• Research in Plant Disease
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• v.20 no.2
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• pp.112-118
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• 2014

A liquid bio-formulation containing chitinolytic bacteria, chitin and their products was assessed for its potential biological control against root-knot nematodes on cucumber. The bio-formulation was prepared by cultures of three chitinolytic bacteria, Chromobacterium sp. strain C-61, Lysobacter engymogenes and Serratia plymuthica in minimal medium supplemented with chitin. Under pot conditions, the bio-formulation showed better growth of cucumber plants, and less root galls and population density of Meloidogyne spp. than control media without the bio-formulation. In a greenhouse, 75-fold diluted bio-formulations were treated instead of water around cucumber plants through hoses for drip irrigation six times at 5-day intervals from the transplanting date. After 30 and 60 days, the treatment provided about 7% and 10% enhancement in the plant height and about 78% and 69% reduction in population density of Meloidogyne spp. in the rhizosphere, respectively. In addition, the experiments showed that the control effects occurred only in the soils contacted with the bio-formulation. Undiluted bio-formulations were drenched three times at 10-day intervals around cucumber plants severely infested with Meloidogyne spp. The treatment showed about 37% plant enhancement without dead plants compared with 37% death in the untreated control, and about 82% nematode reduction. These results suggest that the bio-formulation can be practically used to control the root-knot nematode on cucumber.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.159-163
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• 2001

Influence of soil temperature [accumulated degree-day for the base temperature $5^{\circ}$($\textrm{DD}_5$)] on the development of Meloidogyne arenaria were studied in a winter grown oriental melon greenhouse in Seongju, Korea. Egg masses were first observed on roots at the accumulation of 565 $\textrm{DD}_5$(40 days after transplanting), suggesting that the nematode has completed the first generation in 40 days. Second-stage juveniles (J2) densities were lowest at 863 $\textrm{DD}_5$ in April, first increased at 1,334 $\textrm{DD}_5$ in May, peaked at 2,951 $\textrm{DD}_5$ in July, and decliner thereafter. Development of egg masses and J2 density in soil revealed that M. arenaria could develop in 7-8 generations in a year in the greenhouse. Degree-day monitoring, therefore, could aid to predict nematode development in soil and can be valuable tool a to develop root-knot nematode control strategies.

• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.53-56
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• 1987

The effect of nematicides on root-knot nematode were investigated in the mulberry nursery farm of Jeonnam province from 1985 to 1986. The nematicides applied were Fenamiphos, D-D(92%), Aldicarb, D-D(55%), Ethoprop and Carofuran. The control effects of nematicides used were similar in two years (1985 and 1986). The Fenamiphos and D-D(92%) both were a highly effective than any of Aldicarb, D-D (55%) and Ethoprop, Carbofuran. Mulberry sampling showed good growth when the above nematicides were applied.

• Journal of Plant Biotechnology
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• v.4 no.2
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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.

• Journal of Ginseng Research
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• v.7 no.1
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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.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.115-115
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• 1985

• Research in Plant Disease
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• v.18 no.4
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• pp.370-375
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• 2012

Ninety two pepper (Capsicum annuum L.) cultivars were screened for resistance to two common species of root-knot nematodes, Meloidogyne incognita and M. arenaria. All 92 pepper cultivars were resistant to M. arenaria (0-3 eggmass/plant) but were susceptible to M. incognita (76-678 eggmass/plant). Susceptibility to M. incognita were slightly differed; 'Geomok' and 'Shintaepung' had relatively less eggmass (<100 eggmass/plant) when compared to those 29 very susceptible culivars such as 'Bulggotcheoreum' (>300 eggmass/plant). Therefore, pepper is highly recommended as a high-valued rotation crop to only those greenhouses infested with M. arenaria, but should restrict for M. incognita.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.91-100
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• 2008

Melting curve analysis of fluorescently labeled DNA fragments is used extensively for genotyping single nucleotide polymorphism(SNP). Here, we evaluated a SNP genotyping method by melting curve analysis with the two probe chemistries in a 384-well plate format on a Roche LightCycler 480. The HybProbe chemistry is based on the fluorescence resonance energy transfer(FRET) and the SimpleProbe chemistry uses a terminal self-quenching fluorophore. We evaluated FRET HybProbes and SimpleProbes for two SNP sites closely linked to two quantitative trait loci(QTL) for southern root-knot nematode resistance. These probes were used to genotype the two parents and 94 $F_2$ plants from the cross of PI 96354$\times$Bossier. The SNP genotypes of all samples determined by the LightCycler software agreed with previously determined SSR genotypes and the SNP genotypes determined on a Luminex 100 flow cytometry instrument. Multiplexed HybProbes for the two SNPs showed a 98.4% success rate and 100% concordance between repeats two of the same 96 DNA samples. Also, we developed a HybProbe assay for the Rcs3 gene conditioning broad resistance to the frogeye leaf spot(FLS) disease. The LightCycler 480 provides rapid PCR on 384-well plate and allows simultaneous amplification and analysis in approximately 2 hours without any additional steps after amplification. This allowed for a reduction of the potential contamination of PCR products, simplicity, and enablement of a streamlined workflow. The melting curve analysis on the LightCycler 480 provided high-throughput and rapid SNP genotyping and appears highly effective for marker-assisted selection in soybean.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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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.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1510-1515
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• 2014

Lysobacter capsici YS1215 isolated from soil previously showed nematicidal potential for biological control of the root-knot nematode. In this study, lactic acid, a nematicidal compound, was isolated from culture filtrate of YS1215, and its ovicidal activity was investigated. Purification and identification of lactic acid were performed by a series of column chromatographies and identified by $^1H$ and $^{13}C$ NMR spectra and GC-MS analysis. Our results showed that bacterial culture filtrate containing lactic acid significantly inhibited egg hatching. The lowest egg hatch rate (5.9%) was found at a high concentration ($25 {\mu}l/ml$) of lactic acid at 5 days after incubation, followed by 20 (15.2%), 15 (23.7%), 10 (29.8%), and $5(36.4%){\mu}l/ml$, while egg hatching in the control (sterile distilled water) was 44.5%. This is the first report of lactic acid as an ovicidal compound, and it may be considered as an alternative of chemical pesticide against root-knot nematodes.