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Research Article
- Application of a Polyphosphate Fertilizer Treatment Enhances the Growth Rate of Lettuce Seedlings in a Commercial Plant Factory
- Kwang Sup Lyu, Hee Sung Hwang, Hyeon Woo Jeong, Seung Jae Hwang
- Several commercial plant factories cultivate lettuce, and the crop growth rate is an important factor related to profitability. The early development of …
- Several commercial plant factories cultivate lettuce, and the crop growth rate is an important factor related to profitability. The early development of lettuce is affected by phosphorus uptake, and plants absorb polyphosphates more stably than they do monophosphates. This study was conducted to evaluate the growth rate of lettuce (Lactuca sativa L. ‘Caipira’) during a polyphosphate treatment. Phosphorus was used in various combinations with potassium monophosphate (KH2PO4) and potassium polyphosphate (K5P3O10), specifically 32.4 + 15 (M2P1), 16.6 + 29.9 (M1P2), and 0.1 + 44.9 (M0P3) mg·L-1, and 48 mg·L-1 KH2PO4 as the control. The leaf length, leaf width, leaf area, and fresh and dry weights increased significantly with high polyphosphate concentrations (M0P3). The growth rate of the roots, the total root length, the root surface area, and the number of root tips were significantly increased in M0P3. Leaf growth was significantly different in the later stages of lettuce growth, whereas root growth was significantly different in the early stages. The results of this study suggest that the growth rate of lettuce can be improved by increasing the polyphosphate concentration, which could positively affect the profitability of commercial plant factories. - COLLAPSE
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Research Article
- Packaging Container Effects on Fruit Quality Attributes, Mechanical Injury and Physiological Disorders in Hardy Kiwifruit Cultivars under a Simulated Handling System
- Hyowon Park, Theint Thandar Latt, Sangyo Jeong, Si-Eun Byeon, Jinhee Lee, Hnin Phyu Lwin, Hyun Ji Eo, Chul-Woo Kim, Uk Lee, Jinwook Lee
- Fruit of hardy kiwifruit is highly susceptible to physiological disorders and mechanical damage during handling and transport when packed in conventional clamshell …
- Fruit of hardy kiwifruit is highly susceptible to physiological disorders and mechanical damage during handling and transport when packed in conventional clamshell containers. Thus, this study assessed the impact of different packaging containers on fruit quality attributes, mechanical injuries, and physiological disorders of ‘Autumn Sense’ and ‘Daebo’ hardy kiwifruit cultivars stored at 22°C for 7 d of shelf life and 3 d of shelf life after 7 d of cold storage at 10°C. During the shelf life, fruit weight loss was highest in the pressed pulp egg tray but lowest in the 10-cavity container for both cultivars. The soluble solids content (SSC) increased, whereas the flesh firmness and titratable acidity (TA) decreased. Thus, the SSC/TA ratio increased, irrespective of the packaging container and cultivar. Ethylene production was highest in the clamshell container but lowest in the 10-cavity container in the ‘Autumn Sense’ cultivar. Fruit peel color variables were lowest in the clamshell container for the ‘Autumn Sense’ cultivar but were inconsistent in the ‘Daebo’ cultivar. Fruit bruising, wounding, and softening were highest in clamshell containers for both cultivars, whereas fruit shriveling was highest in the pressed pulp egg tray. Fruit spoilage was highest in the clamshell container for both cultivars. After 3 d of shelf life following cold storage, fruit weight loss remained the highest in the pressed pulp egg tray and the lowest in the 10-cavity container in both cultivars. Although the firmness and TA declined sharply, the SSC increased substantially, resulting in a higher SSC/TA ratio. The SSC/TA ratio was higher in the ‘Autumn Sense’ cultivar than in the ‘Daebo’ cultivar, regardless of the packaging container. The ethylene level was negligible in the ‘Daebo’ cultivar and highest in the pressed pulp egg tray but lowest in the 10-cavity container in the ‘Autumn Sense’ cultivar. Fruit bruising, wounding, and softening were most prevalent in the clamshell and pressed pulp containers for both cultivars. Fruit shriveling, peel browning, and overall fruit spoilage were highest in the pressed pulp egg tray for the ‘Autumn Sense’ cultivar and the pressed pulp container for the ‘Daebo’ cultivar. Therefore, the results indicate that a 10-cavity container could be more suitable for the packaging and handling of hardy kiwifruit. - COLLAPSE
