• The Plant Pathology Journal
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• v.17 no.5
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• pp.257-263
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• 2001

Species of the genus Orobanche are parasitic flowering plants, holoparasites, which cling to the roots of green plants. Their tiny seeds (200 x $250\mu\textrm{m}$) germinate in response to chemical stimuli produced by host and some non-host plants. Successful contact with their host leads to development of haustoria for obtaining water and food. The shoots above the ground expose flowers and disseminate seeds. Several samples of Orobanche ramosa, O. crenata, O. cernua, and O. egyptiaca were collected from different localities in Jordan. These samples showed one of the following disease symptoms: dry rot at the base of the stem; general deterioration and expanded lesion from base upward; soft tissue maceration of stem; and black rot of flower parts with incomplete maturation of the ovary and seeds. Isolation from diseased stems and seeds was made on three different mycological media. Several fungi were isolated, mainly, Fusarium spp., Alternaria alternata, Rhizoctonia sp., Dendrophora sp., Chaetomium sp., and an ascomycetus fungus with a perithecium. Pathogenicity tests showed that Fusarium spp. and Alternaria alternata attacked healthy living tissue of Orobanche spikes. These fungi caused lesions of black soft rot and complete deterioration within 5-7 days. They also attacked Orobanche seeds, arresting their germination and causing maceration of non-germinated and germinated seeds after 5-7 days of incubation. Meanwhile, Dendrophora sp. and Chaetomium sp. caused limited lesion at first, but were able to colonize the tissue as it aged and senesced. This study showed the presence of a potential endogenous pathogenic fungi in Jordan, which can be investigated as a biological control for Orobanche.

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.121-129
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• 2009

In 2007, a total of 77 isolates of Fusarium spp. were obtained from ear rot symptoms of corns collected from 5 locations in Gangwon Province, Korea. The fungal isolates were identified based on their morphological features. Out of the isolates, fifteen isolates were identified as Fusarium verticillioides which formed microconidia in long chains on monophialides. Four isolates were identified as F. subglutinans which formed microconida only on false heads. Six isolates were identified as F. graminearum which produced red pigment in PDA culture. Besides these Fusarium species, F. napiform, F. nygamai, and F. oxysporum were identified from the rest isolates. To assess for genetic diversity of the isolates, a random amplified polymorphic DNA(RAPD) technique was carried out using URP primers. The results from the RAPD analysis showed that the isolates from corn were divided into 6 groups. These RAPD groups of the Fusarium species corresponded to morphological characters of the Fusarium species. The phylogenetic analysis of most isolates by DNA sequencing of EF-1$\alpha$ gene corresponded to morphological characters of the Fusarium species. The results of pathogenicity tests by two inoculation methods revealed that F. verticillioides, F. graminearum and F. subglutinans are strongly pathogenic to corn stalks.

• Research in Plant Disease
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• v.17 no.3
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• pp.369-375
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• 2011

Fusarium verticillioides (teleomorph: Gibberella moniliformis), a member of the Gibberellea fujikuroi species complex, causes rots of corn stalks and ears, and produces a group of mycotoxins known as fumonisins that are harmful to animals and humans. Here, we focus on the development of a species-specific PCR primer set for differentiating F. verticillioides from other fumonisin-producing Fusarium species belonging to the species complex, such as F. proliferatum, F. fujikuroi, and F. subglutinans that are frequently associated with corn. The specific primers (RVERT1 and RVERT2) derived from the nucleotide sequences of RNA polymerase II beta subunit (RPB2) gene amplified a 208 bp-DNA fragment from only F. verticillioides isolates among the potential fumonisin-producing species examined; all of these isolates were shown to carry FUM1 required for fumonisin biosynthesis. The PCR detection limit using this specific primer set was approximately 0.125 pg/${\mu}l$ genomic DNA of F. verticillioides. In addition, the F. verticillioides-specfic fragment was successfully amplified from genomic DNAs of corn samples contaminated with Fusarium spp. This primer set would provide a useful tool for the detection and differentiation of potential fumonisin-producing F. verticillioides strains in cereal samples.

