• Journal of Microbiology and Biotechnology
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• 제34권5호
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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 Plant Pathology Journal
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• 제19권3호
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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.

• The Plant Pathology Journal
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• 제16권3호
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• pp.156-161
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• 2000

A wilt disease occurred on greenhouse-grown eggplants at Yeojoo, Korea in 1997. The wilted eggplants had leaves with gradual yellowing, interveinal necrosis, and marginal crinkling. Vascular tissues of diseased stems were discolored, turned black, and microsclerotia developed at the base of stems. The disease progressed from lower parts of the plants upward. Fungal isolates from discolored vascular tissues were initially whitish to cream color on potato-dextrose agar (PDA) plate, which later turned black due to the formation of microsclerotia. Conidiophores were erect, hyaline, verticillately branched, and had 3 or 4 phialides arising at each node. Phialides were hyaline, arranged in whorls, and measured as 17.5-32.5 x 2-3$\mu\textrm{m}$. Conidia were hyaline, ellipsoidal to sub-cylindrical, mainly one-celled, and measured as 5-8.8 x 2-4$\mu\textrm{m}$. Conidia were borne in small clusters at the tips of phialides. Microsclerotia formed on PDA plates, and consisted of globular cells that formed irregular masses of various shapes. Chlamydospores were absent. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium dahliae Klebahn. Pathogenicity tests by root cutting, root dipping or soil drenching resulted in similar symptoms observed in the naturally infected eggplants. This is the first report on occurrence of Verticillium wilt of eggplant in Korea.

• The Plant Pathology Journal
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• 제17권6호
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• pp.382.2-382
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• 2001

• Mycobiology
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• 제46권3호
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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.

• The Plant Pathology Journal
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• 제17권4호
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• pp.222-226
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• 2001

In 1997, 103 isolates of Verticillium were obtained from roots and stems of tomato plants showing wilt symptoms in greenhouses in eight areas of Korea. Out of these isolates, 75 were edintified as V. dahliae while 28 were identified as V. albo-atrum based on their morpho-logical and cultural characteristics. Both Verticillium species produced colonies with conidiophores, which were more or less erect, hyaline, with verticillate branches, and with 3-4 phialides at each node. V. dahliae produced microsclerotia, while V. albo-atrum produced resting dark mycelium. Optimum temperatures for mycelial growth of V. dahliae and V. albo-atrum on PDA were 22 and $26^{\circ}$, respectively. Mycelial growth of V. albo-atrum was slower than that of V. dahliae. Pathoge-nicity tests revealed that tomato cvs. Zuikoh No. 102, Kyoryokubeiju No. 2, Zuiken, Kagimuza, and Momotaro were susceptible to V. albo-atrum, while cvs. Zuikoh No. 102 and Kyoryokubeiju No.2 were susceptible to V. dahliae.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1149-1161
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• 2014

Cotton plants were sampled and ranked according to their resistance to Verticillium wilt. In total, 642 endophytic fungi isolates representing 27 genera were recovered from Gossypium hirsutum root, stem, and leaf tissues, but were not uniformly distributed. More endophytic fungi appeared in the leaf (391) compared with the root (140) and stem (111) sections. However, no significant difference in the abundance of isolated endophytes was found among resistant cotton varieties. Alternaria exhibited the highest colonization frequency (7.9%), followed by Acremonium (6.6%) and Penicillium (4.8%). Unlike tolerant varieties, resistant and susceptible ones had similar endophytic fungal population compositions. In three Verticillium-wilt-resistant cotton varieties, fungal endophytes from the genus Alternaria were most frequently isolated, followed by Gibberella and Penicillium. The maximum concentration of dominant endophytic fungi was observed in leaf tissues (0.1797). The evenness of stem tissue endophytic communities (0.702) was comparatively more uniform than the other two tissues. Eighty endophytic fungi selected from 27 genera were evaluated for their inhibition activity against highly virulent Verticillium dahliae isolate Vd080 in vitro. Thirty-nine isolates exhibited fungistasis against the pathogen at varying degrees. Seven species, having high growth inhibition rates (${\geq}75%$), exhibited strong antifungal activity against V. dahliae. The antifungal activity of both volatile and nonvolatile metabolites was also investigated. The nonvolatile substances produced by CEF-818 (Penicillium simplicissimum), CEF-325 (Fusarium solani), CEF-714 (Leptosphaeria sp.), and CEF-642 (Talaromyces flavus) completely inhibited V. dahliae growth. These findings deepen our understanding of cotton-endophyte interactions and provide a platform for screening G. hirsutum endophytes with biocontrol potential.