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Research Article
- Effects of Processed Red-clay and Microbial Fertilizer Containing Lactobacillus fermentum on Tomato Growth Characteristics, and Fruit Quality Levels
- Sora Lee, Songhee Lee, Hyung Won Lee, Hyeonsoo Jang, Wonwoo Cho, Ganchudur Tsetsegmaa, Hoduck Kang, Hyunmo Choi
- Global agricultural practices emphasize the demand for environmentally friendly and sustainable production strategies. Therefore, this study investigated the impact of processed red …
- Global agricultural practices emphasize the demand for environmentally friendly and sustainable production strategies. Therefore, this study investigated the impact of processed red clay (PRC), an eco-friendly material derived from red clay, and a microbial fertilizer containing Lactobacillus fermentum (MFcL) on tomato growth, fruit quality levels, and soil properties. Tomatoes were transplanted and cultivated in open-field experiments. PRC, MFcL, and PRC+MFcL treatments were applied at 500 mL·plant-1 four times at seven-day intervals. The chlorophyll content of tomato leaves decreased over time, with MFcL significantly affecting the chlorophyll content and photosynthetic quantum yield (Fv/Fm). Significant differences in certain fruit growth traits, including the fruit width, weight, and fruit shape index, were observed among the treatments. Significant variations (p < 0.05) in the total yield and fruit cracking percentage were also found between the non-fertilizer (NF) and PRC treatments. The application of PRC significantly reduced the fruit cracking percentage and enhanced the crude protein and fat content of the fruits compared to the NF treatment. In addition, MFcL significantly increased the soil-available phosphorus content and decreased pH levels, and PRC+MFcL promoted rhizobacterial growth, showcasing the potential of these biofertilizer treatments. The combined treatment of PRC and MFcL proved effective for growing tomatoes in open-field conditions. Further research should explore various PRC and microorganism combinations to gain a comprehensive understanding and to assess the potential of their rational application to crops. - COLLAPSE
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Research Article
- Temperature-Mediated Alterations in the Growth, Physiology, Morphology, and Pharmacology of Astragalus membranaceus Bunge: Implications for Medicinal Herb Cultivation and Therapeutic Efficacy
- Myeong Ja Kwak, Yong-il Kim, Jongkyu Lee, Jooyoung Kim, Eunji Kim, Dawon Kang, Wontae Choi, Su Young Woo
- Climate change is known to affect the physiobiochemical aspects of plants throughout their life cycles, including their growth and maturation stages. This …
- Climate change is known to affect the physiobiochemical aspects of plants throughout their life cycles, including their growth and maturation stages. This study was conducted to assess the influence of different temperatures on the growth characteristics, physiological responses, leaf surface microstructure, and pharmacological properties of Astragalus membranaceus Bunge (Hwang-gi) cultivated in a temperature-gradient greenhouse (T1, control; T2, moderate increase; T3, high increase; and T4, extreme increase). As the temperature was increased, there was a pronounced decrease in the soil moisture content, leading to alterations in the growth patterns of Hwang-gi. Specifically, a reduction in the chlorophyll content was observed, resulting in diminished photosynthetic capacity. Additionally, changes in leaf surface microstructures indicated adaptive strategies aimed at minimizing moisture loss, such as an increase in the trichome density and a reduction in the pore size. Moreover, a pharmacological analysis of Hwang-gi roots showed that the contents of certain secondary metabolites, in this case astragaloside I, calycosin-7-O-glucoside, and formononetin, were significantly altered by temperature stress. These findings suggest that climate change poses a potential threat to the growth, physiological function, and pharmacological quality of Hwang-gi, highlighting the need for adaptive strategies to protect this valuable medicinal herb. - COLLAPSE
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Research Article
- Phenylpropanoid Accumulation and Gene Expression in Agastache rugosa Leaves and Flowers Stages
