• Journal of Applied Biological Chemistry
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• 제66권
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• pp.388-393
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• 2023

This study evaluated the in vitro nematicidal activity of Glycyrrhiza uralensis root extracts (GuRE) on Meloidogyne incognita eggs and juveniles. The results showed that treatment of M. incognita eggs with 2.0 mg/mL GuRE for 5 and 10 d resulted in 64.0 and 68.1% hatch inhibition, respectively. Furthermore, the relative mortality of J2 was 96.2% after treatment with 2.0 mg/mL GuRE for 48 h. Changes in the shape of the eggs and juveniles were determined after incubation with 2.0 mg/mL GuRE for 5 d and 48 h, respectively. These preliminary results suggest that GuRE can be used as an environment-friendly bio-nematicide to control root-knot nematodes. In the future, in vivo assays should be conducted using GuRE to ascertain its potential for widespread application as a nematicide.

• The Plant Pathology Journal
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• 제35권6호
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• pp.654-661
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• 2019

The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea's soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R² = 0.996, slope = -3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set.

• 식물병연구
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• 제11권2호
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• pp.167-172
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• 2005

오이 흰가루병균의 생물적 방제제로 선발한 중복기생균 Ampelomyces quisqualis 94013의 오이 흰가루병 균에 대한 기생력을 온도와 습도에 대하여, 그리고 mineral oil 등 10종의 전착제와 혼용하였을 때 기생력 증진효과를 검토하였다. 또한 A. quisqualis 94013균주의 기주범위에 대하여 오이, 호박, 참외, 멜론, 수박, 박, 딸기, 가지, 토마토, 콩, 팥, 장미에 기생하는 흰가루병균 Sphaerotheca속 6종, Erysiphe속 1종에 대하여 조사하였다. 오이 흰가루병균에 대하여 A. quisqualis 94013의 기생이 가능한 온도 범위는 $12\~30^{\circ}C$이고, 기생 최적온도는 $20\~28^{\circ}C$이였다. A. quisqualis 94013균주는 $20\~35\%$의 저습도에서 오이흰가루병균에 대하여 기생력이 저조하였다. 또한, A. quisqualis 94013의 기주범위조사에서 오이, 멜론, 수박, 참외, 박, 딸기, 토마토, 가지, 장미 등 12종의 작물을 침해하는 흰가루병균 Sphaerotheca속 6종, Erysiphe속 1종에 대하여 기생성이 있어 기주특이성이 없는 것으로 나타났다.

• The Plant Pathology Journal
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• 제32권4호
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• pp.329-339
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• 2016

The short-term effects of low-level contamination by heavy metals (As, Cd, Cu, and Pb) on the soil health were examined by analyzing soil nematode community in soils planted with tomatoes. For this, the soils were irrigated with five metal concentrations ([1, 1/4, $1/4^2$, $1/4^3$, and 0] ${\times}$ maximum concentrations [MC] detected in irrigation waters near abandoned mine sites) for 18 weeks. Heavy metal concentrations were significantly increased in soils irrigated with MC of heavy metals, among which As and Cu exceeded the maximum heavy metal residue contents of soil approved in Korea. In no heavy metal treatment controls, nematode abundances for all trophic groups (except omnivorous-predatory nematodes [OP]) and colonizer-persister (cp) values (except cp-4-5) were significantly increased, and all maturity indices (except maturity index [MI] of plant-parasitic nematodes) and structure index (SI) were significantly decreased, suggesting the soil environments might have been disturbed during 18 weeks of tomato growth. There were no concentration-dependent significant decreases in richness, abundance, or MI for most heavy metals; however, their significant decreases occurred in abundance and richness of OP and cp-4, MI2-5 (excluding cp-1) and SI, indicating disturbed soil ecosystems, at the higher concentrations (MC and MC/4) of Pb that had the most significant negative correlation coefficients for heavy metal concentrations and nematode community among the heavy metals. Therefore, the short-term effects of low-level heavy metal contamination on soil health can be analyzed by nematode community structures before the appearance of plant damages caused by the abiotic agents, heavy metals.

• 한국약용작물학회지
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• 제11권2호
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• pp.122-126
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• 2003

겨우살이 기생위치는 숙주목(상수리나무 등)의 종류에 관계없이 대부분 지면에서 5-10m높이의 일사량이 많은 상단부에 기생하였다. 줄기의 분화는 주경에서 2개씩 연속분지를 형성하였고, 잎은 정단줄기의 상단부에 2매씩 대생하였으며, 종실은 연황색의 7-8mm 크기의 장과였다. 겨우살이 화아분화는 초기 둥근 돔형의 화아정단이 형성되고 엽원기가 1, 2매 차례로 분화한 다음 심장형으로 발달하며 악편이 발생하였는데, 중앙부에서 먼저 진행되었고 이어 양측 면에 2개를 형성하였다. 잎은 이면의 표피 2-3층 아래에 기공과 공변세포가 관찰되었고, 겨우살이는 기주목의 흡착부에서 기주조직의 코르크층을 통과하여 목질부에 뿌리를 내리고 여러 갈래로 분지하여 생장하는 것을 확인하였다.