• 한국균학회지
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• 제39권1호
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• pp.11-15
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• 2011

국내 Verticillium dahliae 균주를 공시하여 다른 Verticillium 종과의 유전적 차이와 다양성을 밝히고자 국내 두 지역으로 부터 분리한 V. dahliae를 포함한 7종의 Verticillium속 14균주를 대상으로 mitochondrial small subunit rRNA gene (rns) 영역 염기서열 분석과 random-amplified polymorphic DNA(RAPD)를 실시하였다. rns 영역 염기서열의 분석에서 국내 분리균인 5개의 V. dahliae균주는 Verticillium속 내 다른 종들과 달리 하나의 그룹을 형성하였고, 외국 균주들과도 동일한 그룹을 이루었다. rns 영역 염기서열 분석뿐만 아니라 RAPD 분석에서도 Verticillium속의 다른 종들과 구별되어 V. dahliae가 한 그룹을 형성하였으나 V. dahliae 균주간에 형성된 세 개의 소그룹을 통하여 동일한 국화과 작물로 부터 분리한 V. dahliae 간에 분리된 지역에 따라 유전적 다양성이 존재함을 확인하였다. 이러한 결과는 국내 V. dahliae의 유전적 다양성연구와 유연관계분석에 기초적인 자료로 사용될 것이다.

• 한국균학회지
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• 제47권4호
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• pp.437-441
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• 2019

국화에 발생하는 반쪽시들음병은 Veriticillium dahliae에 의해 발생하는 진균병으로 국화 재배농가에 상당한 경제적 손실을 야기한다. 일반 식물병원균을 동정하는 방법으로는 병원균을 진단하기까지 상당한 시간이 소요된다. 본 연구에서는V. dahliae를 신속하고 특이적으로 진단하기 위하여 등온증폭기술 (Loop-mediated isothermal amplification, LAMP)을 적용한 검출법을 개발하였다. 이 방법은 반쪽시들음병균의 cellulose-growth-specific protein partial mRNA 유전자 염기서열을 이용하여 4개의 특이 프라이머 세트를 제작하였다. 최적 반응조건 및 시간은 60℃ 내외의 온도조건에서 60분 이내에서 가장 효율이 좋은 것으로 나타났다. 이 등온증폭 검출법은 4종의 토양전염성 병원균과 기주식물의 DNA에는 반응하지 않았다. 따라서 반쪽시들음병균 등온증폭법을 활용한다면 병원균의 감염 유무를 조기에 신속하게 진단할 수 있고, 반쪽시들음병을 효율적으로 모니터링하고 방제할 수 있을 것으로 기대한다.

• 식물병연구
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• 제13권1호
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• pp.15-19
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• 2007

2003년부터 2005년 사이 국화 주요 재배단지인 구미, 마산, 부산에서 국화의 잎이 시들며 갈색으로 말라 죽는 증상이 발생하였다. 시들고 황화된 잎은 병징이 진행됨에 따라 잎 가장자리로부터 마르며 피해증상은 시든 잎으로부터 위쪽으로 진행되며 식물체 전체에 피해를 주고 있었다. 초기 병징이 종종 식물체의 한쪽 면에서만 먼저 나타나기 때문에 "반쪽시들음병"이라고 불리는 특징을 가진다. 또한 유관속 폐쇄에 의한 일반적인 시들음병과는 달리 물관부 갈변을 확인할 수 없었으며 시든 잎의 잎자루가 달린 기부를 잘라 해부현미경으로 관찰한 결과 옅은 갈색으로 내부세포가 갈변되어 있는 것을 관찰할 수 있었다. 병든 잎의 잎자루 기부 조직으로부터 병원균을 분리하여 동정한 결과 균학적 특징과 병원성을 검정한 결과 Verticillium dahliae으로 동정되었다. 배양적 특징으로는 균총은 처음에는 흰색 내지 옅은 크림색을 나타내고 배양기간이 경과됨에 따라 검은색 소형균핵(microsclerotia) 을 많이 형성하였다. 분생포자의 모양은 원통형 내지 타원형이며 무색으로 크기가 $2.5{\sim}8.8{\times}2.0{\sim}3.8{\mu}m$이었으며, 균사생장은 $25^{\circ}C$에서 가장 좋았다. 이상과 같이 Verticillium dahliae에 의해 국화에 발생한 반쪽시들음병의 병징과 균학적 특징에 대한 연구결과를 보고한다.