- Su Been Hwang, Jeongyeo Lee, Vu Phong Lam, Jong Seok Park
- Agastache rugosa is a medicinal plant that belongs to the Lamiaceae family of plants and is most commonly found in Korea. It …
- Agastache rugosa is a medicinal plant that belongs to the Lamiaceae family of plants and is most commonly found in Korea. It contains various phenolic compounds with antifungal and anti-human immunodeficiency virus properties. This study aimed to investigate changes in the phenylpropanoid levels and the transcript levels of phenylpropanoid biosynthetic genes in the leaves, flowers, and roots of A. rugosa at different developmental stages. After 39 days of growth, plants were collected at designated time points. The harvested samples were subsequently subjected to an analysis. High-performance liquid chromatography (HPLC) was employed to assess the chemical composition, while quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to evaluate the gene expression levels. The concentration of rosmarinic acid (RA) increased steadily as the leaves and flowers developed, whereas the concentrations of tilianin and acacetin decreased. Among the different developmental stages of the leaves, flowers and root, L5 (leaf size of 9 cm) showed the highest levels of RA (15.5 mg·g-1), while L1 showed the highest levels of tilianin and acacetin (4.9 and 1.7 mg·g-1, respectively). F4 (full flowering) showed the highest levels of RA (6.5 mg·g-1), tilianin (6.6 mg·g-1), acacetin (6.8 mg·g-1). The roots of A. rugosa contained only RA (12.1 mg·g-1). A. rugosa leaves in the L1 phase exhibited significant expression levels of genes related to the phenylpropanoid biosynthesis of Tilianin, including ArPAL, ArC4H, ArCHS, and ArCHI. In this study, we identified and quantified health-promoting compounds in the leaves and flowers of Agastache rugosa. Our research findings endorse the medicinal potential of A. rugosa while also highlighting specific areas for enhancing the production of tilianin, acacetin, and rosmarinic acid within this plant. - COLLAPSE
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Research Article
- Effects of Histological Characteristics of the Leaves and the Microclimate on Disease Development Patterns in Chungjin, a Ginseng Cultivar Resistant to Leaf Blight Caused by Alternaria Panax
- Joon Soo Lee, Hye Sun Cho, Jeong Sup Shin, Chol Soo Park, Hee Jun Ahn
- The occurrence of Alternaria leaf blight is known to reduce ginseng yields by 10-30%. To prevent the disease, agricultural pesticides are applied …
- The occurrence of Alternaria leaf blight is known to reduce ginseng yields by 10-30%. To prevent the disease, agricultural pesticides are applied nine to twelve times a year. However, the repeated use of the same type of pesticides increases the incidence of pesticide resistant strains, disrupting the entire ecosystem. Addressing this issue requires the development of a new ginseng cultivar that is resistant to Alternaria leaf blight. To this end, Chungjin, a cultivar resistant to leaf blight, and Sunone, a cultivar susceptible to the disease, were examined using detached leaf methods. The examination covered a wide range of factors and topics, including the optimization of conditions for early diagnosis testing, the relationship between leaf cuticles and disease development, the correlation between microclimate conditions under the shade and disease development, and changes in the yield of ginseng resulting from reduced pesticide application. The optimal conditions for early diagnosis testing were determined as follows: adaxial leaf surfaces were inoculated with a conidial suspension containing a concentration of 1 × 105 spores/mL. Subsequently, the leaves were incubated at a temperature of 20°C and relative humidity of 70% for eight days. The delayed development of Alternaria blight in Chungjin is attributed to the presence of well-developed leaf cuticles. Among the weather conditions considered here, rainfall exhibited the highest correlation with disease development, followed by temperature. High relative humidity was found to have little correlation. Despite the fact that pesticides were applied only twice in a period from July to late August, Chungjin also had 22% more yield. Chungjin reduces the required amount of pesticide application, thereby preventing the emergence of pesticide resistant strains and contributing to environmental protection. The major findings of this study are expected to serve as foundational data for further research on leaf blight resistance and agronomic control. - COLLAPSE
