on Amylose Content and Enzyme Activities Associated with Starch Biosynthesis in Rice Endosperm
    Jung-sun Baek, Han-Yong Jeong, Sung-Hyun An, Jae-Heok Jeong, Hyen-Seok Lee, Jong-Tak Yoon, Kyung-Jin Choi, and Woon-Ha Hwang
    The objective of this study was to determine the effects of low temperature on starch accumulation in rice grains. We used four ... + READ MORE
    The objective of this study was to determine the effects of low temperature on starch accumulation in rice grains. We used four major Japonica-type Korean rice cultivars as materials: Jinbu (JB), Junamjosaeng (JJ), Geumyoung (GY), and Hwawang (HW). Rice plants were moved into two phytotrons the day after heading. Temperatures in the two phytotrons were maintained at 19/29℃ (night/day) as the control, and 13/23℃ as the low temperature condition, both under natural daylight with a relative humidity of 65%. The ripening rates of JB and JJ showed no significant difference between the low temperature and control conditions at 45 days after heading (DAH). In contrast, the ripening rates of GY and HW were 86% and 57% lower than those of JB and JJ under the low temperature condition at 45 DAH, respectively. However, the ripening rates of these four varieties at 61 DAH (when accumulated temperature reached 1,100℃) under the low temperature condition were similar to those at 45 DAH under the control condition (JB, 94%; JJ, 97%; GY, 97%; HW, 88%). The total starch contents showed no significant difference between the control and low temperature conditions. However, the amylose contents in the cultivars were higher under the low temperature than under the control condition. The enzyme activities of starch biosynthesis were about 5–10 days slower in cultivars under the low temperature than under the control. The grain-filling rate showed significant correlations with the enzyme activities of SuSase (r2=0.70***), AGPase (r2=0.63***), UDPase (r2=0.36***), StSase (r2=0.51***), and SBE (r2=0.59***). In conclusion, although StSase activity was increased at 13/23℃ up to 20 DAH, there might not be enough time for SBE to synthesize amylopectin, thus affecting the amylose content of HW, which had the slowest grain filling rate. Notably, the decreased activity of SuSase and SBE and late increase in AGPase activity under the low temperature during the ripening stage are considered to be disadvantageous, as they delay ripening and increase the amylose content. - COLLAPSE
    June 2018
  • Research Article

    Identification of New, Old and Mixed Brown Rice using Freshness and an Electronic Eye

    신선도와 전자눈을 이용한 현미 신곡, 구곡 및 혼합곡의 판별

    Jee-Hwa Hong, Young-Jun Park, Hyun-Tae Kim, and Sang Kyun Oh

    홍지화, 박영준, 김현태, 오상균

    The sale of brown rice batches composed of rice produced in different years is prohibited in Korea. Thus, new methods for the ... + READ MORE
    The sale of brown rice batches composed of rice produced in different years is prohibited in Korea. Thus, new methods for the identification of the year of production are critical for maintaining the distribution of high quality brown rice. Here, we describe the exploitation of an enzyme that can be used to discriminate between freshly harvested and one-year-old brown rice. The degree of enzyme activity was visualized through freshness test with Guaiacol, Oxydol, and p-phenylenediamine reagents. With electronic eye equipment, we selected 29 color codes for identifying new brown rice and old brown rice. The discrimination power of selected color codes showed a minimum of 0.263 to a maximum of 0.922 and an average value of 0.62. The accuracy with which new brown rice and old brown rice could be identified was 100% in principal component analysis (PCA) and discriminant function analysis (DFA). The DFA analysis had greater discriminatory power than did the PCA analysis. A verification test using new brown rice, old brown rice, or a mixture of the two was then performed to validate our method. The accuracy of identification of new and old brown rice was 100% in both cases, whereas mixed brown rice samples were correctly classified at a rate of 96.9%. Additionally, in order to test whether the discriminant constructed in winter can be applied to samples collected in summer, new and old brown rice stored for 8 months were collected and tested. Both new and old brown rice collected in summer were classified as old brown rice and showed 50% identification accuracy. We were able to attribute these observations to changes in enzyme content over time, and therefore we conclude, it will be necessary to develop discriminants that are specific to distinct storage periods in the near future. - COLLAPSE
    June 2018
  • Research Article

