• The Korean Journal of Mycology
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• v.39 no.1
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• pp.11-15
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• 2011

To provide basic information for Verticillium spp., molecular methods were applied to analyze genetic characteristics within Verticillium spp. including Verticillium dahliae, isolated from diseased plants in two regions of Korea. Five Korean isolates of V. dahliae causing Verticillium wilt on chrysanthemum were analyzed, together with six other Verticillium spp., using mitochondrial small subunit rRNA gene (rns) sequence and random-amplified polymorphic DNA (RAPD). In a phylogenetic tree based on rns region sequences, Korean V. dahliae isolates formed a single clade with foreign isolates, whereas the other Verticillium spp. formed separate groups. In addition to rns sequence analysis, a dendrogram based on RAPD fragment patterns also showed clustering of all V. dahliae isolates into one group, separate from the six different Verticillium spp., and the V. dahliae isolates formed three subgroups which corresponded to the regions of origin, Kumi, Busan city and Canada. This indicates that high genetic variation exists between regions, although the fungus was isolated from the same host plant, chrysanthemum. These results provide the foundation for the study of genetic diversity and relationships among V. dahliae isolates in Korea.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.184-187
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• 2003

Verticillium wilt was first observed in 2001 on potatoes (Solanum tuberosum) cv. Superior at Daegwallyong area, one of the major seed potato producing areas in Korea. The wilted potato plants showed typical symptoms including gradual yellowing and interveinal necrosis. There was discoloration in the vascular tissues of the infected stems which turned light brown. Fungal isolates from discolored vascular tissues were whitish to creamy with folding on potato dextrose agar medium, where they used to produce resting dark mycelia but no micro-sclerotia. Conidiophores were septate with side branches, swelled at the base, and arranged in a whorl. Conidia were 2.5-11.2$\times$2.0-4.5 $\mu\textrm{m}$ um in size and were borne in small clusters at the tips of phialides. Optimal temperature range for mycelial growth was $25-30^{\circ}C$. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium albo-atrum Reink & Berth. Pathogenicity tests by root dipping method revealed that the fungus caused the same symptoms as observed in naturally infected potato plants. This is the first report of Verticillium wilt on potato caused by Verticillium albo-atrum in Korea.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1040-1050
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• 2024

To isolate and analyze bacteria with Verticillium wilt-resistant properties from the fermentation residue of kitchen wastes, as well as explore their potential for new applications of the residue. A total of six bacterial strains exhibiting Verticillium wilt-resistant capabilities were isolated from the biogas residue of kitchen waste fermentation. Using a polyphasic approach, strain ZL6, which displayed the highest antagonistic activity against cotton Verticillium wilt, was identified as belonging to the Pseudomonas aeruginosa. Bioassay results demonstrated that this strain possessed robust antagonistic abilities, effectively inhibiting V. dahliae spore germination and mycelial growth. Furthermore, P. aeruginosa ZL6 exhibited high temperature resistance (42℃), nitrogen fixation, and phosphorus removal activities. Pot experiments revealed that P. aeruginosa ZL6 fermentation broth treatment achieved a 47.72% biological control effect compared to the control group. Through activity tracking and protein mass spectrometry identification, a neutral metalloproteinase (Nml) was hypothesized as the main virulence factor. The mutant strain ZL6ߡNml exhibited a significant reduction in its ability to inhibit cotton Verticillium wilt compared to the strain P. aeruginosa ZL6. While the inhibitory activities could be partially restored by a complementation of nml gene in the mutant strain ZL6CMߡNml. This research provides a theoretical foundation for the future development and application of biogas residue as biocontrol agents against Verticillium wilt and as biological preservatives for agricultural products. Additionally, this study presents a novel approach for mitigating the substantial amount of biogas residue generated from kitchen waste fermentation.

• The Korean Journal of Mycology
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• v.27 no.3 s.90
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• pp.191-197
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• 1999

The phylogenetic position of Gliocladium and its related taxa were investigated, using the neighbor-joining method of the sequences from internal transcribed spacers (ITS1 and ITS2) and 5.8S ribosomal DNA (rDNA). It was focused especially on the generic concept by comparing with the related genera such as Trichoderma, Hypocrea, Verticillium, Penicillium and Talaromyces. Gliocladium species and its related genus were divided into three groups by the phylogenetic analysis using the neighbor-joining method. The first group includes Penicillium-like strains such as Penicillium, Tararomyces, Verticillium and one species of Gliocladium (G. cibotii JCM 9203 and JCM 9206). Especially, Gliocladium cibotii JCM 9203 is thought to be the similar species with Verticillium bulbillosum JCM 9214. Between these two species, Gliocladium cibotii and Verticillium bulbillosum, the intraspecies concept needs to examined with culture condition. and morphological properties. The second group includes two species Verticillium, Verticillium tricorpus and Verticillium albo-atrum which extracted from the GenBank database in NCBI (National Center for Biotechnology Information). Trichoderma-like strains, such as Trichoderma, Hypocrea and several species of Gliocladium are included in the third group. Also, Gliocladium penicillioides IFO 5869 and Gliocladium catenulatum ATCC 10523 formed the subgroup of Trichoderma-like strains. The species of Gliocladium were dispersed in Trichoderma-like and Penicillinum-like group, and only one species of Gliocladium cihotii used in our study was located in Penicillium-like genus group. The species of Verticillium appeared in all three groups and the species of Trichoderma formed the monophylogeny with Hypocrea (telemorph). Also, Gliocladium virens was grouped with Trichoderma harzianum with a high bootstrap value, supporting that Gliocladium virens is to be placed in Trichoderma. The results suggest that Gliocladium is polyphyletic, and is more Trichoderma-like than Penicillium-like.

