• Evaluation of Five Forage Rice Cultivars for Salinity Tolerance at the Seedling Stage and Cultural Practice in a Double-cropping Reclaimed Paddy

    사료벼 5 품종의 발아와 유묘 내염성 및 간척지 이모작 논에서의 생육 평가

    Pil-Mo Sung, Sun-Woong Yun, Eun-Ji Song, Su-Hwan Lee, Jin-Woong Cho, and Nam-Jin Chung

    성필모 ・ 윤선웅 ・ 송은지 ・ 이수환 ・ 조진웅 ・ 정남진

    In this study, we evaluated the salinity tolerance of five forage rice cultivars (Mogwoo, Mogyang, Miwoo, Jowoo, and Yeongwoo) with respect to ... + READ MORE
    In this study, we evaluated the salinity tolerance of five forage rice cultivars (Mogwoo, Mogyang, Miwoo, Jowoo, and Yeongwoo) with respect to germination, seedling growth, productivity, and feed values in a reclaimed paddy field in Muan, Korea. We found that the cultivars Mogwoo, Miwoo, Jowoo, and Yeongwoo showed normal germination and seedling growth, even at saline concentrations of between 0.1% and 0.5%, whereas in contrast, there were significant reductions in the germination and seedling growth of Mokyang with an increase in salt concentration. Among the five cultivars assessed, the seedling growth of Mogwoo and Yeongwoo was relatively higher at different salt concentrations in hydroponic and sand cultivation. Furthermore, cultivation of the five cultivars in the reclaimed paddy field with an initial salt concentration of 0.3% revealed that Yeongwoo was relatively superior in terms of yield and feed value. In conclusion, the germination and early growth of Yeongwoo were relatively good at high salt concentrations, and the yield and forage value of this cultivar in a reclaimed paddy field were also relatively superior to those of the other assessed varieties. - COLLAPSE
    December 2020
  • Effect of Climate on the Yield of ‘Ilpum’ Rice Cultivar in Gyeongbuk Province, South Korea over the Past 25 Years

    경북 내륙 지역 과거 25년간 기후와 일품벼 수량 변화

    Shin, Jong-Hee1*, Han, Chae-Min1, Kwon, Jung-Bae2, Kim, Jong-Su2 and Kim, Sang-Kuk3
    ‘Ilpum’, a Korean short-grain mid-late maturing rice cultivar, was developed in 1990, more than 30 years ago. Despite its age, it has ... + READ MORE
    ‘Ilpum’, a Korean short-grain mid-late maturing rice cultivar, was developed in 1990, more than 30 years ago. Despite its age, it has been the most widely grown cultivar in the Gyeongbuk province of South Korea for more than 25 years, making it the most important rice cultivar for the people of the Gyeongbuk province. The aim of this study was to analyze the relationship between the rice yield of “Ilpum’, the main rice cultivar in the Gyeongbuk province, and climate elements in the Daegu (southern plain area) and the Andong (inland mountainous area) regions in Gyeongbuk, South Korea. The rice yield over the past five years increased by about 13% and 24%, compared to that produced in the late 1990s in Daegu and the early 2000s in the Andong region, respectively. The number of panicles per hill and the grain ripening rate significantly affected rice yield in the ‘Ilpum’ cultivars in the Daegu region. The faster heading was a factor in the increase in ‘Ilpum’ rice yield in the Andong region. The air temperature has been rising and sunshine duration has been increasing from the late 1990s to present in both regions. Rice yield was evaluated to understand the effect of climate factors. The rice yields increased owing to the long sunshine duration during the grain-filling stage in both regions. In Andong, increasing the maximum temperature during the vegetative stage increased rice yield. Rising air temperature during the reproductive stage also increased rice yield. In particular, long sunshine hours throughout the whole rice growing period increased the rice yield of this cultivar in the Andong region. - COLLAPSE
    December 2020
  • Analysis of Varietal Differences in Pre-harvest Sprouting of Rice using RNA-Sequencing

    RNA-Sequencing을 이용한 벼 품종간 수발아 차이 분석

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

    최명구 ・ 이현석 ・ 황운하 ・ 양서영 ・ 이윤호 ・ 이충근 ・ 윤성중 ・ 정재혁

    Seed dormancy is an adaptive trait in which seeds do not germinate under unfavorable environmental conditions. Low dormancy seeds are easily germinated ... + READ MORE
    Seed dormancy is an adaptive trait in which seeds do not germinate under unfavorable environmental conditions. Low dormancy seeds are easily germinated under optimal environmental conditions, and these characteristics greatly reduce the yield and quality of crops. In the present study, we compared the pre-harvest sprouting (PHS) rate of two cultivars, Joun and Jopyeong, using the Winkler scale after heading day and temperature of the test. The PHS rate increased as the Winkler scale after heading day increased from 700°C to 1100°C and the temperature of the test increased. In all conditions, the PHS rate of Jopyeong was higher than that of Joun. RNA-sequencing was used to analyze the cause of the high PHS rate. We analyzed the biological metabolic processes related to the abscisic acid (ABA) metabolite pathway using the KEGG mapper with selected differentially expressed genes in PHS seeds. We found that the expression of ABA biosynthesis genes (OsNCEDs) was down-regulated and that ABA catabolic genes (OsCYP707As) was up-regulated in PHS seeds. However, the quantitative real-time PCR results showed that Joun had a higher expression of OsNCEDs than that of Jopyeong, but OsCYP707As did not yield a significant result. Joun displayed higher ABA content than that of Jopyeong not only during ripeness time but also during PHS treatment. Taken together, we provided evidence that the ABA content remaining in the seed is important to the PHS rate, which is determined by the expression level of the ABA biosynthesis gene OsNCEDs. - COLLAPSE
    December 2020
  • Effect of Transplanting Date on the Growth, Yield, and Occurrence of Viviparity in Floury Endosperm Rice Cultivars in the Chungbuk Province

    충북지역 쌀가루용 벼 품종의 이앙시기가 생육, 수량 및 수발아 발생에 미치는 영향

    Chae-Young Lee, Ye-Seul Choi, Hee-Du Lee, Taek-Gu Jeong, Ik-Jei Kim, Chung-Kon Kim, and Sun-Hee Woo