    Evaluation of the Fermentation Ability of Lactic Acid Bacteria to Manufacture Highest Quality Rice Straw Silage

    고품질 볏짚 사일리지 제조를 위한 다양한 유산균주 평가

    In-Sok Lee, Song-Yee Lee, Min-Kyung Choi, Chan-Ho Kang, and Jeong-Man Kim

    이인석, 이송이, 최민경, 강찬호, 김정만

    The main objective of this study was to determine the quality of rice straw silage made with various lactic acid bacteria (LAB) ... + READ MORE
    The main objective of this study was to determine the quality of rice straw silage made with various lactic acid bacteria (LAB) during fermentation. Five strains of LAB (Lactobacillus plantarum CMRT, L. leuconostoc mesenteroides M17, L. sakei C11, M5, SP2) were used in this study. With regard to odor, ready-made CMRT (a comparison strain) had the highest value from 10-60 days, followed by M17. The pH level of all silages made with five strains (apart from CMRT) ranged from 4.02 to 4.59. Of these, M17 rapidly lowered the pH value in the silage. Crude protein (CP) content was significantly lower (p < 0.01) in ready-made CMRT compared to the other bacteria. C11 fermentation produced the highest content of silage, with a score of 5.56. Acetic acid and butyric acid were not detected in any of the silage products. The lactic acid levels in silages produced by M17, M5, C11, and SP2 were comparatively higher than that produced by CMRT. The total digestible nutrient (TDN) content levels and relative fees value (RFV) were he highest in the silage of C11 (69.65 and 155.56, respectively), followed by M17. Based on odorl, pH, protein, organic acid, and feed value, we suggest tha the M17 strain is a suitable substitute for CMRT that can be used to generate high quality rice straw silage. - COLLAPSE
    June 2018
  • Research Article

    Ripening Characteristics and Antioxidant Enzyme Activity of Ilmi under Heat Stress Condition
    Woon-Ha Hwang, Jae-Hyeok Jeong, Hyeon-Seok Lee, In-Bae Choi, Seung-Hyeon Ahn, Han-Young Jeong, Jong-Tak Yoon, and Kyung-Jin Choi
    Heat stress during the ripening stage reduces the yield and quality of rice. Considering the adverse effects of global warming, it is ... + READ MORE
    Heat stress during the ripening stage reduces the yield and quality of rice. Considering the adverse effects of global warming, it is necessary to breed heat stress tolerant rice cultivars and analyze their stress tolerance characteristics. We investigated the ripening characteristics and antioxidant enzyme activity of Ilmi under heat stress condition during the ripening stage. Ripening rate, 1000 brown grain weight, and rice quality of Ilmi were not significantly changed by heat stress during the ripening stage. Leaf chlorophyll, chlorophyll a/b ratio, and malondialdehyde (MDA) contents of Ilmi leaves were also less changed than those of Ilpum. These results strongly suggested that Ilmi has heat tolerance characteristics during the ripening stage. Analysis of antioxidant enzyme activity of Ilmi revealed that peroxidase (POX) activity was significantly higher than that of Ilpum, and showed a significant correlation with the change in chlorophyll a/b ratio and hydrogen peroxide content of flag leaves of Ilmi. These data suggest that the high POX enzyme activity of Ilmi could be considered one of its major heat tolerance characteristics. - COLLAPSE
    June 2018
  • Research Article

