• The Plant Pathology Journal
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• 제35권6호
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• 한국수산과학회지
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• 제43권6호
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• pp.687-692
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• 2010

The mass cultivation of Ecklonia cava Kjellman was studied as a potential biomass source for the extract industry in Korea. Experiments were conducted to investigate the optimal conditions for artificial seed production and mass cultivation of this species. Maximum growth and young thalli development in the nursery culture area occurred at 2 m depth, whereas maximum growth of thalli in the main culture area occurred at 1 m depth. Production of E. cava was between 2.6 and 3.6 kg wet wt. $m^{-1}$ after depth control and removal of fouling organism, etc. The relationship between optimal water depth for culture and underwater irradiance during the E. cava cultivation was calculated as: y = -0.718x + 8.042 ($r^2$=0.976). The growth rates achieved in this trial indicate that E. cava cultures could produce and supply sufficient biomass.

• The Plant Pathology Journal
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• 제36권1호
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• pp.67-75
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• 2020

Tomato spotted wilt virus (TSWV) is one of the plant viruses transmitted by thrips and causes severe economic damage to various crops. From 2008 to 2011, to identify natural host species of TSWV in South Korea, weeds and crops were collected from 5 regions (Seosan, Yesan, Yeonggwang, Naju, and Suncheon) where TSWV occurred and were identified as 1,104 samples that belong to 144 species from 40 families. According to reverse transcription-polymerase chain reaction, TSWV was detected from 73 samples from 23 crop species, 5 of which belonged to family Solanaceae. Additionally, 42 weed species were confirmed as natural hosts of TSWV with three different life cycles, indicating that these weed species could play an important role as virus reservoirs during no cultivation periods of crops. This study provides up-to-date comprehensive information for TSWV natural hosts in South Korea.

• Journal of Forest and Environmental Science
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• 제19권1호
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• pp.48-68
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• 2003

현재 분재재배의 큰 문제점은 높은 노동력에 비해 생산성이 매우 낮은 것이다 본 연구는 관수시스템과 관리방법의 개발로 고품질의 분재를 대량생산하기 위해 실시되었다. FRP분상에서 재배된 분재는 직수관수나 스프링클러 관수에 비해 저변관수시스템에서 생육이 매우 좋았다. 또한 저면관수시스템은 노동력을 크게 줄일 수 있었고 짧은 기간에 대량생산을 할 수 있었다. 또한 비닐하우스내(內)에서 저면관수 시스템의 이용은 조기생산은 물론 고품질의 분재를 생산할 수 있었으며 내한성이 약한 수종들도 겨울재배가 가능하였다. 본 연구는 세계시장을 위한 국가경쟁력에 크게 기여하였을 뿐만 아니라 농가 수익에도 큰 도움을 줄 수 있었다.

• 농촌계획
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• 제18권3호
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• pp.149-164
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• 2012

The purpose of the present study is to construct a rural development strategy from the nexus between spatial changes in specialized crops and suitable cultivation area of the crops. This paper pays particular attention to identify product life cycle of specialized crops in rural areas and estimate the impact of climate change on alterations in spatial distribution of the crops. In order to do so, first of all, this study applies multi-level model (Random coefficient model) to estimate the regional coefficient of five orchard crops. It utilizes the data 1995 to 2010 Korea Agricultural Census. Futhermore, it also adopts overlay analysis by ArcGIS to identify the development path of the crops and the relationship with climate change. Based on the results, it suggests a mechanism activating regional agriculture. The findings propose re-searching and relocating specialized regions of the crops. Especially, it proves each rural area can drive the new agricultural strategy to strengthen regional agriculture by estimating the relationship between development of specialized crops and suitable cultivation areas. For instance, shifting specialized crops in particular regions and enriching genetic or species varieties can be primary measures and it will contribute to improve the reliable base for income sources in the rural communities. This paper also offers specific policy implications regarding rural development plans in response to crops' life cycle and climate changes.

• 한국산림과학회지
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• 제89권5호
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• pp.591-597
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• 2000

본 실험은 층층나무(Cornus controversa Hemsl)와 말채나무(Cornus walteri Wanger)의 양묘시 적정 차광율을 구명하고자 상대광도가 100%(대조구), 50%, 30%, 10% 및 2%로 조절된 피음포지에서 실시하였다. 두 수종의 수고생장은 상대광도 50%에서 가장 높은 생장을 보였고, 근원경생장은 대조구와 50%구에서 서로 비슷하게 높은 생장을 기록하였다. 물질생산량을 보면 층층나무의 전체 생산량의 경우 50%에서 자연전광의 대조구보다 높은 생산량을 보였으나 지하부의 생산량은 다소 낮았다. 말채나무는 50%에서 전체 생산량은 대조구보다 낮았으나 지상부 생산량은 다소 높은 생산량을 보였다. 30%이하의 상대광도에서는 수고생장, 근원경생장 및 물질생산량이 급격히 감소하였다. 두 수종 모두 30%에서 가장 높은 T/R율을 기록하였으며 전체적으로 말채나무의 T/R율이 층층나무의 T/R율 보다 높았다. 잎의 엽록소 a와 b 및 전체엽록소 함량은 상대광도가 낮을수록 높아지는 경향을 나타내었다.

