• Research Article

    Improvement of Seedling Establishment in Wet Direct Seeding of Rice using the Anaerobic Germination Tolerance Gene Derived from Weedy Photoblastic Rice

    잡초벼 PBR 혐기발아 내성 유전자 활용 벼 담수직파 초기 입모 개선

    Jong-Min Jeong, Youngjun Mo, Man-Kee Baek, Woo-Jae Kim, Young-Chan Cho, Su-Kyung Ha, Jinhee Kim, Ji-Ung Jeung, and Suk-Man Kim

    정종민 ・ 모영준 ・ 백만기 ・ 김우재 ・ 조영찬 ・ 하수경 ・ 김진희 ・ 정지웅 ・ 김석만

    Direct seeding is one of the rice seedling establishment methods that is increasingly being practiced by farmers to save labor and reduce ... + READ MORE
    Direct seeding is one of the rice seedling establishment methods that is increasingly being practiced by farmers to save labor and reduce costs. However, this method often causes poor germination under flooding conditions after sowing. In this study, we developed japonica elite lines with quantitative trait loci (QTL) associated with anaerobic germination (AG) tolerance to overcome poor germination and seedling establishment in wet direct seeding. The QTL introgression lines were developed from a cross between weedy photoblastic rice as the AG donor and the Nampyeong variety via phenotypic and genotypic selection. Compared to Nampyeong, the survival rates of the selected lines were improved by approximately 50% and 240% under field and greenhouse conditions, respectively. To improve selection efficiency by marker assisted selection, the QTL markers associated with AG tolerance were converted to cleaved amplified polymorphic sequence markers designed based on next-generation sequence analysis. These lines retained similar agronomic traits and yield potential to the parent, Nampyeong. Among these lines, we selected the most promising line, which exhibited high survival rate and good agricultural traits under flooding conditions and named the line as Jeonju643. This line will contribute to breeding programs aiming to develop rice cultivars adapted to wet direct seeding. This study demonstrates the successful application of marker-assisted selection to targeted introgression of anaerobic genes into a premium quality japonica rice variety. - COLLAPSE
    September 2020
  • Research Article

    Genetic and Agronomic Analysis of a Recombinant Inbred Line Population to Map Quantitative Trait Loci for Blast Resistance and Select Promising Lines in Rice

    벼 RIL집단의 유전 분석과 농업형질 분석을 통한 도열병 저항성 QTL 탐색 및 유망계통 선발

    Su-Kyung Ha, Ji-Ung Jeung, Jong-Min Jeong, Jinhee Kim, and Youngjun Mo

    하수경 ・ 정지웅 ・ 정종민 ・ 김진희 ・ 모영준

    Koshihikari has been one of the most popular rice cultivars with good eating quality since the 1960s despite its susceptibility to blast ... + READ MORE
    Koshihikari has been one of the most popular rice cultivars with good eating quality since the 1960s despite its susceptibility to blast disease and lodging. To map the genes controlling blast resistance and to develop promising blast-resistant breeding lines inheriting Koshihikari’s high eating quality, a recombinant inbred line (RIL) population was developed from a cross between Koshihikari and a blast resistance donor with early maturity, Baegilmi. A total of 394 Koshihikari × Baegilmi RILs (KBRIL), and the two parents, were evaluated for blast resistance and major agronomic traits including heading date, culm length, panicle length, and tiller number. A linkage map encompassing 1,272.7 cM was constructed from a subset of the KBRIL (n = 142) using 130 single nucleotide polymorphisms. Two quantitative trait loci (QTL) for blast resistance, qBL1.1 harboring Pish/Pi35 and qBL2.1 harboring Pib, were mapped onto chromosomes 1 and 2, respectively. qBL1.1 was detected in both of the experimental sites, Namwon and Jeonju, while qBL2.1 was only detected in Namwon. qBL1.1 and qBL2.1 did not affect agronomic traits, including heading date, culm length, panicle length, and tiller number. From the 394 KBRILs, lines that were phenotypically similar to Koshihikari were selected according to heading date and culm length and were further divided into the following two groups based on blast resistance: Koshishikari-type blast resistant lines (KR, n = 15) and Koshishikari-type blast susceptible lines (KS, n = 15). Although no significant differences were observed in the major agronomic traits between the two groups, the KR group produced a greater mean head rice ratio than the KS group. The present study provides useful materials for developing blast-resistant cultivars that inherit both Koshihikari’s high eating quality and Baegilmi’s blast resistance. - COLLAPSE
    September 2020
  • Research Article