• Mycobiology
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• v.46 no.3
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• pp.254-259
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• 2018

Okra (Abelmoschus esculentus (L.) Moench) has gained more popularity as an economically significant plant for its nutritional and medicinal value, especially in China. During 2014-2016, the root disease of okra was discovered in four okra commercial fields surveyed in China. A fungul was isolated from the infected tissues, and was identified by Verticillium dahliae based on morphological characteristics. Pathogenicity test demonstrated that the fungus was pathogenic on okra, and fulfilled Koch's postulates. The analysis of three sequences revealed 99-100% identity with the reported V. dahliae strain in GenBank. Neighbor-joining analysis of the gene sequences revealed that the representative isolates were clustered with V. dahliae. To the best of our knowledge, this is the first report of Verticillium wilt of okra in China.

• Microbiology and Biotechnology Letters
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• v.10 no.3
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• pp.197-203
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• 1982

The protopectinase from the culture extract of a Verticillium sp. was purified about 1000 fold by ammonium sulfate fractionation, DEAE-Sephadex treatment and Sephadex G-75 column chromatography. The purified enzyme was homogeneous on electrophoresis and its molecular weight was estimated to be 38000 by Andrew's gel filtration, method. The enzyme was almost stable under the temperature of 4$0^{\circ}C$ and within the pH range of 3-5. Its optimum pH and temperature were 4 and 4$0^{\circ}C$, respectively. The activity was markedly inhibited by galacturonic acid. The purified enzyme was able to macerate various kinds of plant tissues, such as radish, cucumber, onion, carrot, and potato. It also reduced the viscosity of pectin solution more rapidly than that of pectic acid solution and showed no lyase or CMCase activity.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.145-148
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• 2002

The virulence of five Verticillium lecanii strains against greenhouse whiteflies, Trialeurodes vaporariorum, was tested at various temperatures as a major environmental factor. Strain CS-626 was found to be the most durable strain at a broad temperature range, and highly virulent against greenhouse whiteflies in a detached-leaf bioassay. In a tomato plant pot experiment, the $LT_{50}\;and\;LC_{50}$ of the CS-626 strain were 6.2 days and $2.3{\times}10^6$ conidia/ml, respectively. The optimal concentration of CS-626 for successful infection was $1{\times}10^8$conidia/ml. These results indicate that the CS-626 strain of Verticillium lecanii has a strong potential for effectively controlling greenhouse whiteflies.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.382.2-382
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• 2001

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.45-49
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• 2004

Verticillium tenerum was detected from the samples of potato (Solanum tuberosum L.) and pumpkin (Cucurbita maxima Duch.) in Korea. The samples on which this species was detected were potato tubers collected from Pyungchang and Gimjae, and fruits and seeds of pumpkin from Yeonchon in 2003. The conidiophores of the fungus produced mainly three to five phialides in verticil. The phialides were narrow, flask-shaped, only very slightly swollen at the base, and taper subulately to a narrow neck. They were hyaline, $10{\sim}26{\times}2{\sim}5\;{\mu}m$. The conidia were formed in slimy heads, and were oval to ellipsoidal, pale reddish-brown, $2.5{\sim}7.5{\times}2{\sim}4\;{\mu}m$. The colony on the substrata was unique, showing brick-red color. This is the first report on the distribution of Verticillium tenerum in Korea.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.45-52
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• 1982

A fungus with the highest protopectinase productivity was selected among 205 strains isolated from the soil and identified as a Verticillium sp. The Verticillium sp. was cultivated on wheat bran and the crude extruct of its culture medium showed the highest protopectinase activity on the following conditions: 3 days of cultivation time, 27$^{\circ}C$ of cultivation temperature, 1.2 $m\ell$/g wheat bran of water content, and reinforcement of ammonium nitrate and calcium chloride at the concentration of 0.5 and 0.02%, respectively. The optimum conditions for pectin production from Citrus peel pulp by the protopectinase were consequently obtained as follows: 20$m\ell$/g of liquid volume-to-pulp weight ratio, 4$0^{\circ}C$ of reaction temperature, and 4 of reaction pH. The higher the enzyme concentration, the better the yield of pectin and the shorter the reaction time. Total 45.6mg of pectin/g peel was produced by 1 hour reaction at the enzyme concentration of 10.5 units/$m\ell$. Molecular weight of the pectin produced by the enzyme was estimated to be about 62,000 by Smit and Bryant's method.