    이채영 ・ 최예슬 ・ 이희두 ・ 정택구 ・ 김익제 ・ 김정곤 ・ 우선희

    Rice consumption in Korea has been decreasing as the eating habits of the Korean people have diversified with rapid economic growth. Recently ... + READ MORE
    Rice consumption in Korea has been decreasing as the eating habits of the Korean people have diversified with rapid economic growth. Recently, floury endosperm rice cultivars were developed to boost rice consumption and replace wheat flour consumption with rice flour, which is vulnerable to viviparity under wet weather during the grain-filling stage because of its loosely packed starch granule structures. To overcome this limitation, it is necessary to find a suitable rice transplanting date to produce high-quality rice flour by altering the heading ecology type and changing the cultivation time by region. We examined four floury endosperm rice cultivars (FERC) in the Cheongju (central plain area) and Boeun (mid-mountainous area) regions of Korea from 2017 to 2019. Of the FERCs, the mid-late maturing types (MMT) Seolgaeng (SG), Hangaru (HGR), and Shingil (SGL) exhibited high yield and yield components after transplanting May 30 in both regions; the early maturing type (EMT) Garumi 2 (GRM2) also exhibited high yield after transplanting June 20 in Cheongju. In addition, MMTs showed the same tendency as the characteristics shown in Cheongju when grown in the Boeun region, and EMT displayed high yield and yield components after transplanting June 10. The FERCs could easily present pre-harvest sprouting in the rainy season during the grain-filling stage after 20 days post-heading because the mean temperature and frequency of more three-day rainfalls have increased over the last 5 years from the previous annual averages. Viviparity of HGR and GRM2 decreased as the transplanting date was delayed, with decreases of 2.3%–4.6% in HGR and 11.9%–23.1% in GRM2 according to the region. SGL was generally resistant to viviparity because of the Tongil type. To minimize pre-harvest sprouting and produce high yield of rice flour in the Chungbuk province, the most suitable transplanting time was the end of May in MMT and the middle and end of June in EMT. - COLLAPSE
    December 2020
  • Investigation of Changes in Grain Quality and Physicochemical Properties of Rice According to the Temperature during the Ripening Stage and Preharvest Sprouting

    벼 등숙기 기온 및 수발아가 종실 품질 및 이화학적 특성에 미치는 영향

    HyeonSeok Lee, YunHo Lee, WoonHa Hwang, JaeHyeok Jeong, SeoYeong Yang, ChungGen Lee, and MyoungGoo Choi

    이현석 ・ 이윤호 ・ 황운하 ・ 정재혁 ・ 양서영 ・ 이충근 ・ 최명구

    Studies on the occurrence of rice preharvest sprouting (PHS) have primarily focused on temperature and rainfall duration at the time of PHS ... + READ MORE
    Studies on the occurrence of rice preharvest sprouting (PHS) have primarily focused on temperature and rainfall duration at the time of PHS induction, but average temperature during grain filling can have a great influence on PHS. This study analyzed the effect of average temperature during grain filling on PHS occurrence and subsequent changes in grain quality after PHS. For two consecutive years, average temperature differences during grain filling were produced by varying the transplanting date. Artificial rainfall was treated under identical accumulated temperatures of 1200°C after heading. It was confirmed that the occurrence of PHS was higher under high average temperature conditions during grain filling. In addition, the degree of grain quality reduction caused by PHS occurred more severely under high temperature conditions during grain filling. In order to reduce the risk of PHS occurrence and subsequent quality damage, it is important to control the planting date to avoid high-temperature conditions during grain filling. - COLLAPSE
    December 2020
  • QTL Analysis to Improve and Diversify the Grain Shape of Rice Cultivars in Korea, Using the Long Grain japonica Cultivar, Langi

    초장립종 벼를 이용한 입형 관련 QTL 분석 및 국내 벼 품종 입형 개선 연구

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

    김석만, 박현수, 이창민, 백만기, 조영찬, 서정필, 정오영

    Rice grain shape is one of the key components of grain yield and market value. An understanding of the genetic basis of ... + READ MORE
    Rice grain shape is one of the key components of grain yield and market value. An understanding of the genetic basis of the variation in grain shape could be used to improve grain shape. In this study, we developed a total of 265 F2 individuals derived from a cross between japonica cultivars (Josaeng-jado and Langi) and used this population for quantitative trait locus (QLT) analysis. Correlation analysis was performed to identify relationships between grain traits (GL: grain length, GW: grain width, L/W: ratio of length to width, TGW: 1,000 grain weight). The grain shape was positively correlated with GL and TGW, and negatively correlated with GW. In QTL analysis associated with grain shape, one QTL for GL, qGL5, detected on chromosome 5, explained 20.3% of the phenotypic variation (PV), while two QTLs, qGW5 (PV=36.1) and qGW7 (PV=26.1), for GW were identified on chromosomes 5 and 7, respectively. Evaluation of the effects of each of the QTLs on the grain shape in the population showed a significant difference in the grain size in positive lines compared with the lines without the QTLs. According to the QTL combination of the allelic-types, the grain shape of the tested lines varied from semi-round type to long spindle-shaped type. The results of this study extend our knowledge about the genetic pool governing the diversity of grain shape in japonica cultivars and could be used to improve the grain shape of this species through marker-assisted selective breeding in Korea. - COLLAPSE
    December 2020
  • Development of Disease-resistant Japonica Rice Varieties and Effects of Pyramiding Resistance Genes

    내병성 자포니카 벼 계통 육성과 저항성 유전자 집적효과

    Woo-Jae Kim, Man-Kee Baek, Hyeon-Su Park, Geon-Mi Lee, Chang-Min Lee, Seok-Man Kim, Young-Chan Cho,Jeong-Phil Seo, and O-Young Jeong

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

    This study was carried out to develop a resistant variety against the K3a race of bacterial blight, Xanthomonas oryzae pv. oryzae, through ... + READ MORE
    This study was carried out to develop a resistant variety against the K3a race of bacterial blight, Xanthomonas oryzae pv. oryzae, through expansion and pyramiding of resistance genes. To develop an elite bacterial blight-resistant cultivar, the breeding process and bacterial blight resistance reactions in advanced backcross lines (ABLs) were analyzed. ABLs21 which contain Xa3 and Xa21, were developed by double backcrossing japonica cultivar Hwanggeumnuri, which has bacterial blight resistant Xa3 gene, and indica variety IRBB21, which havs Xa21 gene, followed by disease resistance bioassay and marker-assisted selection. The resistance genes of ABLs21 were amplified by PCR with the molecular markers 9643.T4 (Xa3) and U1/I1 (Xa21). Hwanggeumnuri and IRBB3 showed resistance reactions against K1, K2, and K3 races, and a susceptible reaction against K3a, K4, and K5 races. IRBB21 showed resistance reactions against K2, K3, K3a, K4 and K5 races, and a susceptible reaction against K1 race. Hwanggeumnuri showed susceptible reactions at the seedling, tillering and adult stages (all stages), whereas ABL21-1 showed moderate resistance at the tillering stage. ABL21-1 showed stable resistance against 18 isolates of K3a race, and the lesion length was shorter than that of the donor parents. In cluster analysis, the HB4032 isolate showed the highest pathogenicity among the 18 isolates. The molecular marker polymorphisms and average substituted chromosome segment lengths of ABLs21 were 63.2 % and 86.1 cM, respectively. Insertion of the donor chromosomal segments occurred in the predicted region of the Xa21 gene of ABLs21. - COLLAPSE
    December 2020
  • Review on Adaptability of Rice Varieties and Cultivation Technology According to Climate Change in Korea