• Research in Plant Disease
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• v.24 no.4
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• pp.308-312
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• 2018

We analyzed rice sample with scab (collected in 2017) for fungal occurrence and found that frequency of Fusarium spp. was the highest among fungal genera. Within Fusarium, Fusarium asiaticum-nivalenol type dominated as 79%. Among mycotoxins, zearalenone was the highest toxin detected (1117 ng/g), followed by deoxynivalenol (163 ng/g), 15-acetyl deoxynivalenol (155 ng/g), nivalenol (110 ng/g). Analysis of mycotoxin levels in scabby and healthy grains (collected in 2015) revealed that both grain samples were contaminated with zearalenone. However, level difference of zearalenone between the samples was over 5 times as the scabby samples were 1400-2370 ng/g, while healthy ones were 240-430 ng/g. This result indicates that scabby grains should be removed when harvest to reduce zearalenone contamination in rice.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.383-386
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• 2012

Streptomyces spp. were isolated from rhizosphere in fallow lands. The Streptomyces spp. were identified as Streptomyces griseus (MSS181), Streptomyces griseoaurantiacus (MSS269), Streptomyces microflavus (MSS275), Streptomyces herbaricolor (MSS276) based on 16S rRNA gene sequences. Afterwards, cucumber, pepper, tobacco and tomato were drenched with the isolates at early growth stages and plant growth such as height and dry weight of plants was measured. By treatment of Streptomyce spp., plant height of cucumber was increased by 16-29% compared to the control, But there were no statistically significant differences in dry weight. When the same isolates were treated on chili-pepper, plant height and dry weight of chili-pepper were increased respectively by 10-19% and 19-25% compared to the control. The dry weight of tobacco and tomato were increased by 44-73% and 65-165%, respectively compared to the control. When antifungal activities of the isolates were tested against plant pathogenic fungi, Streptomyces microflavus (MSS275) effectively inhibited the mycelial growth of Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani and Sclerotinia sclerotiorum.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.540-549
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• 2016

Plant residues serve as substrates for the proliferation and overwintering of plant pathogenic fungi in soil. Effects of the biocontrol fungus Trichoderma harzianum on the colonization of wheat straw by the plant pathogenic fungus Fusarium solani were investigated under different soil moisture regimes (-50 vs. -500 kPa) in non-sterile soil. T. harzianum ThzID1-M3 and/or F. solani were added along with wheat straw to non-sterile soils. ThzID1-M3, other Trichoderma species, and F. solani were monitored for a 21-day period using quantitative PCR. ThzID1-M3 reduced the colonization of F. solani on wheat straw (p < 0.05) under both moisture regimes, and F. solani reduced the colonization by ThzID1-M3 and other Trichoderma species (p < 0.05), thus suggesting competitive inhibition between ThzID1-M3 and F. solani. Colonization by ThzID1-M3 and generic Trichoderma was improved in the wet soil (p < 0.05), but colonization by F. solani did not differ between the two moisture conditions. Thus, the inhibitory effect of ThzID1-M3 was greater in the wet soil (p < 0.05). The growth competition between ThzID1-M3 and F. solani to colonize plant debris suggests that the biocontrol fungus T. harzianum may reduce the potential of the plant pathogen, F. solani, to survive and proliferate on crops.

• Journal of Microbiology
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• v.38 no.2
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• pp.66-73
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• 2000

To investigate the genetic relationship among 12 species belonging to the Fusarium section Martiella, Dlaminia, Gibbosum, Arthrosporiella, Liseola and Elegans, the internal transcribed spacer(ITS) regions of ribosomal DNA (rDNA) were amplified with primer pITS1 and pITS4 using the polymerase chain reaction(PCR). After the amplified products were digested with 7 restriction enzymes, restriction fragment length polymorphism (RFLP) patterns were analyzed. The partial nucleotide sequences of the ITS region were determined and compared. Little variation was observed in the size of the amplified product having sizes of 550bp or 570bp. Based on the RFLP analysis, the 12 species studied were divided into 5 RFLP types. In particular, strains belonging to the section Martiella were separated into three RFLP types. Interestingly, the RFLP type of F. solani f. sp. piperis was identical with that of isolates belonging to the section Elegans. In the dendrogram derived from RFLP analysis of the ITS region, the Fusarium spp. examined were divided into two major groups. In general, section Martiella excluding F. solani f. sp. piperis showed relatively low similarity with the other section. The dendrogram based on the sequencing analysis of the ITS2 region also gave the same results as that of the RFLP analysis. As expected, 5.8S, a coding region, was highly conserved, whereas the ITS2 region was more variable and informative. The difference in the ITS2 region between the length of F. solani and its formae speciales excluding F. solani f. sp. piperis and that of other species was caused by the insertion/deletion of nucleotides in positions 143-148 and 179-192.