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Research Article
- Development of Single-Nucleotide Polymorphism Markers for Seed Coat Color in Watermelon
- Yoon Jeong Jang, Ki Ryong Kim, Jisu Ryu, Yongjae Kim, Sang-Min Chung, Gung Pyo Lee
- Seed coat color affects water absorption, gas diffusion, seed dormancy, seed quality, germination, and seedling appearance. These attributes of watermelon seeds thus …
- Seed coat color affects water absorption, gas diffusion, seed dormancy, seed quality, germination, and seedling appearance. These attributes of watermelon seeds thus necessitate the establishment of watermelon breeding programs that produce desired seed coat colors. However, the hereditary and molecular mechanisms underlying this feature remain unknown. Here, we aimed to identify the genomic region responsible for seed coat color in watermelon and to design single-nucleotide polymorphism (SNP) markers that are closely associated with this characteristic. We crossed two inbred lines, RG-21 (white seed coat, WSC) and Wr-609 (red seed coat, RSC), to generate F1 hybrids (tan seed coat) and F2 populations for locus mapping and a SNP marker analysis. Our findings indicated that the F2 seed coat color is controlled by negative epistasis-expressing WSC. A bulked segregant analysis combined with Illumina whole-genome resequencing revealed a putative causative genomic area for WSC at 5.1–9.7 Mb on chromosome (Chr.) 6 and RSC at 3.6–7.7 Mb on Chr. 5. Based on the four-gene hypothesis, the genotypes of the WSC, RSC, and F1 hybrids were Rtwd, rtWd, and RtWd, respectively. We then applied 19 high-resolution melting markers to 106 F2 progeny to identify the causative genomic regions. We created a strongly co-segregated SNP marker for WSC at 6.9–7.1 Mb on Chr. 6 and RSC at 4.2–4.8 Mb on Chr. 5. Our findings serve as a basis for utilizing seed coat color in watermelon breeding programs and for expediting F1 cultivar generation. - COLLAPSE
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Research Article
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Proper Day and Night Temperatures for Different Cultivars of Cucumber Seedlings after the Grafting Stage
접목 후 오이 묘의 품종별 적정 주간 및 야간온도
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So Yeong Hwang, Ji Hye Yun, Jin Yu, Jeong Hun Hang, Eun Won Park, Hyeon Woo Jeong, Hee Sung Hwang, Seung Jae Hwang
황소영, 윤지혜, 유진, 황정훈, 박은원, 정현우, 황희성, 황승재
- This study was conducted to investigate the growth characteristics of different cultivars of grafted cucumber (Cucumis sativus L.) seedlings when affected …
본 연구는 온도에 따른 오이 접목묘의 품종별 생육 특성을 조사하고, 접목 활착 후 적정 주야간온도를 구명하기 위해 수행되었다. 오이(Cucumis sativus L.) …
- This study was conducted to investigate the growth characteristics of different cultivars of grafted cucumber (Cucumis sativus L.) seedlings when affected by different temperature conditions and to identify the optimal day and night temperatures after the grafting stage. Three cucumber cultivars were used, ‘NakWonSeongcheongjang, NS’, ‘Sinsedae, SD’, and ‘Goodmorning backdadagi, GB’, with seedlings as scions grafted onto a figleaf gourd (Cucurbita ficifolia ‘Heukjong’) seedling as the rootstock. Experiment 1 investigated the appropriate air temperature by assessing growth characteristics as affected by different temperatures, in this case 18, 23, and 28℃ (24 h). Experiment 2 investigated growth characteristics as affected by the night temperature. Based on the results of experiment 1, the day temperature was fixed at 28℃, which was best for growth, and the night temperatures then assessed were 15, 20, and 25℃ (12/12 h). Root and shoot growth levels of all cultivars were promoted when the air temperature was 28℃, and the seedling period could be effectively shortened. On the other hand, the optimal night temperature differed significantly depending on the cultivar. ‘NS’ and ‘SD’ showed inhibited respiration when the night temperature was 15℃, with significantly decreased plant heights and leaf areas and increased shoot dry weights. Also, the seedling quality was high at 15℃. On the other hand, the growth of ‘GB’ was significantly promoted at 25℃ and the seedling quality was also high. Therefore, it is considered that the optimal day/night temperatures of cucumber seedlings after the grafting stage are 28/15℃ for ‘NS’ and ‘SD’ and 28/25℃ for ‘GB’.