    기후변화에 따른 국내 벼 품종과 재배기술의 적응성에 관한 고찰

    Myung-Chul Seo, Joon Hwan Kim, Kyeong Jin Choi, Yun-Ho Lee, Wan-Gyu Sang, Hyeon Suk Cho, Jung-Il Cho,Pyeong Shin, and Jae Kyeong Baek

    서명철 ・ 김준환 ・ 최경진 ・ 이윤호 ・ 상완규 ・ 조현숙 ・ 조정일 ・ 신평 ・ 백재경

    In recent years, the temperature of Korea has been rapidly increasing due to global warming. Over the past 40 years, the temperature ... + READ MORE
    In recent years, the temperature of Korea has been rapidly increasing due to global warming. Over the past 40 years, the temperature of Korea has risen by about 1.26°C compared to that in the early 1980s. By region, the west region of the Gangwon Province was the highest at 1.76°C and the Jeonnam Province was the lowest at 0.96°C. As the temperature continues to rise, it is expected that the rice yield will decrease in the future using the current standard cultivation method. As a result of global warming, the periods in which rice cultivation could be possible in regions each year has increased compared those to the past, showing a wide variety from 110 days in Taebaek to 180 days in Busan and Gwangyang. In addition, the transplanting time was delayed by 3-5 days in all regions. The average annual yield of rice showed an increasing trend when we analyzed the average productivities of developed varieties for cooked rice since the 1980s, especially in the early 1990s, which showed a rapid increase in productivity. The relationship between the average temperature at the time of development and the rice yield was divided into the periods before and after 1996. The higher the average temperature, the lower the yield of the developed varieties until 1996. However, since 1996, the increase in the average temperature did not show a trend in the productivity of the developed varieties. The climate change adaptability of developed rice varieties was investigated by analyzing the results of growing crops nationwide from 1999 to 2016 and the change in the annual yields of developed varieties and recently developed varieties as basic data to investigate the growth status of the crops in the country. As a result of annual comparisons of the yields of Taebongbyeo (2000) and Ungwangbyeo (2004) developed in the early 2000s for Odaebyeo, which was developed in the 1980s, the annual yields were relatively higher in varieties in the 2000s despite the increase in temperature. The annual yields of Samgwangbyeo (2003) and Saenuribyeo (2007), which were recently developed as mid-late-type varieties, were higher than those of an earlier developed variety called Chucheongbyeo, which was developed in the 1970s. Despite the rapid increase in temperature, rice cultivation technology and variety development are well adapted to climate change. However, since the biological potential of rice could reach its limit, it is necessary to develop continuous response technology. - COLLAPSE
    December 2020
  • Yield Response of Soybean [Glycine max (L.) Merrill] to High Temperature Condition in a Temperature Gradient Chamber
    Jae-Kyeong Baek, Wan-Gyu Sang, Jun-Hwan Kim, Pyong Shin, Jung-Il Cho, and Myung-Chul Seo
    Recently, abnormal weather conditions, such as extreme high temperatures and droughts, have increased in frequency due to climate change, there has accordingly ... + READ MORE
    Recently, abnormal weather conditions, such as extreme high temperatures and droughts, have increased in frequency due to climate change, there has accordingly been growing concern regarding the detrimental effects on field crop, including soybean. Therefore, this study was conducted to examine the effects of increased temperatures on soybean growth and yield using a temperature gradient chamber (TGC). Two major types of soybean cultivar, a medium- seed cultivar such as Daepung-2 and a large-seed cultivar such as Daechan, were used and four temperature treatments, aT+1°C (ambient temperature+ 1°C), aT+2°C (ambient temperature+2°C), aT+3°C (ambient temperature+3°C) and aT+4°C (ambient temperature+4°C) were established to examine the growth response and seed yield of each cultivar. Seed yield showed a higher correlation with seed weight (r=0.713***) and an increase in temperature affected seed yield by reducing the single seed weight. In particular, the seed growth rate of the large-seed cultivar (Daechan) increased at high temperature, resulting in a reduction in the number of days for full maturity. Our results accordingly indicate that large-seed cultivar, such as Daechan, is potentially vulnerable to high temperature stress. The results of this study can be used as basic data in the development of cultivation technology to reduce the damage caused by elevated temperatures. Also, further research is required to evaluate the response of each process contributing to seed yield production under high temperatures. - COLLAPSE
    December 2020
  • Effects of High Temperature and Drought on Yield and Quality of Soybean

    고온과 한발이 콩의 수량 및 품질에 미치는 영향

    Pyeong Shin, Wan-Gyu Sang, Jun-Hwan Kim, Yun-ho Lee, Jae-Kyeong Baek, Dong-Won Kwon, Jung-Il Cho, andMyung-Chul Seo

    신평 ・ 상완규 ・ 김준환 ・ 이윤호 ・ 백재경 ・ 권동원 ・ 조정일 ・ 서명철

    Currently, many studies are being conducted to cope with climate changes due to global warming and abnormal weather. The objective of this ... + READ MORE
    Currently, many studies are being conducted to cope with climate changes due to global warming and abnormal weather. The objective of this study was to investigate the effects of weather on the growth, yield components, and quality of soybeans using weather data from 2017 and 2018. The average temperature in 2018 was higher than that in 2017 from R1 to R5 of the growth stage for all cultivars. On the other hand, precipitation in 2018 was reduced compared to that in 2017 for Daewon and Daepung-2ho. It was observed that the flowering date in 2018 was earlier than that in 2017 for Daewon and Daepung-2ho, but the flowering date for Pungsannamul in 2018 was similar to that in 2017. Simulating soil water content with the estimation model (AFKAE0.5) determined that there were fewer drought dates in 2017 than those in 2018, and drought lasted from R1 to early R5 of the growth stage in 2018. Soybean growth in 2017 was better than that in 2018, and seed yield and 100-seed weight of soybean were higher in 2017 than those in 2018 for all cultivars. The seed size in 2017 was larger than that in 2018 for all cultivars. Oil content in 2017 was higher than that in 2018; in particular, the difference between both years was observed for Daewon and Daepung-2ho. Protein content was higher in 2018 than that in 2017; however, there were different levels for each cultivar. Thus, these results indicate that the yield component and quality of soybeans are affected by high temperature and drought. - COLLAPSE
    December 2020
  • Yield and Seed Quality Changes According to Delayed Harvest with Rainfall Treatment in Soybean (Glycine max L.)

