• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.55-55
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• 2015

Rust is one of the most destructive diseases on economically important plants such as agricultural and horticultural crops, as well as forest trees [1]. Chemical treatment is the most effective means to control rust, but use of the chemical fungicides involves inevitable risks to human health and environment [2]. Unfortunately, biocontrol is currently impracticable for rust disease management [3]. It is necessary to exploit biocontrol agents to help prevent rust diseases. As a fundamental research for future development of biocontrol agents for rusts, biodiversity of hyperparasites occurring on rust fungi was investigated. During 2006-2010, 197 fungal isolates of the rust hyperparasites were collected and isolated from various combinations of mycohosts and plant hosts in many regions of Korea. Based on morphological and molecular data, they were identified as 8 genera and 12 species. Besides, phylogenetic relationships between the hyperparasites and related taxa were inferred. A total of 114 isolates of Pseudovirgaria were obtained from rust pustules of Phragmidium spp. and Pucciniastrum agrimoniae infecting rosaceous plants. Phylogenetic analysis using multigene sequences revealed a high level of genetic variability among many isolates of Pseudovirgaria and close correlation between the isolates and mycohosts. Only two species of Pseudovirgaria, P. hyperparasitica and P. grisea are often difficult to distinguish by their morphological similarity, but on the molecular basis they were clearly differentiated from each other. There had been no previous record of P. grisea outside Europe, but the present study has proved its presence in Korea. Among six distinct groups (five of P. hyperparasitica and one of P. grisea) within the Pseudovirgaria isolates, each lineage of P. hyperparasitica was closely associated with specific mycohosts and thus might have cospeciated with their mycohosts, which probably led to coevolution. Although P. grisea possesses a host preference for Phragmidium species occurring on Rubus, it was not specific for a mycohost. P. grisea seems to evolve in the direction of having a broad mycohost range. Seventeen isolates of Verticillium-like fungi were isolated from rust sori. Based on morphological data and DNA sequence analysis, the isolates were identified as three Lecanicillium species, viz. L. attenuatum, Lecanicillium sp. 1, Lecanicillium sp. 2, and V. epiphytum. The unidenified two species of Lecanicillium appear to be previously unknown taxa. Sixty-six isolates of miscellaneous hyphomycetes belonging to 6 species of 5 genera were obtained from pustules of rust fungi. On the basis of morphological and molecular analyses, the miscellaneous hyphomycetes growing on rusts were identified as Acrodontium crateriforme, Cladophialophora pucciniophila, Cladosporium cladosporioides, Phacellium vossianum, Ramularia coleosporii, and R. uredinicola.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.734-742
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• 2012

To compare RNA interference-mediated gene silencing technique and T-DNA integration for gene function analysis in Chinese cabbage, BrSAMS-knockout (KO) line and BrSAMS-knockdown (KD) line were used. The KO line had lost the function of a Brassica rapa S-adenosylmethionine synthetase (BrSAMS) gene by T-DNA insertion and the KD line had shown down-regulated BrSAMS genes' expression by dsRNA cleavage. From microarray results of the KO and KD lines, genes linked to SAMS such as sterol, sucrose, homogalacturonan biosynthesis and glutaredoxin-related protein, serine/threonine protein kinase, and gibberellin-responsive protein showed distinct differences in their expression levels. Even though one BrSAMS gene in the KO line was broken by T-DNA insertion, gene expression pattern of that line did not show remarkable differences compared to wild type control. However, the KD line obtained by RNAi technique showed prominent difference in its gene expression. Besides, change of polyamine and ethylene synthesis genes directly associated with BrSAMS was displayed much more in the KD line. In the microarray analysis of the KO line, BrSAMS function could not be clearly defined because of BrSAMS redundancy due to the genome triplication events in Brassicaceae. In conclusion, we supposed that gene knock-down method by RNAi silencing is more effective than knock-out method by T-DNA insertion for gene function analysis of polyploidy crops such as Chinese cabbage.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.151-156
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• 2016

Medicinal plants resources are becoming important assets since their usages have been expanded to the development of functional foods for human health, natural cosmetics, and pharmaceutical industries. However, names are different from each country and their phylogenetic origins are not clear. These lead consumers to be confused. In particular, when they are morphologically similar and distributed as dried roots, it is extremely difficult to differentiate their origins even by specialists. Recently, molecular markers have been extensively applied to identify the origin of many crops. In this review, we tried to overview the current research achievements for the development of suitable 'origin identification' regarding to the differentiation of Angelica species. Furthermore, more advanced techniques including amplification genome based marker analyses are also discussed for their practical applications in the authentication of particular medicinal plant in Angelica species.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.163-167
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• 2014

