• 한국토양비료학회지
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• 제49권4호
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• pp.401-408
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• 2016

The present study described the isolation of 2-methylbutyric acid (2-MBA) produced from Bacillus pumilus L1, to subsequently investigate its nematicidal activity for the control of the root-knot nematode. The results showed that 2-MBA could be purified by chromatographic techniques and was identified using nuclear magnetic resonance and liquid chromatography-mass spectrometry. Crude extract and partially purified compounds had a significant effect on the inhibition of egg hatchability and second-stage juvenile (J2) mortality. A dose-dependent effect of 2-MBA was observed for J2 mortality and egg hatchability. Egg hatchability was 69.2%, 59.9%, 32.7%, and 0.0% at 125, 250, 500, and $1000{\mu}g\;mL^{-1}$ of 2-MBA after 4 d of incubation, respectively. Meanwhile, J2 mortality was in the range of 24.4%-100.0% after 2 d of incubation, depending on the concentrations of 2-MBA used. A pot experiment also demonstrated that treatment of B. pumilus L1 culture caused a significant reduction in the number of galls, egg masses, and J2 population than that of the tap water (TW) control. However, as the B. pumilus L1 culture concentration was decreased, the efficacy of nematode control by treatment of B. pumilus L1 culture was reduced compared to that of TW. B. pumilus L1 inoculation at different concentrations also promoted cucumber plant growth. Therefore, our study demonstrated the potential of 2-MBA from B. pumilus L1 as a biocontrol agent against the root-knot nematode and a plant growth promoter for cucumber plants.

• 한국응용곤충학회지
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• 제45권1호
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• pp.79-85
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• 2006

국내 주요감자재배지의 식물기생선충 발생상을 밝히기 위해 2004년과 2005년에 제주, 예산, 김천, 고령, 홍천, 평창, 김제, 밀양, 남원, 강릉, 인제 등 11개 감자 주산지를 대상으로 선충속별 종류와 밀도를 조사하였다. 채집한 토양시료 50개 중 30개에서 뿌리혹선충 유충이 검출되었으며 밀도는 12-69마리/토양 100cc 정도로 비교적 낮았다. 식물기생선충류 중 Pratylenchus sp., Helicotylenchus sp, Ditylenchus sp., Tylenchus sp., and Tylenchorhynchus sp.가 지역별로 검출되었으나 대부분 밀도는 매우 낮게 나타났다. 채집한 토양을 토마토 뿌리에 접종 후 뿌리혹선충을 배양하여 PCR-RLFP에 의한 정밀동정 결과 제주, 밀양, 고령에서 채집한 뿌리혹선충 암컷에서 500 bp의 PCR 산물을 얻었으며 제한 효소 Dra I을 처리한 결과 290 및 230 bp의 밴드가 형성되어 당근뿌리혹선충(Meloidogyne hapla)으로 동정하였다.

• 식물병연구
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• 제20권2호
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• pp.112-118
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• 2014

본 연구는 키틴분해세균, 키틴 및 그들의 산물이 함유된 미생물제가 오이의 뿌리혹선충을 어느 정도 방제할 수 있는가를 알아보기 위하여 실시되었다. 미생물제는 3종의 키틴분해세균(Chromobacterium sp. C-61, Lysobacter engymogenes 및 Serratia plymuthica)을 키틴 + 최소기본배지에서 배양함으로서 조제되었다. 포트 조건에서 미생물제는 대조구에 비하여 오이의 생육을 증진시키고, 뿌리혹과 뿌리혹선충의 밀도를 감소시켰다. 비닐하우스에서 정식한 날부터 물 대신에 75배 희석된 미생물제를 5일 간격으로 6회 오이에 점적 관수하면, 30일 후 오이의 초장이 7% 증가하고 근권의 뿌리혹선충 밀도는 78% 감소되며, 60일 후에는 10%의 초장 증가와 69%의 밀도 감소를 나타냈다. 아울러, 이러한 효과는 미생물제가 직접 접촉된 부분에서만 일어났다. 한편, 뿌리혹선충에 심하게 감염되어 생육이 저조한 오이에 미생물제 원액을 10일 간격 3회 토양 관주하였을 경우에는 무처리구에서 37%의 오이가 죽었지만 처리구에서는 한 주도 죽지 않고, 37%의 생육 증가와 82%의 선충 감소를 보여 주었다. 따라서 본 미생물제는 오이 뿌리혹선충의 방제에 활용 가능하리라 판단되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1999년도 정기총회 및 춘계 학술발표회
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• pp.18.2-18
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• 1999