    Association of Grain Filling Duration and Leaf Activity with the Grain Yield in Field-Grown Temperate Japonica Rice
    Woonho Yang, Shingu Kang, Jeong-Hwa Park, Sukjin Kim, Jong-Seo Choi, and Sunggi Heu
    Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during ... + READ MORE
    Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during the grain filling period to an appropriate environment plays a key role in achieving a high grain yield in temperate rice. Field experiments were conducted for two consecutive years with two planting times to assess the relations among grain filling traits, loss of leaf activity during the ripening period, and the grain yield of temperate japonica rice with wide environmental variation. Higher grain yields were attained in 2017 than in 2016 and with late planting than with early planting. The high grain yield accompanied a comparatively lesser increase in grain weight at the early filling stage but more gain in grain weight occurred during the late filling stage. Final grain weight correlated positively with grain filling duration but negatively with grain filling rate. Extended grain filling duration was associated with higher cumulative temperature and cumulative solar radiation for an effective grain filling period. The reduction in SPAD value × leaf dry weight from heading to harvest significantly correlated with final grain dry weight in a positive manner. No significant relation was found between grain filling duration and the decrease in SPAD value × leaf dry weight during the grain filling period. The results suggest that grain filling duration and loss of leaf activity during ripening independently contribute to environmentally induced yield improvement in temperate japonica rice. - COLLAPSE
    June 2018
  • Research Article

    Identification and Quantification of Phytosterols in Maize Kernel and Cob

    옥수수 종실 및 속대의 Phytosterol 동정과 함량 변이

    Sun-Lim Kim, Mi-Jung Kim, Gun-Ho Jung, Yu-Young Lee, Beom-Young Son, Jung-Tae Kim, Jin-Seok Lee, Hwan-Hee Bae, Young-Sam Go, Sang-Gon Kim, and Seong-Bum Baek

    김선림, 김미정, 정건호, 이유영, 손범영, 김정태, 이진석, 배환희, 고영삼, 김상곤, 백성범

    Unsaponifiables in the kernel and the cob of 7 maize varieties were analyzed by using thin-layer chromatography (TLC) and gas chromatography (GC) ... + READ MORE
    Unsaponifiables in the kernel and the cob of 7 maize varieties were analyzed by using thin-layer chromatography (TLC) and gas chromatography (GC) for the identification of phytosterols and their concentrations. The unsaponifiables of the kernel were clearly separated into band I (campesterol, stigmasterol, and β-sitosterol), band Ⅱ (Δ5-avenasterol), band Ⅲ (Δ7- stigmastenol), and band Ⅳ (Δ7-avenasterol). In the cob, on the other hand, three or more bands were separated in addition to bands. The GC analysis of unsaponifiables showed good separation of campesterol, stigmasterol and β-sitosterol, but the mixture of Δ7- avenasterol (retention time[RT] 22.846), Δ7-stigmastenol (RT 22.852), and Δ5-avenasterol (RT 22.862) showed poor separation. Phytosterol content of the maize kernel was 635.9 mg/100 g, and that of the cob was 273.0 mg/100 g, respectively. The phytosterol content of the kernel was 2.4-fold higher than that of the cob. The phytosterol content of the kernel was higher in the order β- sitosterol 80.05% > campesterol 10.5% > stigmasterol 9.46%, but that of the cob was higher in the order β-sitosterol 59.43% > stigmasterol 31.72% > campesterol 10.98%. Based on these results, it appears that the phytosterols of the maize kernel are synthesized in the maize cob and are transferred to the kernel, because the precursors (Δ7-avenasterol, Δ7-stigmastenol, and Δ5- avenasterol) of major phytosterols were detected in maize cobs. - COLLAPSE
    June 2018
  • Research Article

    Effects of Hydrogen Peroxide on Germination and Early Growth of Sorghum (Sorghum bicolor)

    과산화수소 처리가 수수의 발아 및 초기 생장에 미치는 효과

    Doobo Shim, Ki Eun Song, Chan Young Park, Seung Ho Jeon, Jung Gyu Hwang, Eun-ju Kang, Jong Cheol Kim, and Sangin Shim

