• Research Article

    Utilization of Elite Korean Japonica Rice Varieties for Association Mapping of Heading Time, Culm Length, and Amylose and Protein Content
    Youngjun Mo, Jong-Min Jeong, Bo-Kyeong Kim, Soon-Wook Kwon, and Ji-Ung Jeung
    Association mapping is widely used in rice and other crops to identify genes underlying important agronomic traits. Most association mapping studies use ... + READ MORE
    Association mapping is widely used in rice and other crops to identify genes underlying important agronomic traits. Most association mapping studies use diversity panels comprising accessions with various geographical origins to exploit their wide genetic variation. While locally adapted breeding lines are rarely used in association mapping owing to limited genetic diversity, genes/alleles identified from elite germplasm are practically valuable as they can be directly utilized in breeding programs. In this study, we analyzed genetic diversity of 179 rice varieties (161 japonica and 18 Tongil-type) released in Korea from 1970 to 2006 using 192 microsatellite markers evenly distributed across the genome. The 161 japonica rice varieties were genetically very close to each other with limited diversity as they were developed mainly through elite-by-elite crosses to meet the specific local demands for high quality japonica rice in Korea. Despite the narrow genetic background, abundant phenotypic variation was observed in heading time, culm length, and amylose and protein content in the 161 japonica rice varieties. Using these varieties in association mapping, we identified six, seven, ten, and four loci significantly associated with heading time, culm length, and amylose and protein content, respectively. The sums of allelic effects of these loci showed highly significant positive correlation with the observed phenotypic values for each trait, indicating that the allelic variation at these loci can be useful when designing cross combinations and predicting progeny performance in local breeding programs. - COLLAPSE
    March 2020
  • Research Article

    Impact of Heat Stress on Pollen Fertility Rate at the Flowering Stage in Korean Rice (Oryza sativa L.) Cultivars
    Tran Loc Thuy, Chung-Kuen Lee, Jae-Hyeok Jeong, Hyeon-Suk Lee, Seo-Young Yang, Yeon-Hwa Im, and Woon-Ha Hwang
    Rice is very sensitive to high temperatures during the reproductive stage, particularly during the flowering and anthesis periods. To determine how high ... + READ MORE
    Rice is very sensitive to high temperatures during the reproductive stage, particularly during the flowering and anthesis periods. To determine how high temperatures result in sterility during the flowering period in Korean rice cultivars, groups of 11 cultivars were subjected to different temperature regimes (24, 28, 30, and 33°C) during the flowering stage using sunlit phytotrons. At an average of 33°C, all 11 rice cultivars reached anthesis earlier than at the other temperatures. Microscopy analyses revealed significant differences in pollen germination and pollen viability in cultivars grown at 33°C compared to those cultured at lower temperatures. At 33°C, the cultivars had significantly lower fertility rates (47% reduction) than cultivars grown at 24°C. These findings are important as rice pollination and fertility depend on the pollen viability and germination. The present study shows that rice fertility is negatively affected by excessively high temperatures. - COLLAPSE
    March 2020
  • Research Article

    Methods of Application and Beneficial Effects of Silicate-Coating Rice Seeds

    볍씨의 규산코팅방법에 따른 이용특성과 육묘효과

    Yang-Soon Kang, Wan Joong Kim, Duck Sang Hwang, and Hee Kyu Kim

    강양순 ・ 김완중 ・ 황덕상 ・ 김희규

    A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed ... + READ MORE
    A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings. - COLLAPSE
    March 2020
  • Research Article

    Quality Characteristics of Fish Cakes Containing Flour Derived from Eight Rice Varieties

    벼 품종 특성에 따른 쌀어묵의 품질 특성

    Hyun-Joo Kim, Yu-Young Lee, Byong Won Lee, Koan Sik Woo, Jun Hyeon Cho, Jihae Lee, and Byoungkyu Lee