• 식물분류학회지
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• 제33권4호
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• pp.411-420
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• 2003

한국산 열당과의 종자형태를 조사하기 위하여 5속 5종 1 변종과 히말라야의 Boschniakia himalaica Hook. f. & Thomson in Hook. f.(총 7 분류군)의 종자를 주사전자현미경을 이용하여 관찰하였다. 한국산 열당과는 종자 크기, 종피의 구조, 과실 당 종자의 수에 따라 두 가지 유형이 구별 되었다. - Type I: 크기가 1mm 미만, 종피 구조는 망상, 과실 당 종자의 개수는 약 1,000개 이상. Type I은 외종피의 내부 표면 무늬에 따라 세 가지 하위구분으로 나뒤어 질 수 있다; (1) Subtype Ia: 망상 -불규칙한 줄무늬형(Ia')과 깊은 망상(Ia")을 포함한다. (2) Subtype Ib: 유공상, (3) Subtype Ic: 평활상. Type II: 크기가 1mm 이상, 종피구조는 불규칙하게 돌출된 모양(creasted), 과실 당 종자의 개수는 약 1,000개 미만(Lathraea japonica Miq.). 한국산 열당과에 대한 종자 형질의 분류학적 적용에 관하여 간략하게 검토하였다.

• Journal of Microbiology and Biotechnology
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• 제34권8호
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• pp.1627-1635
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• 2024

The inhabitation and parasitism of root-knot nematodes (RKNs) can be difficult to control, as its symptoms can be easily confused with other plant diseases; hence, identifying and controlling the occurrence of RKNs in plants remains an ongoing challenge. Moreover, there are only a few biological agents for controlling these harmful nematodes. In this study, Xenorhabdus sp. SCG isolated from entomopathogenic nematodes of genus Steinernema was evaluated for nematicidal effects under in vitro and greenhouse conditions. The cell-free filtrates of strain SCG showed nematicidal activity against Meloidogyne species J2s, with mortalities of > 88% at a final concentration of 10%, as well as significant nematicidal activity against the three other genera of plant-parasitic nematodes in a dose-dependent manner. Thymine was isolated as active compounds by assay-guided fractionation and showed high nematicidal activity against M. incognita. Greenhouse experiments suggested that cell-free filtrates of strain SCG efficiently controlled the nematode population in M. incognita-infested tomatoes (Solanum lycopersicum L., cv. Rutgers). In addition, a significant increase in host plant growth was observed after 45 days of treatment. To our knowledge, this is the first to demonstrate the nematicidal activity spectrum of isolated Xenorhabdus species and their application to S. lycopersicum L., cv. Rutgers under greenhouse conditions. Xenorhabdus sp. SCG could be a promising biological nematicidal agent with plant growth-enhancing properties.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.37-43
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• 2008

The durability test of turbo-blower for PEM fuel cell is very important process of BOP development. It is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the air supply system to increase the reliability and to reduce the lifetime cost. In this study, turbo-blower supported by oil-free bearing is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. The impeller of blower was adopted mixed type of centrifugal and axial. So, it has several advantages for variable operating condition. The turbo-blower test results show maximum parasitic power levels below 1.67kW with the 30,000 rpm rotating speed, the flow rate of air has maximum 163SCFM(@PR1.1). For proper application of FCV, these have to durability test. This paper describes the experiment for confirming endurance and stability of the turbo-blower for 500 hours.

• 한국균학회지
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• 제29권2호
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• pp.116-122
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• 2001

흰가루병에 대하여 생물적 방제제로 선발된 Ampelomyces quisqualis94013(AQ94013)의 포자현탁액을 처리하여 오이 흰가루병균(Sphaerotheca fuliginea)에 대한 침입과정을 전자현미경과 광학현미경으로 관찰한 결과, 포자현탁액 처리 후 4시간 만에 포자가 흰가루병균의 분생포자, 분생자경 및 균사위에서 발아하고, 17시간 후에는 유사부착기가 형성되어 흰가루병균의 균사에 부착되었다. 24시간 후에는 균사내에 침입하였으며, 44시간 후에는 흰가루병균의 균사와 분생자경의 하부에 AQ94013의 병자각이 형성되기 시작했다. 48시간 후에는 병자각이 성숙되었으며, 52시간 후에는 병자각의 공구에서 병포자가 분출되고, 흰가루병균의 균사 및 분생자경은 변형되어 죽었다. 한편, 오이흰가루병균에 대하여 A. quisqualis 94013의 배양여액을 농축하여 처리한 결과에서 물처리와 차이가 없었으므로 흰가루병균에 대한 감염기작은 A. quisqualis 94013가 독소생성에 의한 것이 아니라 직접기생에 의하여 흰가루병균을 죽이는 것으로 판단된다.

• 한국균학회지
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• 제27권5호
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• pp.345-348
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• 1999

외생균근성 버섯인 송이는 동북아시아지역에서 가장 비싼 버섯이다. 이 버섯은 식용버섯이므로 자실체 표면에 병원균이 발생한다면 매우 심각한 문제가 아닐 수 없다. 송이 자실체의 기생균을 발견하였으므로 이에 대하여 자세히 설명하고 Syzygites megalocarpus Ehrenberg ex Fries로 동정하고 이분지털곰팡이로 명명하였음을 보고한다.