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본 연구는 온도에 따른 오이 접목묘의 품종별 생육 특성을 조사하고, 접목 활착 후 적정 주야간온도를 구명하기 위해 수행되었다. 오이(Cucumis sativus L.) 접수는 낙원성청장(NakWonSeongcheongjang, NS), 신세대(Sinsedae, SD), 그리고 굿모닝백다다기(Goodmorning backdadagi, GB) 품종이 사용되었으며, 박과 대목인 흑종호박(Cucurbita ficifolia ‘Heukjong’)에 접목되었다. 실험 1은 온도에 따른 생육 특성을 조사하여 적절한 주간온도를 구명하기 위해 수행되었고, 온도는 각각 18, 23, 그리고 28°C(24h)로 설정하였다. 실험 2는 야간온도에 따른 생육 특성을 조사하였다. 실험 1의 결과를 토대로, 주간온도는 생육이 가장 양호하였던 28°C로 고정한 후, 야간온도를 각각 15, 20, 그리고 25°C(12/12h)로 설정하였다. 지하부와 지상부의 생육은 모든 품종에서 온도가 28°C였을 때 촉진되었고, 육묘 기간을 효과적으로 단축시킬 수 있었다. 반면에, 적정 야간온도는 품종별로 유의적인 차이가 나타났다. ‘NS’와 ‘SD’는 야간온도 15°C에서 호흡이 억제되어 초장과 엽면적이 유의적으로 감소하였고, 지상부의 건물중이 증가하였다. 또한, 15°C에서 묘의 품질이 우수하였다. 반면, ‘GB’의 생육은 25°C에서 유의적으로 촉진되었고, 품질 또한 우수하였다. 따라서 접목 후 오이 묘의 적정 주야간 온도는 ‘NS’와 ‘SD’는 28/15°C, ‘GB’는 28/25°C인 것으로 판단된다.
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Proper Day and Night Temperatures for Different Cultivars of Cucumber Seedlings after the Grafting Stage
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Research Article
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Collection and Morphological Analysis of Korean Wild Chrysanthemum zawadskii and C. makinoi
수집 야생 구절초 및 마키노 국화의 형태학적 세포학적 분석
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Jeong So, Youn Ok Jung, Hak-Dong Lee, Sanghyun Lee, Jin Hee Lim
소정, 정연옥, 이학동, 이상현, 임진희
- Over the course of seven years, different varieties of Chrysanthemum zawadskii were collected from 30 regions of Korea. All C. zawadskii varieties …
7년에 걸쳐 한국의 30개 지역에 분포하고 있는 다양한 구절초들을 수집하였다. 모든 구절초들은 자생지와 무관하게 흰색 또는 분홍색 설상화 형태로 나타난다. 이와 달리, …
- Over the course of seven years, different varieties of Chrysanthemum zawadskii were collected from 30 regions of Korea. All C. zawadskii varieties exhibit ray flowers that were either white or pink regardless of the collection region. However, they were classified into three groups according to the shape of the leaves, with large differences in the leaf shape (Group 1: C. zawadskii, Group 2: C. zawadskii with a slender leaf, and Group 3: C. zawadskii var. yezoense). A different species of Chrysanthemum called C. makinoi was assigned to Group 4. In terms of location, Group 1 can be found throughout Korea, while Group 2 is found primarily in highlands and confined locations such as Mt. Baekdu, Ulleung Island, and Mt. Halla on Jeju Island. Group 3 is found near the coast and has broad leaves with minimal splits, whereas Group 4 has been identified in Gangwon Province, a limestone location, with a variety of leaf shapes. One region was chosen for each group for an extensive comparison (Group 1: C. zawadskii var. latilobum from Mt. Hwangmae, Group 2: C. zawadskii var. lucidum from Ulleung Island, Group 3: C. zawadskii var. yezoense from Geoje Island, and Group 4: C. makinoi from Jeongseon). When morphological traits were compared by group, C. zawadskii var. lucidum (Group 2) had the widest flower diameter at 60.35 mm. Moreover, C. zawadskii (Group 1) and C. makinoi (Group 4) had the largest leaf length and width at the base, with no significant differences in the chlorophyll content. The cauline leaf of C. zawadskii var. yezoense (Group 3) had the greatest leaf length (38.79 mm), width (37.14 mm), and chlorophyll content (37.13 SPAD). However, the difference was not statistically significant when compared to the basal leaf. Ultimately, the results of this study showed that C. zawadskii var. latilobum (Group 1) and C. zawadskii var. yezoense (Group 3) were hexaploid, C. zawadskii var. lucidum (Group 2) was tetraploid, and C. makinoi (Group 4) was diploid. This research was carried out as part of a standardized procedure aimed at determining resources for use as basic data for Chrysanthemum genome research and functional breeding.