    심두보, 송기은, 박찬영, 전승호, 황정규, 강은주, 김종철, 심상인

    As the global warming causing desertification increase, there is growing concern about damage of crops. It was to investigate how the treatment ... + READ MORE
    As the global warming causing desertification increase, there is growing concern about damage of crops. It was to investigate how the treatment with hydrogen peroxide before leaf development affects the growth and yield of sorghum for minimizing a damage of crops to drought. The germination experiment was conducted at alternating temperature of 25℃/20℃(12 hr/12 hr) under water stress condition of 0 ~ -0.20 MPa adjusted with PEG solution containing 0 and 10 mM H2O2. In order to know the effect of foliar application of hydrogen peroxide on the growth of sorghum, 10 mM hydrogen peroxide was treated to leaves at 3-leaf stage of sorghum growing in greenhouse conditions. Seed germination rate was increased by 20% in hydrogen peroxide treatment as compared to the Control. under water stress conditions (-0.15 ~ -0.20 MPa). The length of seedlings was also on the rise by the hydrogen peroxide treatment. In the greenhouse pot experiment, the morphological characteristics (plant height, stem diameter, leaf length, and leaf number) and physiological characteristics (chlorophyll content, chlorophyll fluorescence (Fv/Fm), stomatal conductance) were higher in the plants treated with hydrogen peroxide under the drought stress condition than those of plants of H2O treatment. Experiment conducted with the soil moisture gradient system showed that the foliar application of hydrogen peroxide increased photosynthetic ability of sorghum plant with respect to SPAD value and stomatal conductance and rooting capacity (root weight and root length) under drought condition. Generally, hydrogen peroxide treatment in sorghum increased the tolerance to drought stress and maintained better growth due to ameliorating oxidative stress. - COLLAPSE
    June 2018
  • Research Article

    Changes in Functional Compounds and Antioxidant Activities in Storage Duration with Accelerated Age-Conditioning of Oats

    노화가속화 조건에서 저장 기간에 따른 귀리의 기능성 성분 및 항산화 활성 변화

    Yu Rim Son, Ji Hae Lee, Hyoung-Ho Park, Byong Won Lee, Hyun-Joo Kim, Sang-Ik Han, Koan Sik Woo, Byoung-kyu Lee, Sang-Chul Lee, and Yu Young Lee

    손유림, 이지혜, 박형호, 이병원, 김현주, 한상익, 우관식, 이병규, 이상철, 이유영

    In this study, we investigated the changes in physicochemical properties, antioxidant activities, and contents of functional compounds, such as avenanthramides (AVNs), vitamin ... + READ MORE
    In this study, we investigated the changes in physicochemical properties, antioxidant activities, and contents of functional compounds, such as avenanthramides (AVNs), vitamin E, and β-glucan, in oats by accelerated age-conditioning (temperature: 45℃, relative humidity: 20%). No significant differences were observed in crude protein, crude fat, and AVNs contents of three oat cultivars, up to 63 days of storage; however, their antioxidant activities, as well as β-glucan, vitamin E, and fatty acid contents were significantly different (p < 0.05). β-glucan and fatty acid contents and the antioxidant activities of Deayang (DY) cultivar did not change during storage. β-glucan and unsaturated fatty acid contents of Choyang (CY) and Jopung (JP) increased during the storage period, while antioxidant activities did not (DPPH-CY; 48.1 to 26.9 mg TEAC/100 g, JP; 49.4 to 26.7 mg TEAC/100 g. ABTS-CY; 88.4 to 56.3 mg TEAC/100 g, JP; 80.0 to 55.8 mg TEAC/100 g). The total vitamin E content in DY (1.20 to 0.85 mg/100 g) and CY (1.73 to 1.33 mg/100 g) decreased, but it was maintained in JP. This study indicated that the changes in physicochemical properties and functional compounds of oat grains during storage depends on the cultivars. The result showed that DY, which has the highest AVNs content, has more stable functional compounds and antioxidant activities during storage. These results can serve as essential data for post-harvest management and development of functional food materials for extending the use of oats. - COLLAPSE
    June 2018
  • Research Article