    강우처리 및 수확 지연에 따른 콩 종실 특성 및 수량성 변화

    Inhye Lee, Min-Jung Seo, Myoung Ryoul Park, Nam-Geol Kim, Gibum Yi, Yu-young Lee, Mihyang Kim, Byong Won Lee, and Hong-Tae Yun

    이인혜 ・ 서민정 ・ 박명렬 ・ 김남걸 ・ 이기범 ・ 이유영 ・ 김미향 ・ 이병원 ・ 윤홍태

    Recently in Korea, soybean harvesting has been delayed due to rainfall during the harvesting season, resulting in a reduction in yield and ... + READ MORE
    Recently in Korea, soybean harvesting has been delayed due to rainfall during the harvesting season, resulting in a reduction in yield and seed quality. This study was conducted to analyze the changes in yield and seed quality during delayed harvest with rainfall treatment using different harvesting methods, including field harvesting and polyethylene film covering after cutting fully-matured soybean plants (PE covering after cutting), with two major Korean soybean cultivars (Glycine max L), Pungsannamulkong and Daewonkong. The shattering rate of Pungsannamulkong, which is higher than that of Daewonkong, increased up to 41.8% when the harvest was delayed for 40 days without rainfall treatment by harvesting with PE covering after cutting. The weight of 100 seeds tended to decrease slightly as harvesting was delayed. When Daewonkong was harvested using the PE covering after cutting method with rainfall treatment, the yield decreased to the lowest level with a 0.8 kg ha-1 daily reduction rate. Pungsannamulkong showed the lowest yield when harvested using PE covering after cutting without rainfall treatment with a 3.4 kg ha-1 daily reduction rate. The infected seed rate increased according to the harvest delay in both cultivars, and significant differences were observed according to rainfall treatment and harvesting method. The germination rate was maintained above 95% even after 40 days of delayed harvest if there was no rainfall treatment. However, with rainfall treatment, the germination rate was significantly lowered as harvesting time was delayed. In the field harvesting with rainfall treatment, the germination rate decreased to 77.2% for Daewonkong and 76.5% for Pungsannamulkong after 40 days of harvest delay. For the 100-seed weight, effects of individual treatments and interactions between treatments were not observed. In contrast, the effect of interactions between treatments on the shattering rate was significant in both cultivars, indicating that the shattering rate had the greatest impact on the yield changes during delayed harvest. - COLLAPSE
    December 2020
  • Evaluation of Tissue Culture Efficiency in a Speed Breeding System for Stable and Sustainable Supported Wheat (Triticum aestivum) Immature Embryogenesis

    안정적이며 지속적 밀(Triticum aestivum) 미성숙배 조직배양을 위한 스피드 브리딩 조건의 배양 효율 검정

    Geon Hee Lee, Tae Kyeum Kim, Chang Hyun Choi, and Jae Yoon Kim

    이건희 ・ 김태겸 ・ 최창현 ・ 김재윤

    Immature embryogenesis is a useful process in wheat tissue culture, including transgenic technology, because of its high regeneration efficiency compared to that ... + READ MORE
    Immature embryogenesis is a useful process in wheat tissue culture, including transgenic technology, because of its high regeneration efficiency compared to that in other tissues. However, it is a very labor-intensive and time-restrictive method, because the preparation of immature embryos is limited to the optimal time after flowering. In this experiment, ‘Speed Breeding’, a breeding technique that accelerates breeding generation advancement by extending the photoperiod, was applied to the wheat variety ‘Bobwhite’. A controlled growth room was constructed by adjusting the photoperiod (22-hour light/2-hour dark) using LED lights at temperature of 22°C. After vernalization of the Bobwhite seeds at 4°C for 4 weeks, the seedlings were grown in a controlled growth room and a greenhouse to compare the heading date. In both conditions, calli were induced from immature embryos on the 11th day after flowering. After 4 weeks, the calli were transferred to a regeneration medium. Regeneration efficiencies under greenhouse conditions and Speed Breeding conditions were determined as 45.05% and 43.18%, respectively. Antioxidant enzyme activity and reference gene expression analysis were performed to confirm the presence of stress due to an extremely long-day photoperiod. As a result, the antioxidant enzyme activity was not distinguished from that of the greenhouse condition. The reference gene expression analysis revealed that the PsaA and CDC genes were highly expressed under the Speed Breeding condition. However, expression of PsbA was similar expression in both conditions. These results will provide useful information for the application of immature embryogenesis to the wheat transformation system. - COLLAPSE
    December 2020
  • Changes in the Hyperspectral Characteristics of Wheat Plants According to N Top-dressing Rates at Various Growth Stages

    밀에서 질소 시비 조건에 따른 생육 단계별 초분광 특성 변화

    Jae Gyeong Jung, Yeong Hun Lee, Jae Eun Choi, Gi Eun Song, Jong Han Ko, Kyung Do Lee, and Sang In Shim