• Journal of Ginseng Research
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• 제43권1호
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• pp.1-9
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• 2019

Background: Korean ginseng is an important cash crop in Asian countries. However, plant yield is reduced by pathogens. Among the Ilyonectria radicicola-species complex, I. mors-panacis is responsible for root-rot and replant failure of ginseng in Asia. The development of new methods to reveal the existence of the pathogen before cultivation is started is essential. Therefore, a quantitative real-time polymerase chain reaction method was developed to detect and quantify the pathogen in ginseng soils. Methods: In this study, a species-specific histone H3 primer set was developed for the quantification of I. mors-panacis. The primer set was used on DNA from other microbes to evaluate its sensitivity and selectivity for I. mors-panacis DNA. Sterilized soil samples artificially infected with the pathogen at different concentrations were used to evaluate the ability of the primer set to detect the pathogen population in the soil DNA. Finally, the pathogen was quantified in many natural soil samples. Results: The designed primer set was found to be sensitive and selective for I. mors-panacis DNA. In artificially infected sterilized soil samples, using quantitative real-time polymerase chain reaction the estimated amount of template was positively correlated with the pathogen concentration in soil samples ($R^2=0.95$), disease severity index ($R^2=0.99$), and colony-forming units ($R^2=0.87$). In natural soils, the pathogen was recorded in most fields producing bad yields at a range of $5.82{\pm}2.35pg/g$ to $892.34{\pm}103.70pg/g$ of soil. Conclusion: According to these results, the proposed primer set is applicable for estimating soil quality before ginseng cultivation. This will contribute to disease management and crop protection in the future.

• 식물병연구
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• 제23권3호
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• pp.278-282
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• 2017

옥수수는 세계에서 가장 많이 재배되는 곡물 중 하나이며 중요한 식량자원이다. 생산 된 옥수수는 수확 및 건조 후에 저장되는데 저장 옥수수의 질을 떨어뜨리는 곰팡이 감염 및 곰팡이 독소는 생육 시기부터 저장기간 내내 발생한다. 이 연구는 우리나라에서 2015년 수확하여 1년정도 저장한 옥수수를 대상으로 옥수수의 크기와 변색 정도에 따른 감염 곰팡이 종과 독소검출을 조사하였다. 데옥시니발레놀과 제랄레논이 아플라톡신, 오크라톡신, 푸모니신, 티투독소보다 상대적으로 높은 수준으로 검출되었는데 특히, 데옥시니발레놀 경우 작은 낱알에서 $1200{\pm}610{\mu}g/kg$로 검출되었는데, 이는 이보다 큰 낱알에서 검출된 독소 함량에 비해 4배에서 6배까지 많은 양이 검출되었으며, 변색된 낱알의 혼입으로 인해 데옥시니발레놀, 제랄레논 및 푸모니신의 함량이 증가하였다. 곰팡이의 경우 Fusarium, Aspergillus 그리고 Penicillium 속 등 총 10종이 분리되었다. 이중 F. graminearum은 정상적인 낱알에 비해 변색 된 붉은색 낱알과 갈색 낱알에서 60%와 40%로 높은 빈도로 검출되었다. 따라서 수확 후 변색 또는 손상된 옥수수 낱알이 정상 낱알에 섞여 보관될 경우, 손상된 낱알에 오염되어 있던 병원균이 정상 낱알을 감염하여 진균 독소의 발생이 증가할 수 있으므로 오염 낱알의 제거가 곰팡이 및 독소의 오염 예방에 도움이 될 것이다.

• Weed & Turfgrass Science
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• 제7권1호
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• pp.22-34
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• 2018

Miscanthus has been considered as the most promising bioenergy crop for lignocellulosic biomass production. In Korea, M. sacchariflorus and M. sinensis can be found easily in all regions. It is a great advantage to utilize as important species with respect to genetic and cross-breeding programs materials for creation of novel hybrids. For successful breeding programs, it is important to precisely understand the variability of morphological and growth characteristics among Miscanthus species as breeding parent materials. In this study, morphological and growth characteristics were observed in 960 germplasms of two Miscanthus species (M. sacchariflorus and M. sinensis) for growing seasons over three years. Due to the inherent characteristics of these species, the germplasm of M. sacchariflorus among the collected germplasm were reduced in plant height than in the collection area. In M. sinensis, the plant height of germplasm collected mainly from Jeju-do increased more than those collected from collection area. Sixty-one of the collected 960 germplasms were selected and investigated to the morphological characteristics. Based on the investigated morphological data, the phylogenic tree was developed. As the results, it was confirmed that there exist germplasm in which the characteristics of M. sacchariflorus and M. sinensis are mixed. This study of Miscanthus may provide an important information in order to expedite the introduction as breeding materials for creation of new hybrid.

• Mycobiology
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• 제32권3호
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• pp.123-127
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• 2004

Sweet persimmons have been increasingly cultivated in the southern part of Korea. However, anthracnose disease caused by Colletotrichum species is one of the major hindrances in cultivation and productions. In this study, we used polymerase chain reaction(PCR) to detect Colletotrichum species with the AFLP(amplified fragment length polymorphism) method. In AFLP, we used E3(5'-GACTGCGTACCAATTCTA-3') and M1(5'-GATGAGTCCTGAGTAACAG-3') primer combination and, as a result, 262 bp segment was observed in Colletotrichum species only. Specific PCR primers were designed from the sequence data and used to detect the presence of the fungus in genomic DNA isolated from symptomless sweet persimmon plants. Based on sequence data for specific segments, Co.B1(5'-GAGAGAGTAGAATTGCGCTG-3') and Co.B2(5'-CTACCATTCTTCTA GGTGGG-3') were designed to detect Colletotrichum species. The 220 bp segment was observed in Colletotrichum species only, but not in other fungal and bacterial isolates.