• Journal of Plant Biotechnology
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• 제4권2호
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• pp.45-52
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• 2002

A lot of SSRs (simple sequence repeats) in peach and pear from enriched genomic libraries and in peach from a cDNA library were developed. These SSRs were applied to other related species, giving phenograms of 52 Prunes and 60 pear accessions. Apple SSRs could also be successfully used in Pyrus spp. Thirteen morphological traits were characterized on the basis of the linkage map obtained from an $F_2$ population of peach. This map was compiled with those morphological markers and 83 DNA markers, including SSR markers used as anchor loci, to compare different peach maps. Molecular markers tightly linked to new root-knot nematode resistance genes were also found. A linkage map including disease related genes, pear scab resistance and black spot susceptibility, in the Japanese pear Kinchaku were constructed using 118 RAPD markers. Another linkage map, of the European pear Bartlett, was also constructed with 226 markers, including 49 SSRs from pear, apple, peach and cherry. Maps of other Japanese pear cultivars, i.e., Kousui and Housui, were also constructed. These maps were the first results of pear species.

• The Plant Pathology Journal
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• 제26권2호
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• pp.149-153
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• 2010

Biological and structural mechanisms of the nematode disease development in chili pepper caused by the root-knot nematode, Meloidogyne incognita, were investigated. Out of 39 chili pepper cultivars/lines tested, six were found resistant, while 33 were susceptible to M. incognita, of which a susceptible cultivar Chilseongcho and three resistant cultivar/lines CM334, 02G132 and 03G53 with different resistance degrees were selected for microscopic studies on the disease development. Gall formation was greatly reduced in the resistant cultivars/lines. Nematode penetration occurred both in the susceptible and resistant chili pepper roots; however, the penetration rates were significantly lowered in the three resistant peppers compared to the susceptible pepper cv. Chilseongcho. In the susceptible pepper, giant cells were extensively formed with no discernible necrosis around the nematode feeding sites. In the highly resistant pepper cultivar CM334, no giant cell was formed, but extensive necrosis formation was observed around the penetrating nematodes. In the other two resistant pepper lines (02G132 and 03G53), both giant cells and prominent necroses were formed, and the necrotic responses appeared to inhibit the further development of giant cells or accelerate their early degeneration. Although the nematode penetration was retarded significantly in the resistant cultivar/lines, all of the above results suggest that the disease resistance of pepper may be related to post-infectional defense mechanisms (nematode growth and development) more than pre-infectional ones (penetration and establishment). Variations in structural modifications in the resistant cultivar/lines may reflect their genetic differences related to the nematode resistance.

• 식물병연구
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• 제19권1호
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• pp.25-30
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• 2013

국내에서 시판되고 있는 토마토 36품종을 이용하여 국내 시설재배지에서 가장 많이 분포하고 있는 두 종의 뿌리혹선충, Meloidogyne arenaria와 M. incognita에 대한 저항성을 검정하였다. 방울토마토 중에서는 '텐텐', '캐딜락', '큐티', '스위트', '뽀또', '리코핀-9' 등 6품종, 완숙토마토 중에서 '러브리240', '도테랑다이아', '큐피랑', '도테랑마스터', '슈퍼도태랑', '도태랑시즌', '마이로꾸', '호용' 등 8품종, 대목은 '스페셜', '파이팅', '마그네트' 등 3품종이 두 종류의 뿌리혹선충에 모두 강한 저항성이었다.