    Optimum Grain Filling Temperature for Yield Improvement of Rice Varieties Originated from High-Altitude Areas

    고위도 지역 재배 벼 품종의 수량 향상을 위한 등숙적온 분석

    Woonho Yang, Shingu Kang, Jong-Seo Choi, Jeong-Hwa Park, and Sukjin Kim

    양운호 ・ 강신구 ・ 최종서 ・ 박정화 ・ 김숙진

    A field test and a phytotron study were performed over two years to examine whether rice varieties originated from higher altitude areas ... + READ MORE
    A field test and a phytotron study were performed over two years to examine whether rice varieties originated from higher altitude areas have lower optimum grain filling temperatures for yield improvement than the varieties from South Korea. Three varieties originated from North Korea and three varieties from northern China were compared to the same number of varieties from South Korea. In a field study, the optimum grain filling temperatures over 40 days after heading were 22.6 – 23.0°C, 21.5 – 22.3°C, and 21.5 – 23.6°C for the varieties from North Korea, northern China, and South Korea, respectively, resulting in no significant difference among varietal groups. Meanwhile, the heading dates of the early maturing varieties from North Korea and China were 7 - 12 days earlier than that of the early maturing Odae variety from South Korea during the first transplant of 2017. The phytotron study, in which different temperature regimes were imposed from flowering/fertilization to harvest with constant daily mean temperatures, revealed that milled rice weight did not decrease under low temperatures, even at 16°C, compared to that at 22°C. At the fourth transplant in the field study, mean temperature lower than 10°C appeared before rice grains were fully developed, resulting in yield reductions. It was concluded that rice varieties adaptable to high-altitude areas do not have lower optimum grain filling temperatures but, instead, possess shorter growth durations. It was further suggested that the optimum grain filling temperature of rice observed under natural conditions could be attributed to the lowering temperature at the late filling stage under temperate climatic conditions. - COLLAPSE
    September 2020
  • Research Article

    Changes in the Growth of Young Rice Seedlings in the Root Extension Stage under Different Growth Conditions

    벼 착근기 생육 환경에 따른 어린모의 생육변화 분석

    Myoung Goo Choi, Jae-Hyeok Jeong, Hyen-Seok Lee, Seo-Yeong Yang, Chung-gun Lee, and Woon-Ha Hwang

    최명구 ・ 정재혁 ・ 이현석 ・ 양서영 ・ 이충근 ・ 황운하

    Root extension is the most important growth change that occurs during cultivation. We analyzed growth changes according to young seedling age, temperature ... + READ MORE
    Root extension is the most important growth change that occurs during cultivation. We analyzed growth changes according to young seedling age, temperature, and the degree of root cutting in order to identify factors affecting rooting after transplanting. Root cutting did not affect plant height growth rate, root growth rate was increased in plants that experienced root cutting, and 14-day-old seedlings exhibited a higher growth rate than 7-day-old seedlings. Growth temperature experiments revealed that elongation was high at 25°C and 28°C, but tended to be low at 18°C, and root elongation was high at 22–28°C for 7-day-old seedlings and 22–25°C for 14-day-old seedlings. Nitrogen absorption decreased in the following growth temperature order: 25, 28, 22, 18°C, and differences in nitrogen absorption under different growth temperatures tended to be lower in 7-day-old seedlings. The amount of nitrogen taken up by roots did not differ significantly between the short root treatment and the control, and 7-day-old seedlings tended to start nitrogen absorption faster than 14-day-old seedlings. Root vitality was highest in short-rooted 7-day-old seedlings with 3 cm of root remaining, and vitality also tended to be high in short-rooted 14-day-old seedlings. - COLLAPSE
    September 2020
  • Research Article

