• Journal of the Korean Society of Food Science and Nutrition
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• 제44권11호
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• pp.1653-1659
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• 2015

This study compared physicochemical properties and antioxidant activities according to different harvest times in five varieties of black rice (BR). Five cultivars of BR, Nunkeunheukchal (NKHC), Sinnongheugchal (SNHC), Sintoheugmi (STHM), Josaengheugchal (JSHC), and Heugjinju (HJJ), were selected for the study. Cultivars were transplanted on June 20th and cultivated by the Department of Southern Area Crop Science, NICS in Miryang, Korea. Heading dates of NKHC, SNHC, STHM, JSHC, and HJJ were Aug. 17th, Aug. 30th, Sep. 1st, Aug. 20th, and Aug. 12th, respectively. The five different harvest times were as follows; 35, 40, 45, 50, and 55 days after heading date. The highest level of anthocyanin was 35 days after heading date in all varieties. Levels of anthocyanin in NKHC, SNHC, STHM, JSHC, and HJJ were 164, 203, 251, 67, and 210 mg/100 g, respectively. Content of anthocyanin significantly decreased 35 days after heading in four varieties, excluding JSHC. Highest DPPH $IC_{50}$ values were 57, 29, 10, and $27{\mu}g/mL$ in NKHC, SN HC, STHM, and JSHC extracts, respectively. Highest ABTS $IC_{50}$ values were 24, 13, 9, and $11{\mu}g/mL$ in NKHC, SNHC, STHM, and JSHC extracts, respectively. The antioxidant activities were highest 35 days after the heading date and significantly decreased in four varieties, excluding HJJ. The antioxidant activity of HJJ showed no significant difference, according to harvest time. This study suggests that the content of anthocyanin and antioxidant activity could be considered as factors affecting optimal harvest period to produce highly qualified black rice.

• Research in Plant Disease
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• 제17권1호
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• pp.19-24
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• 2011

It was identified as a sharp eyespot (Rhizoctonia cerealis) that the isolates from abnormal symptoms in wheat that showed yellowing leaves, necrotic spot on stem base and dead tillers. These isolates have slower growth property and fewer mycelia than Rhizoctonia solani AG-1(1A) (KACC 40106). They showed binuclear cell, same media cultural and DNA characteristics to R. cerealis. They caused same symptoms on leaves and stem base appeared in artificial inoculation test, comparing to diseased wheat fields and also affect to maturing of kernels. They have optimal growth temperature and acidity on the artificial media as $20{\sim}25^{\circ}C$ and pH 5~7, respectively. In the investigation of varietal resistance of Korean winter cereal crops to sharp eyespot, there was no resistant in wheat cultivars that all materials infected over 20% diseased ratio. 12 cultivars including 'Anbaekmil', however, considered to moderate resistance with 20 to 30% infection ratio. The others crops using in feeding, whole crop barley, oat, rye and triticale were resistant below 15% diseased degree except the rye that showed over 50% infection rate. It was the first evaluation to sharp eyespot resistance for the Korean feeding crop cultivars. Most tested Korean barley cultivars for malting and food were moderate and susceptible to the sharp eyespot. Only 3 hulled barley, 'Tapgolbori', 'Albori' and 'Seodunchalbori', showed resistance with less than 10% diseased ratio. All tested naked barley cultivars showed susceptible response to the disease.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제63권3호
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• pp.196-204
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• 2018