    Estimation of Oil Yield of Perilla by Seed Characteristics and Crude Fat Content
    Eunyoung Oh, Myoung Hee Lee, Jung In Kim, Sungup Kim, Suk-Bok Pae, and Tae Joung Ha
    Perilla (Perilla frutescens var.frutescens) is an annual plant of the Lamiaceae family, mainly grown for obtaining oil by press extraction after roasting ... + READ MORE
    Perilla (Perilla frutescens var.frutescens) is an annual plant of the Lamiaceae family, mainly grown for obtaining oil by press extraction after roasting the seeds. Oil yield is one of its important traits, but evaluating this yield is time-consuming, requires many seeds, and is hard to adjust to pedigrees in a breeding field. The objective of this study was to develop a method for selecting high-oil-yield lines in a breeding population without oil extraction. Twenty-three perilla cultivars were used for evaluating the oil yield and seed traits such as seed hardness, seed coat thickness, seed coat proportion and crude fat. After evaluation of the seed traits of 23 perilla cultivars, the ranges of oil yields, seed hardness, seed coat thickness, seed coat proportion, 100-seed weight, and crude fat were 24.68-38.75%, 157-1166 gf, 24-399 ㎛, 15.4-41.5%, 2.79-6.69 g, and 33.0-47.8%, respectively. In an analysis of correlation coefficients, the oil yield negatively correlated with seed length, seed width, the proportion of seed coat, seed hardness, and 1000-seed weight, but positively correlated with crude fat content. It was observed that as the seed coat proportion increased, the seed coat thickness, hardness, and 1000-seed weight also increased. Multiple linear regression (MLR) was employed to find major variables affecting the oil yield. Among the variables, traits crude fat content and seed coat proportion were assumed to be indirect parameters for estimating the potential oil yield, with respect to a significant positive correlation with the observed oil yield (R2 = 0.791). Using these two parameters, an equation was derived to predict the oil yield. The results of this study show that various seed traits in 23 perilla cultivars positively or negatively correlated with the oil yield. In particular, crude fat and the seed coat proportion can be used for predicting the oil yield with the newly developed equation, and this approach will improve the efficiency of selecting prominent lines for the oil yield. - COLLAPSE
    June 2018
  • Research Article

    Impact of Elevated Carbon Dioxide, Temperature, and Drought on Potato Canopy Architecture and Change in Macronutrients

    상승된 이산화탄소와 온도 그리고 한발 영향에 따른 감자의 군락 형태와 무기영양 변화

    Yun-Ho Lee, Hyeoun-Suk Cho, Jun-Hwan Kim, Wan-Gyu Sang, Pyong Shin, Jae-Kyeong Baek, and Myung-Chul Seo

    이윤호, 조현숙, 김준환, 상완규, 신 평, 백재경, 서명철

    Elevated atmospheric carbon dioxide concentration (CO2) is a major component of climate change, and this increase can be expected to continue into ... + READ MORE
    Elevated atmospheric carbon dioxide concentration (CO2) is a major component of climate change, and this increase can be expected to continue into the crop and food security in the future. In this study, Soil-Plant-Atmosphere-Research (SPAR) chambers were used to examine the effect of elevated CO2, temperature, and drought on the canopy architecture and concentration of macronutrients in potatoes (Solanum tuberosum L.). Drought stress treatments were imposed on potato plants 40 days after emergence. Under AT+2.8C700 (30-year average temperature + 2.8℃ at 700 μmol mol-1 of CO2), at maximum leaf area, elevated CO2, and no drought stress, a significant increase was observed in both the aboveground biomass and tuber, and for the developmental stage. Even though CO2 and temperature had increased, AT+2.8C700DS (30-year average temperature + 2.8℃ at 700 μmol mol-1 of CO2 under drought stress) under drought stress showed that the leaf area index (LAI) and dry weight were reduced by drought stress. At maturity, potatoes grown under CO2 enrichment and no drought stress exhibited significantly lower concentrations of N and P in their leaves, and of N, P, and K in tubers under AT+2.8C700. In contrast, elevated CO2 and drought stress tended to increase the tuber Mg concentration under AT+2.8C700DS. Plants grown in AT+2.8C700 had lower protein contents than plants grown under ATC450 (30-year average temperature at 400 μmol mol-1 of CO2). However, plants grown under AT+2.8C700 showed higher tuber bulking than those grown under AT+2.8C700DS. These findings suggest that the increase in CO2 concentrations and drought events in the future are likely to decrease the macronutrients and protein concentrations in potatoes, which are important for the human diet. - COLLAPSE
    June 2018