• Journal of Ginseng Research
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• 제7권1호
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• pp.37-43
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• 1983

Effect of root-knot nematode (Meloidigyne sp.) 1 infection on the growth and quantity of the inorganic substances in 6 year-old ginseng (Panax ginseng C.A. Meyer) was investigated. Naturally infected 6 year-old ginseng roots were grouped into 3 such as healthy, moderate, and heavy according to the degree of the nematode infection. The roots were sampled in the middle of October, 1980 for chemical analysis. Growth of roots in terms of fresh weight, dry weight, length and diameter was greatly reduced by the nematode infection. The content of inorganic substances was different among the various parts of ginseng roots and according to gall index. Phosphorous and nitrogen contents of the healthy ginseng roots were tend to higher than those of the infected ones, whereas calcium was high in infected roots in the order of heavy, moderate, and healthy. Content of the other inorganic substances was highest in the moderately infected roots, and lowest in the heavy one.

• The Plant Pathology Journal
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• 제15권1호
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• pp.1-7
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• 1999

The production of soybean cyst nematode (SCN), Heterodera glycines, including female formation and fecundity was much higher in SCN race 14 (R14) than in race 3 (R3) in susceptible soybean cultivars Bragg (intolerant), Lee74 (moderately tolerant), and PI 97100 (highly tolerant). The nematode body was also significantly larger in R14 than in R3 at 20 days after inoculation, but the further nematode growth appeared to be slower in R14 than in R3, resulting in no significant difference between the two races at 30 days after inoculation. Within each race, no significant difference was observed in the growth and reproduction among the soybean cultivars tested. Syncytial areas near the nematode lip regions (infection sites) were measured for each soybean cultivar-SCN race combination. R14 induced significantly larger syncytia than R3. Bragg had relatively larger syncytia than Lee74 and PI 97100, but the difference among the soybean cultivars was minimal or not significantly different. Syncytium occupation in the stelar region differed only between PI 97100 and the other two cultivars, which may be somewhat, but not exactly, related to tolerance levels. Syncytial cytomplasm was degenerated more with R14 and in Bragg than with R3 and in Lee74 and PI 97100, respectively. In light microscopy, degenerated syncytia were characterized by depleted and loose cytoplasm with less plastids than normal-looking (intact) syncytia which had dense syncytial cytoplasm. Electron microscopy revealed that degenerated syncytia contained highly vacuolated cytoplasm with degenerated plastids. The above results suggest that structural characteristics of syncytia may match the nematode growth and reproduction.

• The Plant Pathology Journal
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• 제26권2호
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• pp.154-158
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• 2010

Early nematode development and subcellular responses in resistant soybean lines PI 88788 and PI 437654 infected with races 3 (R3) and 14 (R14) of soybean cyst nematode (SCN), Heterodera glycines Ichinohe, were compared. SCN R14 nematodes penetrated and developed significantly more than R3 at 5-6 days after inoculation. Both races also penetrated and developed more in PI 88788 than in PI 437654. Syncytia, characterized by cell wall dissolution and cellular hypertrophy, were developed more in PI 88788 than in PI 437654 and more by R14 than R3, for which less necrotic responses occurred in the former than the latter. This suggests that the latter two may be more resistant and less virulent than the former two, respectively. A common structural feature found in each of PI 437654 and PI 88788 in relation to SCN-resistance was the formation of prominent cell wall appositions and nuclear degeneration prior to cytoplasmic degradation in syncytial cells, respectively. Necrosis and cell wall apposition are types of hypersensitive responses occurring at early stages of the nematode infection so that these structural modifications indicate the inhibition of initial syncytial development related to the early nematode development. As soybean cultivars and lines with identical or similar genotypes have the same types of structural features related to SCN-resistance, the structural modifications induced by SCN infection may result from the expression of inheritable resistance genes, of which the information can be used for breeding soybean cultivars and lines specifically resistant to SCN races.