    Characterization of Traits Related to Grain Shape in Korean Rice Varieties

    국내 육성 벼 품종 입형 관련 특성 분석

    Chang-Min Lee, Keon-Mi Lee, Man-Kee Baek, Woo-Jae Kim, Jung-Pil Suh, Oh-Young Jeong, Young-Chan Cho, Hyun-Su Park, and Suk-Man Kim

    이창민 ・ 이건미 ・ 백만기 ・ 김우재 ・ 서정필 ・ 정오영 ・ 조영찬 ・ 박현수 ・ 김석만

    Grain size and shape are the two important components contributing to rice yield and quality. To analyze traits related to grain-shape, a ... + READ MORE
    Grain size and shape are the two important components contributing to rice yield and quality. To analyze traits related to grain-shape, a total of 272 varieties derived from japonica, japonica black and Tongil-type rice accession in Korea were evaluated in this study. The traits, grain length (GL), grain width (GW), grain thickness (GT), length to width ratio (RLW), and 1000-grain weight (TGW) were measured and replicated 10 times. Genes (GW2, GS3, qGL3, qSW5, GS5, TGW6, GW7, and GW8) related to grain-shape were validated in the accessions using specific DNA marker sets. K-mean clustering of the accession based on phenotypic data revealed three groups: group 1 was classified by GW and GT and included most of japonica type, group 2 was classified by RLW and GL reached a medium size and possessed a half spindle-shaped type, and group 3 was classified by TGW, reached a long size and possessed a semi-round shape. In validation tests using the marker sets, both gw2 and tgw6 were validated in less than 1% of the tested accessions and two allelic types, qgl3 and gw8, were only verified in Tongil-type accessions. For GW8 and GW2, any different amplicons were not amplified in any japonica or Tongil-type accessions, respectively. In order to suggest the representative grain-shape gene combinations for each ecotype, the allelic combinations were evaluated by PCR analysis. Cj1 and 2 in japonica (Cj1-7), Cj_b1 and 2 in japonica-black (Cj_b1-3), and CT3 in Tongil-type (CT1-13) turned out to be the dominant combination in each ecotype, respectively. In addition, the results revealed that introgression of four genes (gw2, gs3, qSW5, and GS5) would expand the diversity of grain shape in Korean japonica varieties. The gene combinations information could be utilized practically to understand or enhance grain shape in japonica rice breeding program. - COLLAPSE
    September 2020
  • Research Article

    Selection of Salt-Tolerant Silage Rice Through in vitro Screening and Saltol QTL Analysis

    기내 선발과 Saltol QTL 분석을 통한 내염성 증진 사료용 벼 선발

    Chuloh Cho, Kyung Hwa Kim, Eok-Keun Ahn, Hyangmi Park, Man-Soo Choi, Jaebuhm Chun, Mi-Suk Seo, Mina Jin, and Dool-Yi Kim

    조철오 ・ 김경화 ・ 안억근 ・ 박향미 ・ 최만수 ・ 전재범 ・ 서미숙 ・ 진민아 ・ 김둘이

    Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary ... + READ MORE
    Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary to develop crops with increased salt tolerance for cultivation in saline soils such as is found in reclaimed land. The objective of this study was to develop a salt-tolerant silage rice line that grows on reclaimed land. In order to develop this salt-tolerant silage rice, we transferred Saltol, a major QTL associated with salt tolerance, from IR64-Saltol, a salt-tolerant indica variety, into Mogyang, a susceptible elite japonica variety. To determine the effect of salt stress, Mogyang and IR64-Saltol cultivars were grown on a medium containing various concentrations of NaCl in in vitro conditions. Shoot length was found to decrease with increasing salt concentrations, and root growth was almost arrested at NaCl concentrations over 50 mM in the Mogyang cultivar. Based on these preliminary results, we screened five salt-tolerant lines showing superior growth under salt stress conditions. Polymerase chain reaction and sequencing results showed that the introgression types of Saltol QTL were derived from the IR64-Saltol cultivar in almost all selected lines. Based on the observed growth and physiological characteristics, the new Saltol introgression lines showed higher salt tolerance compared to the Mogyang parental cultivar. The salt-tolerant lines identified in this study could be used as a genetic resource to improve rice salt tolerance. - COLLAPSE
    September 2020
  • Research Article