• Korean journal of applied entomology
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• v.22 no.3 s.56
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• pp.203-207
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• 1983

Biological, physical and chemical characteristics of suppressive and conducive soils to ginseng root rot were investigated. Population of antagonistic microorganisms to Fusarium solani was much higher in suppressive soils than in conducive soils, whereas the numbers of Fusarium species were smaller in suppressive soils. Mycelial growth and chlamydospore formation of Fusarium solani were inhibited in suppressive soils. In the water extract of suppressive soils, lysis of germination tube and macroconidia of F. solani was occurred by antagonistic microorganisms at 4 hours after treatment. There were no significant differences in physical and chemical characteristics between supressive soils and conducive soils to ginseng root rot, however, clay content of suppressive soils was a little higher than that of conductive soils.

• The Korean Journal of Mycology
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• v.20 no.4
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• pp.337-346
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• 1992

Trichoderma spp. are an effective control agent for damping-off or other plant diseases. The interaction between. T. hamatum and Rhizoctonia solani on the rhizosphere or surface soil were examined to assess the possible roles of antibiosis or competition in the mechanisms of biological control agents as a basic research. In a proportional comparison, total bacteria, fungi, actinomycetes and Trichoderma spp were 65%, 8.8%, 25.9% and 0.28% respectively in their distribution in the soil. Among Trichoderma spp isolated, the 5 species of Trichoderma spp were indentified as T. koninggii, T. pseudokoninggii, T. aureoviridi, T. hamatum and T. viride respectively. In a mycoparasitic test, one isolate of T. hamatum strain Tr-5 showed an enzymatic ability to break fungal hyphae into piecies and infected on the R. solani hyphae showing a parasitism. Spore germination of the all isolates of Trichoderma spp showed a 1.7-7.3% of germination in natural soil conditions, but the percentage was high in sterile soil indicating all the natural soil were fungistatic on conidia of Trichoderma spp. In rhizosphere competent assay in pea plant, the antagonistic T. hamatum, T. viride, T. koninggii, T. pseudokoninggii showed a colonizing upper soil depth in rhizosphere around 1-3 cm in root zone, but the colonizing ability was much reduced along the deeper the soil depth. Propagule density was decreased in deeper the soil layer. Disease development rate treated alone with plant pathogens, Fusarium solani, Rhizoctonia solani, Cylindrocarpon destructans increased, but disease incidence rate reduced in treatment with combinations with antagonistic T. hamatum strain Tr-5.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.600-613
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• 2023

Fusarium oxysporum is the main pathogen causing Fusarium basal rot in onion (Allium cepa L.), which incurs significant yield losses before and after harvest. Among management strategies, biological control is an environmentally safe and sustainable alternative to chemical control. In this study, we isolated and screened bacteria for antifungal activity against the basal rot pathogen F. oxysporum. Isolates 23-045, 23-046, 23-052, 23-055, and 23-056 significantly inhibited F. oxysporum mycelial growth and conidial germination. Isolates 23-045, 23-046, 23-052, and 23-056 suppressed the development of Fusarium basal rot in both onion seedlings and bulbs in pot and spray inoculation assays. Isolate 23-055 was effective in onion seedlings but exhibited weak inhibitory effect on onion bulbs. Based on analyses of the 16S rRNA and rpoB gene sequences together with morphological analysis, isolates 23-045, 23-046, 23-052, and 23-055 were identified as Bacillus thuringiensis, and isolate 23-056 as Bacillus toyonensis. All five bacterial isolates exhibited cellulolytic, proteolytic, and phosphate-solubilizing activity, which may contribute to their antagonistic activity against onion basal rot disease. Taken together B. thuringiensis 23-045, 23-046, 23-052, and 23-055 and B. toyonensis 23-056 have potential for the biological control of Fusarium basal rot in onion.