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7년에 걸쳐 한국의 30개 지역에 분포하고 있는 다양한 구절초들을 수집하였다. 모든 구절초들은 자생지와 무관하게 흰색 또는 분홍색 설상화 형태로 나타난다. 이와 달리, 잎 형태는 차이가 크므로 잎의 형태에 따라 3개 그룹으로 분류하였다(Group 1: 구절초, Group 2: 가는잎구절초, Group 3: 남구절초). Group 4는 마키노국화로 구절초와는 다른 국화 종이 분류되었다. 위치적으로 Group 1은 전국적으로 분포되었으며, Group 2는 주로 백두산, 울릉도, 제주도 한라산과 같이 상대적으로 고지대인 제한적인 지역에 서식한다. Group 3은 해안가에서 발견되며 잎이 넓고 갈라짐이 적은 반면, Group 4는 석회암 지대인 강원도에서 서식하며 잎 모양이 다양하다. 비교를 위해 각 group별로 한 지역을 선정하였다(Group 1: 황매산 자생 구절초, Group 2: 울릉국화, Group 3: 거제도 자생 남구절초, Group 4: 정선 자생 마키노국화). Group 별로 형태적 특성을 비교한 결과, 울릉국화(Group 2)의 꽃의 길이가 60.35mm로 가장 길었다. 또한, 구절초(Group 1)와 마키노국화(Group 4)는 기저부 잎 길이와 너비가 가장 길었으며, 엽록소 함량에는 큰 차이가 없었다. 상단부 잎의 경우 남구절초(Group 3)에서 길이(38.79mm), 너비(37.14mm), 엽록소 함량(37.13 SPAD)로 가장 컸다. 그러나 기저부 잎과 비교했을 때, 그 차이는 통계적으로 유의하지는 않았다. 마지막으로, 구절초(Group 1) 및 남구절초(Group 3)는 6배체, 울릉국화(Group 2)는 4배체, 마키노국화(Group 4)는 2배체였다. 본 연구는 국화 유전체 연구 및 기능성 육종을 위한 기초자료로 활용할 수 잇는 자원을 확보하기 위한 표준화 과정의 일환으로 수행되었다.