The average temperatures for year and winter season have been risen by $0.7{\circ}C$ and $1.4{\circ}C$, respectively, during the last 30 years. Recently abnormal climate phenomena occurred frequently results in severe loss of vegetable crops grown in Korea. Specially, Chinese cabbages grown in the southern area of Korea are often significantly affected by sudden cold waves during winter season before harvest. This experiment was conducted to find out a potential role of covering materials on the protection of frost damage of 'Bularm' chinese cabbage in the winter season. The lowest temperature was $-15.8^{\circ}C$ in non-covering, $-8.1^{\circ}C$ in the PE film covering and $-4.6^{\circ}C$ in the non-woven fabric covering with PE film, respectively. The cumulative times below $4.0^{\circ}C$ were 145.5 hours for the non-covering treatment, 94 hours in the PE film covering and 14.5 hours in the non-woven fabric covering with PE film, respectively. The symptoms of frost damage were severe at non-covering chinese cabbages compared to polyethylene film (PE) non-woven fabric with PE covering ones. Microscopic studies showed the normal anatomical structure of palisade and spongy tissue of cabbage leaves covered with non-woven fabric with PE film. Leaf cells, however, were slightly damaged in cabbages covered with PE film alone, and both palisade and spongy cells were were completely collapsed in uncovered cabbages. The result of this study suggests that chinese cabbages is required to be covered with non-woven fabric with PE film to minimize the frost damage by sudden cold wave below $-7^{\circ}C$.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.312-316
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• 2012

This study evaluated the effect of polyolefine greenhouse covering film on growth of lettuce and cucumber. The growth of lettuce and cucumber plants under conventional film (polyethylene plus ethylenevinyl acetate, PE + EVA) and polyolefine (PO) film were evaluated in a greenhouse. The physical qualities of PO film, such as tensile strength and tear strength, were stronger than conventional PE + EVA film. PO film showed 4% higher transmission performance in photosynthetic active radiation (PAR) than PE + EVA film. The average day and night temperature in greenhouse under PO film were $1.5^{\circ}C$ and $0.8^{\circ}C$ higher but there was no significant difference in relative humidity compared with conventional film. Chlorophyll content of lettuce and cucumber plants grown under PO film were higher than conventional film. Growth characteristics; plant height, leaf area, fresh weight and dry weight of cucumber was shown better for PO film. The yields of cucumber and lettuce was increased 14.0% and 13.6% respectively, when the crops were grown under PO covering film greenhouse.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.54-54
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• 2019

Apple (Malus domestica) is one of the most economically important fruits in Korea. But virus infection has decreased sustainable production of apple and caused the serious problems such as yield loss and poor fruit quality. Virus or viroid infection including Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple mosaic virus (ApMV) and Apple scar skin viroid (ASSVd) has been also reported in Korea. In many cases, apple is infected with virus and viroid with no specific symptoms, the damage caused by the virus are unaware significantly. In our research, we tried to eliminate viruses in the rootstock for the disease-free seedlings of the apple dwarfing rootstock M.9 and M.26. The method of virus elimination was meristem culture, heat($37^{\circ}C$, 6weeks) treatment and chemistry($Ribavirin^{(R)}$) treatment. The analytical methods commonly used for the detection of virus is Enzyme-linked Immuno-Sorbent Assay(ELlSA) and Reverse Transcription-polymerase Chain Reaction(RT-PCR). RT-PCR method was more 30% sensitive than ELISA method. Efficiency of method eliminate virus appeared meristem method > heat treatment > chemistry treatment. The higher acquisition rate of disease-free seedlings is 30~40% on meristem treatment. In meristem treatment, the apple dwarfing rootstock M.9 gained infection ratio of ACLSV, ASPV and ASGV were 45%, 60% and 50% respectively. In the apple dwarfing rootstock M.26, infection ratio of ACLSV, ASPV and ASGV were 40%, 55%, 55%, respectively. Based on our results, it was found that most effective method of disease-free seedlings apple dwarfing rootstocks was by meristem treatment than heat method and chemistry treatment.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.263-269
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• 2021