    정재경 ・ 이영훈 ・ 최재은 ・ 송기은 ・ 고종한 ・ 이경도 ・ 심상인

    Recently, wheat consumption has been increasing in Korea, requiring increased production. Nitrogen fertilization is a critical determinant in crop yield; therefore, it ... + READ MORE
    Recently, wheat consumption has been increasing in Korea, requiring increased production. Nitrogen fertilization is a critical determinant in crop yield; therefore, it is necessary to optimize the nitrogen fertilization regime with current trends that emphasize the minimum impact of nitrogen fertilizer on the environment. In this study, both nondestructive spectral analysis using a hyperspectral camera and growth analysis were performed to determine the optimal N top-dressing rates after heading. The nitrogen application regimes consisted of three conditions according to the secondary top-dressing rate: N4:3:0 (0 kg 10 a-1), N4:3:3 (2.73 kg 10 a-1), and N4:3:6 (5.46 kg 10 a-1). Subsequently, growth and physiological investigations were performed at the jointing, heading, and ripening stages of wheat, and spectral investigations were conducted. On April 29, as the nitrogen fertilization rate was increased to N4:3:3 and N4:3:6, plant height and grain yield increased by 4% and 8%, and 8% and 52%, respectively, compared to those under N4:3:0. Leaf area index and SPAD value also increased by 13% and 24%, and 32% and 43%, respectively. The R (red), G (green), and B (blue) of leaf color were lowered by 15, 11, and 4 in N4:3:3 and 44, 34, and 18 in N4:3:6, respectively, as compared to the control. Grain yield was the highest at high top-dressing (N4:3:6), however, there was no difference between no top-dressing (N4:3:0) and intermediat top-dressing (N4:3:3). The reflectance analyzed using a hyperspectral camera showed a difference in the near-infrared (NIR) region on March 19, and on April 29, there was a difference both in the visible light region greater than 550 nm and the NIR region. Vegetation indices differed according to fertilization regime, except for the greenness index (GI). The results of this study showed that not only growth and physiological analysis but also spectral indices can be used to optimize the nitrogen top-dressing rate. - COLLAPSE
    December 2020
  • Current Research Trends of Wheat Transformation and Biotechnology

    밀 형질전환과 이를 활용한 최신 연구동향

    Jae-Ryeong Sim, Sewon Kim, Su-Bin Lee, Beom-Gi Kim, Saet Buyl Lee, and Jong-Yeol Lee

    심재령 ・ 김세원 ・ 이수빈 ・ 김범기 ・ 이샛별 ・ 이종렬

    Wheat is one of the world's top three crops and is an important staple crop, accounting for 20% of the nutrient ... + READ MORE
    Wheat is one of the world's top three crops and is an important staple crop, accounting for 20% of the nutrient calories consumed by the world’s population. However, due to its complex heterogeneous hexaploid chromosomes and vast genome of approximately 16 Gb, compared to those of other crops, molecular biology and biotechnology studies on wheat are lacking. In recent years, wheat genome analysis has been performed using the latest next-generation sequencing technology so that useful genes can be easily obtained, and wheat biotechnology research is accelerating in various fields. In this review, wheat transformation, an indispensable technique for developing new functional biotech wheat by revealing the function of wheat genes, is described in detail. In addition, the latest research results for overcoming plant diseases, abiotic stresses, and wheat-related diseases that are difficult to solve by classical breeding through wheat transformation and biotechnology are described. - COLLAPSE
    December 2020
  • Effect of Zebularine Soaking on the Early Growth Stage and Mitotic Chromosomes of Barley (Hordeum vulgare L.)

    제부라린의 침종처리가 보리 생육초기 생장 및 체세포 염색체에 미치는 영향

    Ji-Yoon Han, Seong-Wook Kang, JaeBuhm Chun, Yang-Kil Kim, Young-Mi Yoon, and Seong-Woo Cho

    한지윤 ・ 강성욱 ・ 전재범 ・ 김양길 ・ 윤영미 ・ 조성우

    The objective of this study was to identify the effect of zebularine soaking on the early growth stage of barley (Hordeum vulgare ... + READ MORE
    The objective of this study was to identify the effect of zebularine soaking on the early growth stage of barley (Hordeum vulgare L.). Hence, root elongation was measured daily according to the different concentrations of zebularine (1.0, 2.5, 5.0, and 10.0 μM) for 4 days. On the first day, root length at 2.5 and 5.0 μM was significantly longer than that in the non-treated control. On the second day, root length was not significantly different among all concentrations and controls. On the third day, root elongation was suppressed by the effect of zebularine, except at 2.5 μM. The treatment time of zebularine accounted for the largest proportion of the variation in root elongation. After transplanting, plant growth velocity was similar to that of the control; however, plants at 2.5 μM showed faster growth velocity than that of the other concentrations and the control. In the metaphase of mitosis, most chromosomes of cells under zebularine treatment were ordinary regardless of the concentration, while some cells with short chromosomes were investigated at around 2%. The short chromosome showed a centromere. In addition, it showed short and long arms based on the centromere. The lengths of the short and long arms were different for each short chromosome. It is necessary to study the effect of the short chromosome as a chromosomal function on plant growth and phenotype through investigation of meiosis and fertilization at the chromosome level. - COLLAPSE
    December 2020
  • Development and Characterization of EMS-induced Mutants with Enhanced Salt Tolerance in Silage Maize

    EMS 유도 내염성 증진 사료용 옥수수 돌연변이체 선발 및 특성 분석

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

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

    Maize (Zea mays L.) is one of the most valuable agricultural crops and is grown under a wide spectrum of environmental conditions ... + READ MORE
    Maize (Zea mays L.) is one of the most valuable agricultural crops and is grown under a wide spectrum of environmental conditions. However, maize is moderately sensitive to salt stress, and soil salinity is a serious threat to its production worldwide. In this study, we used ethyl methane sulfonate (EMS) to generate salt-tolerant silage maize mutants. We screened salt-tolerant lines from 203 M3 mutant populations by evaluating the morphological phenotype after salt stress treatment and selected the 140ES91 line. The 140ES91 mutant showed improved plant growth as well as higher proline content and leaf photosynthetic capacity compared with those of wild-type plants under salt stress conditions. Using whole-genome re-sequencing analysis, 1,103 single nucleotide polymorphisms and 71 insertions or deletions were identified as common variants between KS140 and 140ES91 in comparison with the reference genome B73. Furthermore, the expression patterns of three genes, which are involved in salt stress responses, were increased in the 140ES91 mutant under salt stress. Taken together, the mutant line identified in our study could be used as an improved breeding material for transferring salt tolerance traits in maize varieties. - COLLAPSE
    December 2020
  • Productivity of Early Maturity Silage Corns during Continuous Monocropping