The main objective of this study was to identify the best quality rice for cultivation on reclaimed land in Jeollabukdo-Province based on yield, head rice ratio, protein content, amylose content, and Toyo taste value evaluations. Seven varieties of rice were grown for two years on the reclaimed land. The Sukwang variety had the earliest heading date. The tiller number for the Younghojinmi variety was 19 on average, and its variation in tiller number was the lowest, which showed that the safety for cultivation of the variety was high on the reclaimed land with respect to that of the other varieties. The culm and panicle lengths of the Sukwang and Hyunpum varieties were the highest at 81.8 and 21.3 cm, respectively. Shindongjin produced the highest thousand grain weight at 27.7 g, whereas Haepum produced the lowest at 22.3 g. The number of grains per panicle for 7 all varieties was statistically equal for both years. The yield order for the varieties was Shindongjin (590) > Hopum (575) > Younghojinmi (552) > Sukwang (551) > Hopum (543) > Mipum (534) > Haepum (498 kg/10a), which showed that there was no significant difference in average yield between the varieties when both years are taken into consideration. However, the annual difference in Haepum yield between 2015 and 2016 was the highest at 108 kg/10a, indicating low cultivation safety. The head rice ratio of Younghojinmi was higher than for the other cultivars in both 2015 and 2016. However, there was no significant difference between the 2 years when the averages for all varieties were analyzed. There was was a considerable difference in protein and amylose content between the varieties in the two years, although this was not apparent in the results when the average over 2 years for each variety was calculated. There was no significant difference between the two years with respect to the average head rice ratio, and the protein and amylose contents of the seven varieties. The Toyo taste values for the Sukwang and Mipum varieties were higher than for the other varieties. Based on the principle characteristics, such as Toyo value, the Sukwang variety is a suitable substitute for Shindongjin, which has been previously used to produce high-quality rice on the reclaimed land.

• Korean Journal of Weed Science
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• 제9권3호
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• pp.183-200
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• 1989

An experiment was conducted at the greenhouse of the International Rice Research Institute in 1987 to find out the character of dry matter production, the potential seed production ability and the ecological and physiological strategies to adaptation. For these, two rice cultivars, IR64(lowland rice) and UPLRi-5(upland rice), and seven weed species were used ; Echinochloa glabrescens Munro ex Hook. f., E. cress-galls ssp. hispidula (Retz.) Honda, E. colons (L.) Link, Monochoria vaginalis (Burin. f.), Ludwigia octovalvis Jacq.) Raven, Fimbristylis miliacea Vahl and Cyperus difformis L. Adaptation strategies of weed species varied by species. However, they had efficient seed production strategy through different ways. In general, sedge weed species (F. miliacea and C. difformis) produced great amount of seeds at the expense of seed size through greater ratooning ability and low relative dry weight for flowering. For broadleaved weed species, greater number of descendants were obtained through high plasticity and low relative dry weight for flowering (M. vaginalis) or greater growth ability through effective photosynthetic efficiency (L. octovalvis). Grass weed species, on the other hand, produced their seeds through effective growth (net assimilation rate and relative growth rate), high ratooning ability (except E. crus-galls ssp. hispidula) or low relative dry weight to maximum dry weight for flowering (E. glabrescens). The harvest indices of the weed species were considerably lower than those of rice. Fimbristylis miliacea had the greatest ratooning ability followed by C. difformis, E. colons and E. glabrescens. The greatest seed productivity was recorded by C. difformis (279, 000) and L. octovalvis (268,000) while rice produced the least number of seeds (1300-6100). Log seed weight had a negative linear relationship with log seed number (y=6.30-1.48X, $R=-0.965^{**}$). For all species plant plasticity response was not directly correlated with mortality response.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제62권4호
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• pp.317-324
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• 2017

The purpose of this study was to provide basic data on the genetic and environmental effects of stickiness in glutinous rice varieties. In our study, we analyzed the genotype-by-environment ($G{\times}E$) interactions of the stickiness using six glutinous rice varieties under six environmental conditions. AMMI (Additive Main Effects and Multiplicative Interaction) analysis results showed that genotype (variety, G), environment (cultivation region, E) and $G{\times}E$ interaction were highly significant (P < 0.001). Among all the variations of stickiness for glutinous rice varieties, the environmental effect was 24.5%, the genetic effect was 37.1%, and the $G{\times}E$ interaction effect was 28.9%. From the AMMI analysis, the IPCA1 scores of Aranghangchal (G6, IPCA1: 3.85) and Hwaseonchal (G4, IPCA1: -5.24) was lower than other varieties. On the other hand, the Sangjuchal (G1, IPCA1: -61.23) and Boseogchal (G2, IPCA1: 41.21) were highly affected by environmental effects. In this study, there were large differences in stickiness according to region of cultivation. In the future, it is considered that a precise study should be carried out on the environmental factors that may increase the stickiness of glutinous rice varieties.