• The Plant Pathology Journal
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• 제34권6호
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• pp.544-554
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• 2018

Tomato (Solanum lycopersicum) production in Ghana is limited by the root-knot nematode (Meloidogyne incognita, and yield losses over 70% have been experienced in farmer fields. Major management strategies of the root-knot nematode (RKN), such as rotation and nematicide application, and crop rotation are either little efficient and harmful to environments, with high control cost, respectively. Therefore, this study aims to examine morphometric variations of RKN populations in Ghana, using principal component analysis (PCA), of which the information can be utilized for the development of tomato cultivars resistant to RKN. Ninety (90) second-stage juveniles (J2) and 16 adult males of M. incognita were morphometrically characterized. Six and five morphometric variables were measured for adult males and second-stage juveniles (J2) respectively. Morphological measurements showed differences among the adult males and second-stage juveniles (J2). A plot of PC1 and PC2 for M. incognita male populations showed clustering into three main groups. Populations from Asuosu and Afrancho (Group I) were more closely related compared to populations from Tuobodom and Vea (Group II). There was however a single nematode from Afrancho (AF4) that fell into Group III. Biplots for male populations indicate, body length, DEGO, greatest body width, and gubernaculum length serving as variables distinguishing Group 1 and Group 2 populations. These same groupings from the PCA were reflected in the dendogram generated using Agglomerative Hierarchical Clustering (AHC). This study provides the first report on morphometric characterisation of M. incognita male and juvenile populations in Ghana showing significant morphological variation.

• 한국토양동물학회지
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• 제8권1_2호
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• pp.27-31
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• 2003

당근뿌리혹선충(Meloidogyne hapla)이 더덕(Codonopsis lanceolata)ml 생장에 미치는 영향을 구명하기 위하여 pot와 포장에서 실험을 수행하였다. 그 결과 당근뿌리혹선충의 밀도가 증가함에 따라 pot 실험에서는 더덕의 덩굴생장이 60%, 뿌리생장이 45% 억제되었다. 포장 실험에서는 밀도 수준별 생육차이가 뚜렷하지 않았다. 이 결과는 더덕 구당 선충 접종 밀도가 낮아 피해수준에 도달하지 않은 것으로 사료된다.

• The Plant Pathology Journal
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• 제33권3호
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• pp.249-263
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• 2017

This study aims to examine the potential reasons for the current prevalence of the fusarium wilt in the oriental melon. Twenty-seven Fusarium isolates obtained from oriental melon greenhouses in 2010-2011 were identified morphologically and by analysis of elongation factor-1 alpha gene (EF-$1{\alpha}$) and internal transcribed spacer (ITS) rDNA sequences as 6 Fusarium species (8 isolates of F. oxysporum, 8 F. commune, 5 F. proliferatum, 3 F. equiseti, 2 F. delphinoides, and 1 F. andiyazi), which were classified as same into 6 EF-$1{\alpha}$ sequence-based phylogenetic clades. Pathogenicity of the Fusarium isolates on the oriental melon was highest in F. proliferatum, next in F. oxysporum and F. andiyazi, and lowest in the other Fusarium species tested, suggesting F. proliferatum and F. oxysporum were major pathogens of the oriental melon, inducing stem rots and vascular wilts, respectively. Oriental melon and watermelon were more susceptible to F. oxysporum than shintosa and cucumber; and cucumber was most, oriental melon and watermelon, medially, and shintosa was least susceptible to F. proliferatum, whose virulence varied among and within their phylogenetic subclades. Severe root-knot galls were formed on all the crops infected with Meloidogyne incognita; however, little indication of vascular wilts or stem and/or root rots was shown by the nematode infection. These results suggest the current fungal disease in the oriental melon may be rarely due to virulence changes of the fusarium wilt pathogen and the direct cause of the severe root-knot nematode infection, but may be potentially from other Fusarium pathogen infection that produces seemingly wilting caused by severe stem rotting.