    조생종 사료용 옥수수 품종의 2기작 재배 시 생산성

    Beom-Young Son, Hwan Hee Bae, Young Sam Go, Sun-Lim Kim, and Seong Hyu Shin

    손범영 ・ 배환희 ・ 고영삼 ・ 김선림 ・ 신성휴

    This study evaluated the productivity of early maturity silage corns during continuous monocropping and the possibility of expanding forage production. Continuous monocropping ... + READ MORE
    This study evaluated the productivity of early maturity silage corns during continuous monocropping and the possibility of expanding forage production. Continuous monocropping of three silage corns, such as Kwangpyeongok (medium maturity), Sinhwangok (early maturity), and Sinhwangok2 (early maturity) was planted twice, in April and July from 2018 to 2019 at Suwon. The number of days from the sowing date to the silking date was 78 for the preceding crop and 52 for the succeeding crop. The number of days from the silking date to the harvesting date was 26 for the preceding crop and 46 for the succeeding crop. The sums of the temperature from the sowing date to the silking date were 1,512°C for the preceding crop, 1,246°C for the succeeding crop. The sums of the temperature from the sowing date to the harvesting date were 2,198°C for the preceding crop and 1,951°C for the succeeding crop. The dry matter yield of the preceding crop (1,637 kg/10a) was similar to that of the succeeding crop (1,565 kg/10a). The dry matter yields of Sinhwangok2 (1,673 kg/10a), Sinhwangok (1,660 kg/10a) and Kwangpyeongok (1,579 kg/10a) were similar to those of the preceding crop. The dry matter yields of Sinhwangok (1,669 kg/10a) and Kwangpyeongok (1,651 kg/10a) were similar to those of the succeeding crop and Sinhwangok2 (1,374 kg/10a) was the lowest among the three corn varieties. The total digestible nutrients (TDN) yield of the preceding crop (1,135 kg/10a) was similar to that of the succeeding crop (1,037 kg/10a). The TDN yields of Sinhwangok2 (1,183 kg/10a), Sinhwangok (1,158 kg/10a), and Kwangpyeongok (1,063 kg/10a) were similar to those of the preceding crop. The TDN yields of Sinhwangok (1,150 kg/10a) and Kwangpyeongok (1,100 kg/10a) were similar for the succeeding crop and Sinhwangok2 (970 kg/10a) was the lowest among the three corn varieties. The total dry matter yields of Sinhwangok (3,329 kg/10a) and Kwangpyeongok (3,230 kg/10a) were similar, but Sinhwangok2 (3,047 kg/10a) was the lowest among the three corn varieties. The total TDN yields of Sinhwangok (2,307 kg/10a), Kwangpyeongok (2,162 kg/10a), and Sinhwangok2 (2,152 kg/10a) were similar. It was concluded that Sinhwangok and Sinhwangok2 have high TDN yields as well as early maturity, and therefore are advantageous for direct continuous monocropping. - COLLAPSE
    December 2020
  • Changes in Growth Characteristics of Waxy Corn ‘Ilmichal’ due to Low Temperature during the Seedling Stage

    일미찰옥수수의 유묘기 저온에 따른 생육특성 변화

    Seung Ho Jeon, Seung Ka Oh, Han Yong Kim, Chae-In Na, Hui Su Bae, and Young Son Cho

    전승호 ・ 오승가 ・ 김한용 ・ 나채인 ・ 배희수 ・ 조영손

    To determine the damages to waxy corn caused by low temperature weather, we investigated the relationship between the temperature and duration of ... + READ MORE
    To determine the damages to waxy corn caused by low temperature weather, we investigated the relationship between the temperature and duration of low temperature treatment and the changes in growth characteristics during the recovery period after the treatments in different growth periods. Growth inhibition started in the low temperature group treated at temperatures below 5°C for three days. The inhibition ratio (IR) was more than 22% or more in all sample groups. As the treatment duration increased and the Temperature decreased, the growth was more greatly inhibited than that in the control. The IR was the highest at 27% or more in the 2nd leaf stage group treated at below 5°C for 5 days. The IR was in the order of 2nd leaf stage > 1st leaf stage > coleoptile. The IR during recovery was the highest in the 2nd leaf stage group treated at -3°C degree for 7 days, nd the values were 82% and 98% for NDVI and Fv/Fm, respectively. Especially, all groups treated at -3°C showed either no changes or decreases in the growth characteristics. As a result, growth inhibition increased as the temperature decreased, and as the duration of the low temperature increased. The degree of damage was in the order of 2nd leaf stage > 1st leaf stage > coleoptile. All early seedlings stopped growing and withered when exposed to temperatures at or below -3°C for 3 days or more. - COLLAPSE
    December 2020
  • Influence of Fertilization Treatment using Organic Amendment based on Soil Testing on Plant Growth and Nutrient Use Efficiency in Potato