• The Plant Pathology Journal
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• 제27권3호
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• pp.266-271
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• 2011

Physicochemical characteristics and heavy metal content of soils located along the drainage way of an abandoned mine at Busan, Korea ($35^{\circ}31'N$, $129^{\circ}22'E$) (contaminated soil; CS) and uncontaminated soils (50-70 m apart from the drainage way) (NS) were examined. Growth of tomato plants (Solanum lycopersicom cv. Rutgers) in CS and NS, development of the root-knot nematode (Meloidogyne incognita) as root-knot gall formation on tomato plants, and non-parasitic nematode populations in soil were also examined. Growth of tomato plants, root-knot gall formation, and non-parasitic nematode populations were significantly reduced in CS with higher As content, lower pH, higher electrical conductivity (EC), and lower available phosphate (av. $P_2O_5$) than in NS. None of the other physicochemical characters examined differed significantly between CS and NS (low and no significance) and were above or below the critical levels detrimental to plant growth and nematode development, suggesting that As may be the primary hazardous heavy metal in CS. The toxicity of As might be enhanced at low pH in CS because exchangeable forms of some heavy metals increase with the decrease of soil pH. The heavy metals, especially As, may have contributed to increasing EC and decreasing av. $P_2O_5$. Therefore, the effects of mine drainage contamination from the abandoned mine were derived primarily from contamination by heavy metals such as As. These may have been enhanced in toxicity (solubility) by the lowered pH, increased soil salinity (EC) and decreased av. $P_2O_5$. Our results suggest synergistic adverse effects on the plant and the nematode by decreasing osmotic potential and nutrient availability.

• 한국식물병리학회지
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• 제3권3호
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• pp.164-167
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• 1987

우리나라에서 발생하는 뿌리혹선충의 주요 종인 Meloidogyne hapla, M. arenaria, M. incognita 그리고 M. javanioa의 피해정도를 알기 위하여 pot당 0, 1,000, 10,000마리의 선충접종한 결과 감수정도는 M. javanica($Rutgers\;:\;80\%$, 복수2호 : $59\%$), M. incognita(Rutgers : $78\%$, 복수 2호 : $50\%$, M. arenaria($Rutgers\;:\;65\%$, 복수2호 : $24\%$), M. hapla($Rutgers\;:\;7\%$, 복수2호 : $15\%$)의 순이었고, M. hapla는 아열대인 필리핀에서의 Rutgers보다 우리나라에서의 Boksu 2에서 더 심한 피해를 나타내는 반면 M. arenaria, M. incognita 및 M. javanica는 필리핀에서의 Rutgers에서 더 피해가 심했다. 토마토의 생육에 미치는 영향은 풋트당 선충 10,000마리 접종구에서 Rutgers의 지상부 무게가 뿌리 무게나 초장보다 더 컸지만 선충 밀도가 낮은 1,000마리 접종구에서는 초장이나 지상부 무게가 감소하는 반면 뿌리 무게는 오히려 증가하는 경향이었다.

• 생명과학회지
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• 제10권4호
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• pp.403-407
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• 2000

잎들깨 재배지에서 직$\cdot$간접적으로 피해를 입히는 뿌리썩이선충(Pratylenchus spp.)의 생물학적 방제를 위해서 3종의 선충포식성 곰팡이, Arthrobotrys oligospora, A. conoides와 A. dactyloides의 선충방제 효과를 포장시험을 통하여 검정하였다. 3종의 Arthrobotrys는 1998년 잎들깨 재배지 토양에서 분리하였으며, 이들 곰팡이들은 한천배지상에서 끈끈이그물 또는 수축성 올가미와 같은 특이한 균사구조를 형성하여 뿌리썩이선층을 포획하는 것으로 관찰하였다. 야외포장 실험결과, 대조구에서는 40일 경과 후 식물기생성 선충 및 뿌리썩이선충의 밀도가 약 3.5배 증가한 반면 선충포식성 곰팡이 A. oligospora와 A. conoides 처리구에서는 단지 선충의 밀도가 큰 증감없이 접종 전의 수준을 유지하는 효과를 보였다. 그러나 A. dactyloides 처리구에서는 식물기생성 선충의 밀도를 약 65%, 뿌리썩이 선충의 밀도를 약 53% 감소시켜, 선충포식성 곰팡이의 생물학적 방제효과가 높게 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.