• Korean Journal of Breeding Science
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• 제49권3호
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• pp.235-244
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• 2017

'Manbaek' is a bacterial blight resistant mid-late maturing rice cultivar with high grain quality. 'Manbeak' was derived from anther culture using the backcross combination, $Hopum^*2/SR30075$. 'Hopum' is a mid-late maturing rice cultivar with high grain quality and 'SR30075' is a pyramid line carrying three bacterial blight resistance genes. 'Manbaek' was selected through the pedigree method, yield trials, and local adaptability tests. 'Manbeak' carrying two bacterial blight resistance gene Xa3 and xa5 showed high-level and broad-spectrum resistance against bacterial blight. 'Manbaek' was resistant to K3a, mostly virulent race in Korea, and exhibited resistance reaction against 16 Korean bacterial blight isolates. 'Manbaek' was a mid-late maturing rice. The heading date of 'Manbaek' was August 19th, which was 5 days later than that of 'Nampyeong'. Manbaek' was a lodging-tolerant rice with short culm and dark green leaf. Due to the low viviparous germination, 'Manbaek' could be a useful material to prevent pre-harvest sprouting. 'Mabeak' was resistant to bacterial blight and rice stripe virus, but susceptible to other virus diseases and insect pests. The yield of 'Manbaek' was similar to 'Nampyeong'. 'Manbaek' showed excellent grain appearance and good tastes of cooked rice, so that it could contribute to improving the quality of bacterial blight resistant cultivars. 'Manbaek', bacterial blight resistant cultivar with high grain quality, is suitable for the cultivation at bacterial blight prone area and has been utilized in the breeding programs for enhancing the resistance against bacterial blight (Registration No. 6069).

• Korean Journal of Agricultural and Forest Meteorology
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• 제20권4호
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• pp.296-304
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• 2018

The objective of this study was to analyze the impact of climate change on rice yield and quality. Experiments were conducted using SPAR(Soil-Plant-Atmosphere-Research) chambers, which was designed to create virtual future climate conditions, in the National Institute of Crop Science, Jeonju, Korea, in 2016. In the future climate conditions($+2.8^{\circ}C$ temp, 580 ppm $CO_2$) of year 2051~2060 according to RCP 8.5 scenario, elevated temperature and $CO_2$ accelerated the heading date by about five days than the present climate conditions, resulted in a high temperature environment during grain filling stage. Rice yield decreased sharply in the future climate conditions due to the high temperature induced poor ripening. And the spikelet numbers, ripening ratio, and 1000-grain weight of brown rice were significantly decreased compared to control. The rice grain quality was also decreased sharply, especially due to the increased immature grains. In the future climate conditions, expression of starch biosynthesis-related genes such as granule-bound starch synthase(GBSSI, GBSSII, SSIIa, SSIIb, SSIIIa), starch branching enzyme(BEIIb) and ADP-glucose pyrophosphorylase(AGPS1, AGPS2, AGPL2) were repressed in developing seeds, whereas starch degradation related genes such as ${\alpha}-amylase$(Amy1C, Amy3D, Amy3E) were induced. These results suggest that the reduction in yield and quality of rice in the future climate conditions is likely caused mainly by the poor grain filling by high temperature. Therefore, it is suggested to develop tolerant cultivars to high temperature during grain filling period and a new cropping system in order to ensure a high quality of rice in the future climate conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제67권1호
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• pp.17-26
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• 2022