    토양검정에 의한 유기자원 시비처방이 감자의 생육 및 양분이용효율에 미치는 영향

    Jin-Soo Lim, Bang-Hyun Lee, Seung-Hee Kang, and Tae-Guen Lee

    임진수 ・ 이방현 ・ 강승희 ・ 이태근

    In this study, we verified the effects of organic amendment application based on soil testing in potato cultivation. The application rate of ... + READ MORE
    In this study, we verified the effects of organic amendment application based on soil testing in potato cultivation. The application rate of organic amendments was determined based on the inorganicization rate of nitrogen, phosphoric acid, and potassium in the organic amendments. There was no significant difference in the length, stalk number, stalk diameter, and leaf color of potato plants under organic amendment application compared with those under chemical fertilization. The quantity of potato tubers and yield of marketable tubers under organic amendment application were higher than those under chemical fertilization. The top fresh weight and top-to-root ratio were the highest under organic amendment application, followed by those under chemical fertilization and the control. The inorganic nitrogen content in the leaves and stems of potato plants was the highest under chemical fertilization. There was no difference in the phosphoric acid content between the potatoes under chemical fertilization and those under organic amendment application. The potassium content in potatoes was higher under chemical fertilization than that under organic amendment application. While the change trend of inorganic nitrogen content in the roots was similar to that in the leaves and stems, the potatoes under organic amendment application, with the highest yield, showed the highest dry weight. The tuber weight showed a positive correlation with plant length, stalk number, and stalk diameter. The higher the weight of the tuber, the higher the weight of the marketable tuber, and the higher the top fresh weight, the higher the yield. Therefore, to increase yield, it is necessary to supply nutrients to improve the top fresh weight to the optimal level. There was no difference in the utilization efficiency of nitrogen and potassium between the potatoes under chemical fertilization and those under organic amendment application. The utilization efficiency of phosphoric acid was increased by 0.1% in potatoes under organic amendment application compared with that under other treatments. Regarding soil chemistry after harvest, the soils under organic amendment application showed a higher electrical conductivity and higher nitrogen and phosphoric acid content than those under other treatments. Therefore, the organic amendment method used in this study can be an alternative to chemical fertilization. It is also advantageous for the cultivation of subsequent crops in potato fields. - COLLAPSE
    December 2020
  • Genetic Diversity and Population Structure of Peanut (Arachis hypogaea L.) Accessions from Five Different Origins
    Kunyan Zou, Ki-Seung Kim, Daewoong Lee, and Tae-Hwan Jun
    Peanut is an allotetraploid derived from a single recent polyploidization. Polyploidization has been reported to have caused significant loss in genetic diversity ... + READ MORE
    Peanut is an allotetraploid derived from a single recent polyploidization. Polyploidization has been reported to have caused significant loss in genetic diversity during the domestication of cultivated peanuts. Single nucleotide polymorphism (SNP)-based markers such as cleaved amplified polymorphic sequences (CAPS) derived from next-generation sequencing (NGS) have been developed and widely applied for breeding and genetic research in peanuts. This study aimed to identify the genetic diversity and population structure using 30 CAPS markers and 96 peanut accessions from five different origins. High genetic dissimilarities were detected between the accessions from Korea and those from the other three South American origins generally regarded as the origin of peanuts, while the accessions from Brazil and Argentina presented the lowest genetic dissimilarity. Based on the results of the present study, accessions from Korea have unique genetic variation compared to those from other countries, while accessions from the other four origins are closely related. Our study identified the genetic differentiation in 96 peanut accessions from five different origins, and this study also showed the successful application of SNP information derived from re-sequencing based on NGS technology. - COLLAPSE
    December 2020
  • Comparison of Chemical Constituents in Mung bean (Vigna radiata L.) Flour between Cultivation Regions and Seeding Dates
    Yeon Ju An, Mi Jung Kim, Sang Ik Han, Hee-Youn Chi, Chang Kwon, So Yeon Kim, Yu Jin Yang, Yun Ju Kim,Hee Sung Moon, Seung-Hyun Kim, and Ill-Min Chung
    Legumes are one of the largest families of crop plants and are widely consumed and produced for their nutritional and commercial benefits ... + READ MORE
    Legumes are one of the largest families of crop plants and are widely consumed and produced for their nutritional and commercial benefits. Mung bean (Vigna radiata L.) is a legume crop that contains various functional compounds ; moreover, it has strong antioxidant properties and is becoming an increasingly important food crop. However, most previous studies on mung beans have focused on their primary metabolites. In this study, we investigated the composition and contents of phenolic compounds, fatty acids, soyasapogenol and tocopherol in mung beans cultivated in different regions and cultivated at different seeding dates. Material analysis was conducted using the following methods: LC-MS/MS, GC-FID and HPLC-ELSD. In total, 57 different samples were analyzed. Thirteen phenolic compounds were detected in mung beans. Of these, vitexin and isovitexin were the most abundant compounds, accounting for approximately 99% of phenolic compounds. The difference in phenol compounds according to the seeding dates of mung bean was not statistically significant. The total fatty acid content in beans was the highest in Pyeongchang. Significant differences in total fatty acid content were found according to the cultivation regions. Crops grown in Sohyeon and Dahyeon showed the highest soyasapogenol B content in the Suwon region, and these were the lowest in Jeonju. The total tocopherol content of beans cultivated in Dahyeon and Sohyeon was the lowest and highest in Pyeongchang. Soyasapogenol B and total tocopherol content were not significantly different according to seeding dates. This study was conducted to obtain basic data for the cultivation of mung beans with a high content of various functional materials in terms of regional specialization and optimal seeding time. - COLLAPSE
    December 2020
  • Effect of LED Light Intensity on Seedling Quality and Tuber Production of Potato Stem Cuttings Grown in a Closed-Type Plant Production System

    폐쇄형식물생산시스템을 이용한 감자 경삽묘 육묘시 묘소질과 괴경 생산에 대한 LED 광도의 영향

    Man Hyun Jo, In Ki Ham, Kwon Seo Park, and Ji Hong Cho

    조만현 ・ 함인기 ・ 박권서 ・ 조지홍

    This study was performed to establish light intensity conditions for producing stem cuttings for aeroponic systems suitable for seed potato production using ... + READ MORE
    This study was performed to establish light intensity conditions for producing stem cuttings for aeroponic systems suitable for seed potato production using a closed-type plant production system. Shoot tip cultured plantlets of ‘Sumi’ and ‘Chubaek’ potato (Solanum tuberosum L.) were acclimatized, cuttings were collected, and stem cuttings were planted. The seedlings were raised for 40 days at different LED light intensities (60, 120, 180, and 240 μmol·m-2·s-1), and were cultivated in an aeroponic system for 80 days. When stem cuttings were raised at 60 μmol·m-2·s-1 LED light intensity, the plant height was the longest, at 17.3 cm for ‘Sumi’ and 16.1 cm for ‘Chubaek’, and the number of nodes was the highest in both cultivars. The higher light intensities, produced smaller plants with fewer nodes. The leaf areas, SPAD values, and Fv/Fm values differed slightly between cultivars. The fresh weight of stem cuttings, and the production rate of healthy stem cuttings were the highest at 60 µmol·m-2·s-1. In the aeroponic system, seedlings raised at 60 μmol·m-2·s-1 with LED light intensity showed a difference between the cultivars, but the fresh weight of stems and leaves above the planting plate was the heaviest. In addition, below the planting plate the stem cuttings were longest and the root weight was heaviest at 60 μmol·m-2·s-1 LED light intensity. The number of stolons also differed between cultivars, but was greatest for seedlings raised at 60 μmol·m-2·s-1 LED light intensity, at 4.2/plant for ‘Sumi’ and 7.7/plant for ‘Chubaek’. At 60 μmol·m-2·s-1 LED light intensity, the tuber number and total tuber weight were the best, but the higher the light intensity, the smaller the total tuber number and total tuber weight for both cultivars. In conclusion, when producing potato stem cuttings for aeroponic systems using a closed-type plant production system, the most suitable LED light intensity for raising seedlings was found to be 60 μmol·m-2·s-1. - COLLAPSE
    December 2020
  • Effects of the Slow-releasing Fertilizer and Sowing Date on Waxy Corn “Mibaek 2” Propagated through Double Cropping without Tillage in the Middle Region of Korea
    Jae-Wung Lee, Se-Gu Hwang, Hye-Rim Moon, Ik-Jei Kim, and Young-Ho Kim
    This study was conducted to investigate the effects of slow-releasing fertilizer and sowing date on waxy corn propagated through double cropping without ... + READ MORE
    This study was conducted to investigate the effects of slow-releasing fertilizer and sowing date on waxy corn propagated through double cropping without tillage. “Mibaek 2” was sown for first cropping on March 25th, April 5th , and April 15th, and for second cropping on July 5th, July 15th, and July 25th in 2018-2019. In order to save labor, slow-releasing fertilizer was utilized only one time before sowing. The accumulated temperature from sowing to silking was about 590-700℃. It took 65-77 days when “Mibaek 2” was sown in early April, but the one sown in early July took 42-52 days. In the first cropping, the culm length and ear length caused by the sowing date had no statistical significance, but the kernel set length was the highest at 123 cm in the sowing district on April 5th. The weight of marketable ears was the highest at 100%, in addition to soil testing-based recommended fertilization. Meanwhile, in the second cropping, culm length, ear length, and yield were less compared to the first cropping. The culm length, kernel set length, ear length, and seed set length decreased as sowing date was delayed. The number and yield of marketable ears were the highest at 100%, in addition to soil testing-based recommended fertilization like in the first cropping. It has been found that securing yield by July 15th to finish the second seeding of the crop in the central part of Korea is advantageous. These results of this study will be helpful to farmers for the double cropping of waxy corn cultivation and management. - COLLAPSE
    December 2020
  • Evaluation of Morphological Traits and Genetic Composition in Melon Germplasm