• 한국응용곤충학회지
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• 제29권1호
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• pp.14-19
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• 1990

부산, 경남, 경북, 전남, 전북 22개 지역 19수종 238본의 고사목에서 1989년 4월부터 9월까지 선충류와 곤충류를 조사한 결과, 소나무 재선충은 부산지역에서만 검출되었으며, 어리소나무 재선충은 진주와 진해에서 분포가 확인되었다. 고사목에서 분리.동정된 선충류는 9속 13종이었으며 6속은 미동정되었다. 동정된 선충 중 Diplogasteroides dimidius, Rhabdontolaimus adephagus, R.janae, Mikoletzkya diluta, M. ruminis, m. langcauda, Parasitorhabditis hylurgi, Panagrolaimus concolor, Panagrodontus dentatus, Prothallonema intermedium, Macrolaimus canadensis는 우리나라 미기록종이다. 한편, 고산목에서 채집된 곤충은 5목 9과 25속 27종이었는데 딱정벌레목이 3과 19속 22종으로 가장 많았다. 그중 나무종이 10속 12종으로 빈번히 채집되었으며, Hypothenemus eruditus가 꽃싸리, 싸리, 조록싸리, 만리화, 닥나무에서 채집되어 새 기주로 추가되었다. 소나무 재선충의 매개충인 솔수염하늘소는 복부에서의 선충 검출수가 가장 많았으며, 성충 한마리당 선충 보유수는 최대 127,535마리, 최소 2,616마리, 정균 42,817마리였다.

• 한국응용곤충학회지
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• 제43권1호
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• pp.27-34
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• 2004

더덕(Codonopsis lanceolata) 재배지에서 당근뿌리혹선충의 환경친화적 방제법을 구명코자 방제실험을 수행한 결과 당근뿌리혹선충 방제 실험에 사용된 방제제들(Bacillus thuringiensis, Paecilomyces lilacinus, fosthiazate, 한약제 추출물) 중 더덕의 발아를 향상시키는 것을 Bt와 한약제 추출물이었고, 억제시키는 것은 fosthiazated였다. Pot에서 미생물제에 의한 당근뿌리혹선충 밀도억제 효과는 Bt와 Paecilomyces lilacinus 모두 우수하였으나 fosthiazate 보다는 떨어지는 경향이었다. 또한 한약제 추출물도 방제효과가 우수하였다. 포장실험에서도 Paecilomyces lilacinus와 fosthiazate 처리 시 수확량이 가장 많았으며 수확된 더덕의 품질도 가장 우수하였다. 한약제추출물도 무처리에 비하여 더덕의 수량 증대에 효과가 있었고, 뿌리혹선충 감염지에서 키운 더덕을 이식한 것이 비감염지에서 키워 이식한 더덕에 비하여 수량 증가율이 저조하였다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.852-858
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• 2008

An extracellular protease (Mc1) was isolated from the nematode-trapping fungus Monacrosporium cystosporium by gel filtration, anion-exchange, and hydrophobic interaction chromatographies. This protease had a molecular mass of approximately 38 kDa and displayed an optimal activity at pH 7-9 and $56^{\circ}C$ (over 30 min). Its proteolytic activity was highly sensitive to the serine protease inhibitor PMSF (phenylmethylsulfonylfluoride, 0.1 mM), indicating that it belonged to the serine-type peptidase group. The Michaelis constant ($K_m$) and $V_max$ for substrate N-Suc-Ala-Ala-Pro-Phe-pNA were $1.67{\times}10^{-4}\;M$ and 0.6071 $OD_{410}$ per 30 s, respectively. This protease could degrade a broad range of substrates including casein, gelatin, BSA (bovine serum albumin), and nematode cuticle. Moreover, the enzyme could immobilize the free-living nematode Panagrellus redivivus and the pine wood nematode Bursaphelenchus xylophilus, suggesting that it might playa role in infection against nematodes. The encoding gene of Mc1 was composed of one intron and two exons, coding for a polypeptide of 405 amino acid residues. The deduced amino acid sequence of Mcl showed 61.4-91.9% identity to serine proteases from other nematode-trapping fungi. Our results identified that Mcl possessed biochemical properties including optimal reaction condition and substrate preference that are different from previously identified serine proteases.