    김현주 ・ 이유영 ・ 이병원 ・ 우관식 ・ 조준현 ・ 이지혜 ・ 이병규

    In this study, we examined the quality of fish cakes prepared using the flour obtained from the following different rice varieties: Baekogchal ... + READ MORE
    In this study, we examined the quality of fish cakes prepared using the flour obtained from the following different rice varieties: Baekogchal, Dodamssal, Hangaru, Jeogjinju 2, Josaengheugchal, Saeminyeon, Saeilmi, and Shingil. The moisture content of the fish paste containing rice flour ranged from 67.40% to 69.90%, and was highest in the paste prepared using Baekogchal flour. The lipid and protein contents of the paste ranged from 0.05% to 0.43% and 11.36% to 11.69%, respectively, whereas the carbohydrate content was between 10.36% and 12.32%, and was highest in the paste prepared using Jeogjinju 2 flour. Fish cakes prepared using the flour from Baekogchal, Jeogjinju 2, and Josaengheugchal rice were found to have the hardest consistency. Sensory evaluations indicated that fish cakes prepared using Shingil flour had the best texture. Furthermore, the total polyphenol content was significantly higher in the fish cakes prepared using Josaengheugchal flour (165.12 mg GAE/100 g), whereas the DPPH and ABTS radical scavenging activities were significantly higher in the fish cakes prepared using Josaengheugchal flour (39.37 and 175.37 mg TE/100 g, respectively). In conclusion, we confirmed that the quality of fish cakes is affected by the characteristics of the flours obtained from different rice varieties. Among the varieties assessed, the quality of Shingil and Josaengheugchal varieties was suitable for preparing rice-containing fish cakes. - COLLAPSE
    March 2020
  • Research Article

    Classification of Flowering Group and the Evaluation of Flowering Characteristics for Soybean (Glycine max Merrill) Varieties from North Korea

    북한 콩 품종의 개화기 군 분류와 개화특성 평가

    Hye Ji Lee, Bo Hwan Kim, Wook Kim, and Sei Joon Park

    이혜지 ・ 김보환 ・ 김욱 ・ 박세준

    This study was conducted to evaluate the flowering characteristics of 22 soybean (Glycine max Merrill) varieties of North Korea and classify the ... + READ MORE
    This study was conducted to evaluate the flowering characteristics of 22 soybean (Glycine max Merrill) varieties of North Korea and classify the flowering group by the flowering date. The flowering date and the days required for flowering with the different planting times on May 31, June 19, June 30, July 3, and July 4 were investigated at the agricultural experimental field of Korea University for three years from 2017 to 2019. The flowering date and the days for flowering of “Yeonpungkong”, an early maturing soybean cultivar of Korea, were July 18 and 48 days, respectively, at the planting time of May 31, those of “Daewonkong”, a mid-late maturing cultivar, were July 30 and 60 days, respectively. Based on the flowering dates of “Yeonpungkong” and “Daewonkong”, North Korean soybean varieties were classified into six flowering groups. Eight North Korean soybean varieties had the flowering dates earlier than “Yeonpungkong”, including “Brekkhat” classified into the early flowering group. The range of flowering date was July 2 to 15 at planting time of May 31. Twelve North Korean soybean varieties had flowering dates similar to or later than “Daewonkong”, including “Chang Dan Bac Mok” classified into the mid-late flowering group. The range of flowering date was July 24 to 30 at the planting time of May 31. For flowering response to environmental stimulus, all of the mid-late flowering varieties of North Korea responded to “photosensitive or day-length” for flowering reaction. The early flowering varieties were divided by “photosensitive” response and “temperature” response variety. - COLLAPSE
    March 2020
  • Research Article

    Estimation of Meteorological Ecology of Soybean (Glycine max Merrill) for Crop Cultivation Regions of North Korea

    북한 지역의 콩 기상 생태형 설정 연구

    Bo Hwan Kim, Hye Ji Lee, Wook Kim, and Sei Joon Park

    김보환 ・ 이혜지 ・ 김욱 ・ 박세준

    The meteorological ecology of a soybean variety (Glycine max Merrill) and its characteristics are important factors in selecting soybean variety suitable for ... + READ MORE
    The meteorological ecology of a soybean variety (Glycine max Merrill) and its characteristics are important factors in selecting soybean variety suitable for the environment. This experiment was conducted to estimate the meteorological-ecological characteristics of soybean for 27 crop cultivation regions in North Korea. The meteorological ecology of each region was determined by the last harvest date and the maximum growth day determined using the daily minimum temperature of the region. The soybean meteorological group for 27 regions in North Korea was classified by eight groups. The last harvest date of group I, the south-west and south-east areas, was from October 21 to 29, which was the latest harvest date among the eight groups. It became shorter toward the central inland and mountainous areas of group IV, and it ranged from September 18 to October 2. The maximum number of growth days was 153~160 days in group I, and 100~111 days in group IV-3, the northernmost area of ​​the east coast. Assuming total growth days as 110 days, the ranges of last flowering dates (and the day length) of group I, II, III, and IV were August 12~19 (day length of 13.5~13.8 h), August 2~6 (14-14.2 h), July 27~August 2 (14.2~14.4 h), and July 10~22 (14.5~14.8 h), respectively. The accumulative temperature of 110 growth days was above 2,400°C in group II-1, the south to north area of the west inland, and above 2,300°C in all regions except Cheongjin, Seonbong, and Jung-gang. The accumulative temperature calculated based on the maximum growth day was above 3,000°C in group I and II-1 and above 2,500°C in group II-2, the central area of the east coast, III-1, the central inland area, and IV-1, the central inland mountain area. - COLLAPSE
    March 2020
  • Research Article