Rice is one of the three major grains globally, and has been used as a staple food in Asian countries for a long time. In recent years, with the increase in the use of processed rice, the development and distribution of rice flour varieties have become a research focus. However, rice flour varieties are susceptible to pre-harvest sprouting (PHS). In this study, the optimal transplanting date for rice flour varieties for maximum yield production with PHS avoidance was examined. Four rice flour varieties with different maturity types (early maturing type, Garumi2 and medium-late maturing type, Seolgaeng, Hangaru, and Singil) were selected. The field experiment was conducted in Chuncheon (Central Plain area) and Cheorwon (Northern Plain area), Gangwon Province, Republic of Korea, from 2017 to 2019. The transplanting dates used were May 10, May 20, May 30, June 10, and June 20 in Chuncheon and April 30, May 10, May 20, May 30, and June 10 in Cheorwon. In Chuncheon, late transplantation decreased PHS in Garumi2. In Cheorwon, PHS in Garumi2 decreased with transplantation dates after May 20. The PHS decreased in Seolgaeng, Hangaru, and Singil with late transplantation in Chuncheon and Cheorwon. The optimal transplanting date for maximum yield production while avoiding PHS for Garumi2 was estimated to be June 10 in Chuncheon and May 25 in Cheorwon; for Seolgaeng, the optimal transplanting dates were May 20 in Chuncheon and May 15 in Cheorwon; for Hangaru, it was estimated to be May 30 in Chuncheon and May 15 in Cheorwon; and for Singil, the optimal dates were May 25 in Chuncheon and May 15 in Cheorwon.

• Research in Plant Disease
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• 제29권3호
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• pp.243-250
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• 2023

To explore the distribution and the resistance reaction of rice blast pathogens that may occur in North Korea, rice blast pathogens in the North Korean border regions of Dandong and Yeon-gil in China and the North Korean border region of Cheorwon in South Korea were analyzed. In addition, comparative analysis was conducted with rice blast pathogen in Suwon and Jeonju, inland regions of South Korea. Resistance reactions above average were observed in monogenic rice lines (IRBLzt-T, IRBL9-W, IRBL20-IR24, and IRBLta-CP1) in Jeonju, Suwon, and Cheorwon from 2018 to 2020. In Dandong and Yeon-gil, the monogenic lines IRBLz5-CA, IRBL12-M, and IRBL19-A consistently showed resistance reactions for three years. Notably, IRBL19-A exhibited strong resistance. Race distribution analysis in South Korea indicated a shift from KI to KJ dominance from 2018 to 2020, while in the North Korean border regions of Dandong and Yeon-gil, the KI race was dominant in 2021 and 2022. The race distribution of rice blast pathogens in China's North Korean border regions differed significantly from that in South Korea.

• Journal of Plant Biotechnology
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• 제47권2호
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• pp.124-130
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• 2020

The sweet potato (Ipomoea batatas [L.] Lam.) is the sixth-most important crop in the world following rice, wheat, potato, maize, and cassava. Four varieties ('Beniharuka', 'Annobeni', 'Pungwonmi', 'Hogammi') and their Japanese cultivars are broadly distributed in South Korea. In the Korean marketplace, sweet potatoes are classified by color and shape, not by variety, making it necessary to differentiate varieties for uniform production and consumption. In this study, molecular markers were developed to distinguish the four varieties of sweet potato using SNPs and genotyping-by-sequencing (GBS) analysis via a tetra-primer amplification refractory mutation system (ARMS)-PCR. The results revealed that three variety-specific fragments (164 bp and 241 bp of SNP 04-27457768 and 292 bp of SNP 03-16195623) were amplified in the 'Beniharuka', 'Pungwonmi', and 'Annobeni' sweet potato varieties. There were instances where some varieties produced three bands within the gel electrophoresis, indicating heterozygosity at the given SNPs loci. DNA sequencing analysis also confirmed the results of electrophoresis at the SNPs loci. Overall, these molecular markers would provide a useful, rapid, and, simple evaluation method for the Korean sweet potato marketplace, where the mixing of varieties is a serious issue.