    Growth Characteristics and Variation in Amino Acids Composition of Quality Protein Maize Lines

    고라이신(QPM) 주요 계통과 교잡계의 생육특성 및 아미노산 조성 변이

    Hwan-Hee Bae, Beom-Young Son, Young-Sam Go, Hye-Young Park, Gibum Yi, Jun Young Ha, Mi-Jung Kim, Sun-Lim Kim, and Seong-Bum Baek

    배환희 ・ 손범영 ・ 고영삼 ・ 박혜영 ・ 이기범 ・ 하준영 ・ 김미정 ・ 김선림 ・ 백성범

    Maize grain quality can be improved by raising lysine content, which is an essential amino acid present in insufficient quantities in normal ... + READ MORE
    Maize grain quality can be improved by raising lysine content, which is an essential amino acid present in insufficient quantities in normal maize. Maize varieties with such modifications are known as quality protein maize (QPM). To date, no Korean maize cultivars contain high amounts of lysine. To introduce quality protein maize to Korean cultivars, we crossed QPM CIMMYT maize lines (CML) with KS140, an elite inbred line used as a parent of several cultivars such as ‘Gangdaok’ and ‘Pyeonganok’. We analyzed the phenotypic characteristics of F1 plants as well as the protein contents, amino acids, and fatty acids profiles of the self-pollinated seeds of the F1 hybrids, and evaluated the feasibility of CML as a source of QPM. Days to anthesis of the CML ranged from 78 to 90 days after planting (DAP), whereas a range of 81~87 was recorded for F1 hybrids. The average days to anthesis was 85 for KS140, CML, and the F1 hybrids. The protein content of the CML was measured to be between 9.1 and 12.1%, with the highest and lowest values being recorded in CML153 and 191, respectively. The F1 hybrids had protein contents of 9.1~11.1%, and the highest content was observed in KS141/CML188. The fatty acids profiles were very similar across all analyzed maize samples, and linoleic acid (C18:2) composed the greatest proportion. Glutamic acid made up the largest proportion of amino acids in all maize samples. Lysine composition was highest in CML155 (6.92% of all amino acids), with an average composition of 4.83% across the CML. In contrast, KS140 showed a lysine content of 2.51%. In F1 hybrids, the average lysine composition was 3.46%, and KS140/CML164 (4.18%) and KS140/CML163 (4.99%) contained more lysine than either parent. Taken together, these results indicate that CML could become promising QPM sources to improve grain quality in Korean maize cultivars. - COLLAPSE
    September 2020
  • Research Article

    Variation in Physicochemical Characteristics and Antioxidant Activities of Small Redbean Cultivars

    팥 품종의 이화학적 특성 및 항산화 활성 변이

    Jung Sook Sung, Seok Bo Song, Ji Young Kim, Yeon Ju An, Jae Eun Park, Myeong Eun Choe, Ji Ho Chu, Tae Joung Ha, and Sang Ik Han