    Seeding Soils and Tray Types Mediate Growth Characteristics of Perilla Seedlings

    상토 및 트레이 종류에 따른 종실용 들깨의 육묘 특성

    Jin-Ki Park, Won-Young Han, Kil-Su Han, Jong-Soo Ryu, Ok-Jae Won, Tae-Uk Jeong, Young-Ho Yoon, and Jin-Woo Bae ···

    박진기 ・ 한원영 ・ 한길수 ・ 류종수 ・ 원옥재 ・ 정태욱 ・ 윤영호 ・ 배진우

    The purpose of this study was to analyze the growth characteristics of perilla according to the materials of the seedbed for the ... + READ MORE
    The purpose of this study was to analyze the growth characteristics of perilla according to the materials of the seedbed for the development of seedling plug technology suitable for the mechanical transplantation of perilla. Perilla (Perilla frutescens var. japonica Hara) cultivars Deulsaem and Sodam were used in this experiment. The composition ratios of 170 products from 16 companies published in the ‘Korean Association of Seedbed Media’ homepage were compared according to usage and type, and 11 products that corresponded to the average were selected. The seedbed was classified according to the seedbed for paddy rice as light-weight, semi-weight, and weight, and based on the seedbed for horticulture, as light-weight and ultra-light. The seedlings were placed in 72-cell (semi-automatic), 128-cell (automatic) and 220-cell (automatic) plug trays. We selected 2 light-weight seedbeds of paddy rice and 2 light-weight seedbeds of horticultural products with the highest plant growth. We analyzed plant height and mat formation of the perilla roots. Results showed that the perilla height and mat formation were the best in light-weight seedbeds of paddy rice (product R1). Therefore, light-weight seedbeds of rice (product R1) were suitable for perilla plant transplantation. The estimated major components were vermiculite 41.0%, cocopeat 31.0%, peat moss 5.7%, and red-yellow soil 20.0%. The mechanical transplantation of perilla significantly boosts plant growth and reduces sowing and thinning efforts. However, continuous evaluation of newly introduced, commercial seedbeds is needed. - COLLAPSE
    March 2020
  • Research Article

    Effect of Miscanthus Biomass Application on Upland Soil Physicochemical Properties and Crops Growth

    억새 바이오매스 시용이 밭토양 이화학성과 작물 생육에 미치는 영향

    Yong Ku Kang, Youn Ho Moon, Da Eun Kwon, Ji Eun Lee, Kwang Soo Kim, and Young Lok Cha

    강용구 ・ 문윤호 ・ 권다은 ・ 이지은 ・ 김광수 ・ 차영록

    In this study, miscanthus with C/N ratio of 224 were applied to the soil and treated with 0 (control), 10 tons ... + READ MORE
    In this study, miscanthus with C/N ratio of 224 were applied to the soil and treated with 0 (control), 10 tons and 20 tons·ha-1 to improve the soil and promote crop growth. As a result, soil organic matter content increased from 11.0 g·kg-1 before the test to 16.3 after 3 years. Soil cation exchangeable capacity increased to 15.3 cmolc·kg-1 after 3 years. In the sweet sorghum, stem was the most thickest at 20 tons·ha-1 application of miscanthus and the highest juice amount per plant was 60 ml. The yield index multiplied by the soluble solids content of juice and juice amount was the highest at 1,913 for 10 tons application and 1,851, 1,839 for 20 tons, control respectively. Number of sweetpotato storage root were 2,9 in 20-tons application plot, the same as control, and 10-tons application plot was 3.6, the most. Two-year average yields of 20 tons plot and control were low at 2,579 kg/10a and 2,708 respectively, and 10 tons plot was the highest at 3,289. For onions, the biomass application did not effect the yield. but onion plant and leaf length were longer in 20 tons plot than in control or 10 tons. The yield of garlic was 2,630~2,901 kg/10a and there was no effect of miscanthus application. Plot of 10 tons application were the longest in plant and leaf length, and the number of scale was 8.2-8.3 per in bulb, and 8.9 tons·ha-1 in control. Therefore, it was confirmed the possibility that miscanthus biomass application of about 10 tons·ha-1 could improve the soil condition and promote crops growth and yield. - COLLAPSE
    March 2020