Growth and fruit characteristics of 'Duke' highbush blueberry by mixture of different organic matters in soil were investigated. The soil acidity was 4.2 to 4.8, sawdust treatment was the highest, and peat soil and peatmoss treatments were similar. The organic matter content of the soil was 2.5% for sawdust and 4.1% for soil with peatmoss and peat soil. The soil hardness of all treatment was found to be about 1 ~ 5 kgf cm^-2 which was suitable for growing crops. The number of suckers and main stems were high in the order of peat soil, peatmoss, sawdust treatment. In addition, the blueberry plants in the peatmoss and peat soil treatments had thicker and longer suckers and more shoots than those in the sawdust treatment. Among the characteristics of fruit, there was no statistical difference between the organic materials treatment in weight, diameter, length, and hardness of fruit. However, the total soluble solid and fruit yield were high in the order of peat soil, peatmoss, sawdust treatment. Therefore, as a result of comprehensively reviewing the characteristics of growth and fruits according to the soil environment, it was determined that peatmoss could be replaced with peat soil for stable production in domestic blueberry cultivation.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.52-59
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• 2022

Pest control treatment was carried out using an unmanned automatic pesticide spraying system that can spray pesticides on crops while moving autonomously to control pests in vegetable greenhouse. As a result of examining the control effect on tomato and strawberry on thrips (Frankliniella occidentalis) and greenhouse whitefly (Trialeurodes vaporariorum) pests, 85.6% of yellow flower thrips were found in tomatoes and 87.5% in strawberries, and 81.7% (tomato) and 80.6% (strawberry) of greenhouse whitefly. In addition, the control effect according to the pesticide treatment method showed a control effect of 81.7% of the chemical spraying treatment by manpower and 83.9% of the automatic moving pesticide spraying treatment (F=22.1, p < 0.001). When comparing the control effect between the two treatment sections, there was no significance, but the automatic transfer spraying treatment showed a 2.2% higher effect. On the other hand, as a result of comparing the spraying time of the drug, the automatic unmanned control sprayer had a spraying time of 5 min/10a, which took about 25 min less than the conventional manpower spraying time of 25-30 min/10a. Based on these results, it was judged that the automatic transfer spraying method could be usefully used for efficient pest control in the facility greenhouse during the peak period of development.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.578-586
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• 2016

In this study, we evaluated the effects of soil incorporation of crotalaria as a green manure on the growth and yields of 'Seolhyang' strawberry and inorganic soil nitrogen levels in a greenhouse. Four different N treatments were used, as follows: zero N fertilizer (control), crotalaria, crotalaria with 50% urea, and 100% urea. The recommended N requirement (100% urea) for strawberry was $86kgN{\cdot}ha^{-1}$ and 50% of the recommended N (50% urea) was $43kgN{\cdot}ha^{-1}$. Crotalaria was sowed on June $17^{th}$, 2011 and cultivated for 37 days. The amount of N supply from soil incorporation of crotalaria was $104kgN{\cdot}ha^{-1}$. Strawberry was planted on September $9^{th}$, 2011 and cultivated for 255 days after planting. The concentrations of soluble solids and acidity of strawberry fruits for the crotalaria treatment were higher than for the crotalaria with 50% urea and 100% urea treatments. On the other hand, the growth and yield of strawberry was the highest for the crotalaria with 50% urea and 100% urea treatments, followed by the crotalaria treatment, and the lowest for the control. Soil inorganic N concentration for the crotalaria treatment was continuously decreased to $24mg{\cdot}kg^{-1}$ at the end of the growing season, while crotalaria with 50% urea and 100% urea treatments maintained an inorganic N concentration that ranged from 35 to $50mg{\cdot}kg^{-1}$. These results indicate that the amount of N supply from soil incorporation of crotalaria may not be enough because strawberry yield was lower than for other N treatments. Therefore, additional nitrogen, such as 50% urea after soil incorporation of crotalaria, is recommended.

• Near Infrared Analysis
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• v.1 no.1
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• pp.23-26
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• 2000

The objectives of this study were to examine the ability to predict soluble solid and firmness in intact apple based on the visible/near-infrared spectroscopic technique. Two cultivars of apples, Delicious and Gala, were handled, tested and analyzed. Reflectance spectra, Magness-Taylor (MT) Firmness, and soluble solids in apples were measured sequentially. Maximum and minimum diameters, height, and weight of apples were recorded before the MT firmness tests. Apple samples were divided in to a calibration set and a validation set. The method of partial least squares (PLS) analysis was used. a unique set of PLS loading vectors (factors) was development for soluble solid and firmness. The PLS model showed good relationship between predicted and measured soluble solids in intact apples in the wavelength range of 860∼1078 nm. However, the PLS analysis was not good enough to predict the apple firmness.