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Collection and Morphological Analysis of Korean Wild Chrysanthemum zawadskii and C. makinoi
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Research Article
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Characterizing the Metabolic Regulation of Organic Acids in the Fruits of ‘Minihyang’ Mandarin at Different Developmental Stages and on Different Rootstocks
‘미니향’ 만다린 과실에서 생육단계와 대목에 따른 과실 유기산 대사의 조절 특성
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Ha Rim Hong, Eun Ui Oh, Seung Gap Han, Su Hyun Yun, Ho Bang Kim, Kwan Jeong Song
홍하림, 오은의, 한승갑, 윤수현, 김호방, 송관정
- This study was conducted to evaluate the effect of different rootstocks on the organic acid content of ‘Minihyang’ mandarin at different developmental …
‘미니향’ 만다린에서 과실 생육단계에 따른 유기산 함량 변화와 대목에 의한 영향을 평가하고자 본 연구를 수행하였다. ‘미니향’ 과실의 적정산도는 비대 초기에 높았고, 성숙기 …
- This study was conducted to evaluate the effect of different rootstocks on the organic acid content of ‘Minihyang’ mandarin at different developmental stages. The titratable acidity of ‘Minihyang’ fruit was the highest in the early stage and decreased rapidly during maturity. The level of acidity in the Flying Dragon rootstock was significantly higher than that in the trifoliate orange rootstock at the early stage of growth, but the difference between them was insignificant during maturity. The content of organic acid showed a similar trend to that of titratable acidity, but the difference between rootstocks was very small. In the early stages of fruit development of ‘Minihyang’ mandarin, most of the organic acids were citric acid, but during maturation and ripening, malic acid was slightly more than citric acid. Unlike the decrease in citric acid, citrate synthase (CS) activity was maintained at a high level throughout the growing period. On the other hand, with the increase in malic acid, the activities of NAD-malic dehydrogenase (MDH) and NADP-malic enzyme(ME) gradually increased. The expression of CS genes related to citric acid synthesis increased gradually with fruit growth, while the expression of aconitase genes related to decomposition increased gradually. MDH and ME genes related to malic acid and oxalic acid synthesis in mitochondria increased with fruit ripening, while cytoplasmic MDH decreased. In addition, in the expression of phosphoenolpyruvate carboxylase (PEPC), PEPC1 was maintained high throughout the fruit growth period, while PEPC2 showed a gradual increase. The organic acid content and composition of ‘Minihyang’ fruit were regulated by the degree of citric acid synthesis and decomposition and malic acid synthesis. In terms of accumulation of organic acids in vacuole, ATPase genes were expressed at a constant level, while PPase genes were not expressed consistently. The results of this study showed that the organic acid content and composition of ‘Minihyang’ fruit were regulated by the degree of citric acid synthesis and decomposition and malic acid synthesis.
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‘미니향’ 만다린에서 과실 생육단계에 따른 유기산 함량 변화와 대목에 의한 영향을 평가하고자 본 연구를 수행하였다. ‘미니향’ 과실의 적정산도는 비대 초기에 높았고, 성숙기 이후 급격히 감소하여 낮게 유지되었다. 탱자보다 비룡탱자 대목에서 생육 초기에 유의적으로 높은 수준이었으나, 이후 성숙기의 차이는 미미하였다. 유기산의 함량은 적정 산도와 유사한 경향이었으나, 대목 간의 차이는 매우 적은 편이었다. 과실 생육 초기에는 대부분 구연산이었으나, 성숙기 이후는 오히려 사과산이 구연산보다 약간 많은 경향이었다. 구연산의 감소와 달리 citrate synthase(CS) 활성은 생육기 내내 높게 유지되었다. 반면 사과산의 증가와 더불어 NAD-malic dehydrogenase(MDH)와 NADP-malic enzyme(ME)의 활성은 점차 증가하는 경향이었다. 한편 구연산 합성관련 CS 유전자들의 발현은 과실 생육과 더불어 점차 증가하였고, 분해관련 aconitase 유전자들의 발현은 점차 증가하는 경향이었다. 사과산 및 수산 합성관련 미토콘드리아 내 작용 MDH 및 ME 유전자들은 과실 성숙과 더불어 증가하는 경향이었으나, 세포질 작용 MDH는 반대로 감소하는 경향이었다. 또한 phosphoenolpyruvate carboxylase(PEPC)의 발현에서는 PEPC1은 과실 생육기 내내 높게 유지된 반면 PEPC2는 점차 증가하는 경향을 나타냈다. 액포 내 유기산 축적과 관련해서는 ATPase 유전자들은 발현이 일정하게 유지되는 반면, PPase 유전자들의 발현은 일정하지 않았다. 본 연구결과 ‘미니향’ 과실의 유기산 함량 및 조성은 구연산 합성 및 분해와 사과산 합성 정도에 의해 조절되는 것으로 나타났다.
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Characterizing the Metabolic Regulation of Organic Acids in the Fruits of ‘Minihyang’ Mandarin at Different Developmental Stages and on Different Rootstocks