    성정숙 ・ 송석보 ・ 김지영 ・ 안연주 ・ 박재은 ・ 최명은 ・ 추지호 ・ 하태정 ・ 한상익

    This research was conducted to evaluate the physicochemical properties, antioxidant components, and their activities for more taking advantage of small redbean cultivars ... + READ MORE
    This research was conducted to evaluate the physicochemical properties, antioxidant components, and their activities for more taking advantage of small redbean cultivars. Seed size, 100 seeds weight, and hardness on the 8 cultivars were measured. The free sugar and crude protein contents were evaluated using HPLC and protein analyzer, respectively. Amylose content, antioxidant components, and activities were analyzed by spectrophotometer. The range of 100 seeds weight and hardness were 12.55-18.81 g and 9,527.38-14,341.25 gf, respectively. Total free sugar, amylose, and crude protein were showed 22.49-31.07 mg/g, 13.53-15.67%, and 21.27-23.30%, respectively. The cultivar ‘Hongeon’ was higher antioxidant component and activity more than others. In clustering the cultivars based on the results, the tree showed four major clades. The ‘Huinnarae’ group was high in total free sugar and amylose content. The ‘Hongeon’ group were high in 100 seeds weight, antioxidant component. and activity, while amylose content was lower than that in the other groups. The results of the cultivars can be utilized for research of functional materials. The findings of this study will provide valuable information for expansion of functional food industry related on small redbean. - COLLAPSE
    September 2020
  • Research Article

    Effect of Temperature and Daylength on Flowering and Growth Characteristics

    온도와 일장조건에 따른 참깨 개화 및 생육특성 영향

    Kang Bo Shim, Bon Il Goo, Myoung Na Shin, and Won Tae Jeon

    심강보 ・ 구본일 ・ 신명나 ・ 전원태

    Sesame is typically a temperature- and day length-sensitive plant, as its flowering is promoted under high temperature and shorter day length conditions ... + READ MORE
    Sesame is typically a temperature- and day length-sensitive plant, as its flowering is promoted under high temperature and shorter day length conditions. The experiment carried out in the present study revealed that day length influenced sesame flowering to a much greater extent than temperature. The degree of day length influence differed depending on the sesame variety. Days from sowing to flowering was negatively correlated with yield-related characteristics such as stem length, capsule number per plant, 1,000 seed weight, and seed weight per 10a. In cases where the period from sowing to flowering was longer and flowering date was later, the reproductive growth period was shorter during maturity. Analysis of the effects of temperature and day length on seed yield production revealed that temperature was a much more influential factor than day length. However, day length was more influential than temperature under low temperatures, such as 22°C. All varieties apart from Ansan were shown to be primarily influenced by temperature. Sesame varieties were grouped in view of optimal seed sowing time through principal components analysis. The Poongsung and Sungboon varieties favored early sowing under low temperatures and short day lengths. The DT45, Poongsung, 90 days, Ansan, and Sungboon varieties favored late sowing under high temperatures and long day lengths. The Yangbaek and Arum varieties could be sown both early and late. - COLLAPSE
    September 2020
  • Research Article

    Effect of Harvest Time on Yield Components and Quality in ‘Heuksaeng’, the Purple-Skin Peanut Variety
    Eunyoung Oh, Suk-Bok Pae, Jae Eun Park, Jung-In Kim, Sungup Kim, Myoung-Hee Lee, and Tae Joung Ha
    This study was conducted to investigate the impact of harvest time on yield and seed quality in purple seed coat peanut. Compared ... + READ MORE
    This study was conducted to investigate the impact of harvest time on yield and seed quality in purple seed coat peanut. Compared to the average Virginia peanut variety, ‘Heuksaeng’, purple peanut variety has been reported to experience yield loss and reduced seed quality under delayed harvest. We examined the yield components and seed quality at different harvest times from 70 to 110 days after flowering (DAF), with harvesting occurring at intervals of 10 days. The number of mature pods per plant reached a maximum of 51.0 at 80 DAF, and average pod and seed yield peaked at 80 DAF with values of 5,229 and 3,532 kg per ha, respectively. Seed quality drastically decreased after 100 DAF, and the concentrations of two major anthocyanin compounds were significantly lower under delayed harvest. The antioxidative activities of DPPH and ABTS decreased to only 69 and 83% of their maximum values at 110 DAF. On the basis of these results, we recommend that ‘Heuksaeng’ is harvested approximately 10 to 15 days earlier that average Virginia-type cultivars to obtain the highest yield while minimizing the deterioration of seed quality. - COLLAPSE
    September 2020