    멜론 유전자원의 형태적 특성 및 유전적 구성 평가

    Seungbum Lee, Ik Jang, Do Yoon Hyun, Jung-Ro Lee, Seong-Hoon Kim, Eunae Yoo, Sookyeong Lee, Gyu-Taek Cho, andKyung Jun Lee

    이승범 ・ 장익 ・ 현도윤 ・ 이정로 ・ 김성훈 ・ 유은애 ・ 이수경 ・ 조규택 ・ 이경준

    Melon (Cucumis melo L.), one of the most important fruit crop species, is cultivated worldwide. In this study, a total of 206 ... + READ MORE
    Melon (Cucumis melo L.), one of the most important fruit crop species, is cultivated worldwide. In this study, a total of 206 melon accessions conserved at the National Agrobiodiversity Center (NAC) in RDA were characterized for nine morphological characteristics according to the NAC descriptor list. In addition, to confirm the genetic composition of each melon accession, genetic profiling was performed using 20 SSR markers. Among the 206 melon accessions, 159 (77.2%) were collected from Asia. The color of fruit flesh and skin were mostly ‘white’ (56.0%) and ‘green’ (49%), respectively. Days to female flowering (FD) and maturity (MD) of the accessions ranged from 58 to 72 and 17 to 63, respectively. The fruit length and width of the accessions ranged from 6.0 to 29.3 and 3.6 to 17.2 cm, respectively. The sugar content (SU) ranged from 2.5% to 13.2% with an average of 7.0%. In correlation analysis, SU showed positive and negative correlations with MD and FD, respectively. The accessions were classified into four clusters by cluster analysis. From the results of genetic profiling using 20 SSR markers, three accessions (K189118, K100486, and K190292) were expected to be inbred lines among 206 melon accessions. These results could expand the knowledge of the melon germplasm, providing valuable material for the development of new melon varieties to suit consumer tastes. - COLLAPSE
    December 2020
  • Development of Real-time Quantitative PCR Assay based on SYBR Green I and TaqMan Probe for Detection of Apple Viruses

    사과 바이러스 검정을 위한 SYBR Green I 및 TaqMan probe 기반의 real-time PCR 검사법 개발

    Seong Heo and Yong Suk Chung

    허성 ・ 정용석

    Virus infections of apples result in lowered commercial qualities such as low sugar content, weakened tree vigor, and malformed fruits. An effective ... + READ MORE
    Virus infections of apples result in lowered commercial qualities such as low sugar content, weakened tree vigor, and malformed fruits. An effective way to control viruses is to produce virus-free plants based on the development of an accurate and sensitive diagnostic method. In this study, real-time PCR assays based on SYBR Green I and TaqMan probes were developed for detecting ASGV, ASPV, and ApMV viruses. These methods can detect and quantify 103 to 1011 RNA copies/μL of each virus separately. Compared with methods with two different dyes, the SYBR Green I-based method was efficient for virus detection as well as for assay using the TaqMan probe. Field tests demonstrated that real-time PCR methods developed in this study were applicable to high-throughput diagnoses for virus research and plant quarantine. - COLLAPSE
    December 2020
  • Changes in Chemical Properties and Effect on Germination of Radish Seed from Aeration of Co-digestate Fertilizers

    통합 혐기소화액별 폭기처리에 따른 화학적 성분 변화와 무의 발아효과

    Ji-Eun Byeon, Hong-Ju Lee, Jong-Won Ryoo, and Sun-Goo Hwang

    변지은 ・ 이홍주 ・ 류종원 ・ 황선구

    This study aimed to determine the minimum period of aeration treatment of co-digestate to develop it as liquid fertilizer and the chemical ... + READ MORE
    This study aimed to determine the minimum period of aeration treatment of co-digestate to develop it as liquid fertilizer and the chemical changes that occur in the aerobic liquefying process. The co-digestates were divided into three types depending on their additives: swine slurry anaerobic digestate (SS AD), swine slurry 70% + cow slurry 30% anaerobic digestate (SS + CS AD), and swine slurry 70% + apple pomace 30% anaerobic digestate (SS + AP AD). The pH of all co-digestates increased rapidly after 3 days of aerobic treatment, but had slightly decreased in SS AD after 9 days and in SS + CS AD and SS + AP AD after 15 days. All co-digestates showed a strongly reduced pH between 27 and 36 days of aeration treatment. SS AD had lower pH value, dissolved oxygen (DO), NH4-N, and NO3-N content under aerobic conditions than other co-digestates. To assess the fully decomposed liquid fertilizer, a germination test was performed on the undiluted and diluted co-digestate using the liquid fertilizer germination index (LFGI) method. The relative germination ratio, relative root elongation, and germination index of SS AD were higher than those of the others. When the LFGI method was used for the germination test, all co-digestates showed an appropriate germination index of 70 after 60 days of aeration treatment. Thus, we suggest that the minimum period of aeration treatment for co-digestates might be 60 days to develop the fully decomposed liquid fertilizer. - COLLAPSE
    December 2020