• Title/Summary/Keyword: white rot.

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Biological Control of White Rot in Apple Using Bacillus spp. (Bacillus spp.를 이용한 사과 겹무늬썩음병의 생물학적 방제)

  • Ha-Kyoung Lee;Jong-Hwan Shin;Seong-Chan Lee;You-Kyoung Han
    • Research in Plant Disease
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    • v.29 no.4
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    • pp.390-398
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    • 2023
  • Apple white rot, caused by Botryosphaeria dothidea, is one of the important diseases in Korea. B. dothidea can cause pre- and postharvest decay on apple fruit as well as canker and dieback of apple trees. In this study, we isolated bacteria from the trunk of apple trees and tested their antagonistic activity against B. dothidea. Five bacterial isolates (23-168, 23-169, 23-170, 23-172, and 23-173) were selected that were most effective at inhibiting the mycelial growth of the pathogens. The isolate 23-172 was identified as Bacillus amyloliquefaciens and four isolates 23-168, 23-169, 23-170, and 23-173 were identified as Bacillus velezensis by RNA polymerase beta subunit (rpoB) and DNA gyraseA subunit (gyrA) gene sequencing. All isolates showed strong antagonistic activity against B. dothidiea as well as Colletotrichum fructicola and Diaporthe eres. All isolates exhibited cellulolytic, proteolytic and phosphate solubilizing activities. In particular, two isolates 23-168, 23-169 were shown to significantly reduce the size of white rot lesions in pretreated apple fruits. These results will provide the basis for the development of a fungicide alternative for the control of white rot of apple.

First Report of Sclerotinia Rot Caused by Sclerotinia sclerotiorum on Some Vegetable Crops in Korea

  • Chang, Seog-Won;Kim, Sung-Kee
    • The Plant Pathology Journal
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    • v.19 no.2
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    • pp.79-84
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    • 2003
  • Sclerotinia rot occurred severely on some vegetable crops grown in Namyangju, Yangpyung, and Yangiu areas in Korea in 2001-2002. The crops infected with Scterotinia sp. were Adenophora remotiflora, Armoracia lapathfolia, Angelica acutiloba, Angelica archangelica, Anthriscus sylvestris, Aster tataricus, Beta vulgaris var. cicla, Brassica campestris var. marinosa, Brassica juncea var. laciniata, Chicholium intybus, Lactuca indica var. dracoglossa, Lactuca sativa var. oak-leaf, Petroselinum crispum, and Phyteuma japonicum. The fungus associated with the disease was identified as Sclerotinia sclerotiorum, based on the morphological characteristics of the pathogen. The symptoms were water-soaked spots that enlarged later and became a watery soft rot. Infected parts became yellow and then turned brown, followed by death of the whole plant. White mycelia developed on the upper petioles and leaves and on the soil where these plant parts lay. Then black sclerotia in variable size and shape formed from the mycelial mass. Pathogenicity of the fungus was proven by artificially inoculating each crop. This is the first report of Sclerotinia rot on the listed vegetable crops in Korea.

Mycological Characteristics and Pathogenicity of Fusarium oxysporum Schlecht. emend. Snyld. & Hans. Causing Stem Rot of Cactus (접목선인장 줄기썩음병균, Fusarium oxysporum Schlecth. emend. Snyd. & Hans.의 균학적 특성과 병원성)

  • 현익화;이상덕;이영희;허노열
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.463-466
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    • 1998
  • A Fusarium species was isolated from stems of cactus(Hylocereus trigonus) showing rot symptoms at Koyang, Kyonggi province in 1997. This pathogen was identified as Fusarium oxysporum based on mycological characteristics. The rot symptom appeared at the soil line and roughly circular lesions, 1∼3 mm in diameter, appeared on basal stems. The pathogen formed both microconidia and macroconidia. Microconidia were formed abundantly in false-heads on short monophialides, oval to kidney-shaped. Macroconidia were slightly sickle-shaped, 3∼5-septated with an attenuated apical cell and a foot-shaped basal cell. Colony color on PDA was white, peach or purple. Chlamydospores were formed abundantly on PDA. The pathogen was able to cause stem rot symptoms to cactus by wound inoculation as well as non-wound inoculation.

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Phylogenetic Classification of Antrodia and Related Genera Based on Ribosomal RNA Internal Transcribed Spacer Sequences

  • Kim, Seon-Young;Park, So-Yeon;Jung, Hack-Sung
    • Journal of Microbiology and Biotechnology
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    • v.11 no.3
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    • pp.475-481
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    • 2001
  • Sequences of ribosomal internal transcribed spaces (ITS) obtained from two Antrobia species and two related species were compared to investigate intrageneric and intergeneric phylogenetic relationships of Antrodia. The results showed that Antrodia species causing a brown rot in wood did not form a monophyletic clade and were separated into three distinct groups. Antrodia gossypina and A. vaillantii formed a clade having rhizomorphs as a homologous character. Antrodia serialis, A. sinuosa, and A. malicola formed a group together with Daedalea, Fomitopsis, and Postia species with brown rot habit. Antrodia xantha with a trimitic hyphal system and amyloid skeletal hyphae formed another distinct clade form other Antrodia species. The Antrodia species were separated from white rot genera such as Antrodiella, Diplomitoporus, Junghuhnia, and Steccherinum, indicating the phylogenetic importance of the rot type in the classification of the Polyporaceae.

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Fusarium oxysporum Causes Root Rot on Gastrodia elata in Korea: Morphological, Phylogenetic, and Pathogenicity Analyses

  • Sang-A Lee;Eun-Kyung Bae;Chanhoon An;Min-Jeong Kang;Eung-Jun Park
    • The Korean Journal of Mycology
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    • v.50 no.1
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    • pp.41-46
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    • 2022
  • Gastrodia elata infected with root rot disease was collected from cultivated G. elata fields in Gimcheon, Korea, in 2018. G. elata tuber surfaces exhibited root rot disease symptoms of dark-grey lesions and white fungal mycelial growth. The fungus was isolated from symptomatic tubers and cultured. Based on morphological characteristics and molecular analysis of the internal transcribed spacer region of ribosomal DNA and translation elongation factor 1-alpha, the isolated fungus was Fusarium oxysporum. This is the first report of root rot caused by F. oxysporum on G. elata tubers in Korea.

Biodegradation of Pentachlorophenol by Various White Rot Fungi (수질분해균(水質分解菌)에 의한 Pentachlorophenol의 미생물분해(微生物分解))

  • Choi, In-Gyu;Ahn, Sye-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.3
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    • pp.53-62
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    • 1998
  • In this research, 7 species of white rot fungi were used for determining the resistance against pentachlorophenol (PCP). Three fungi with good PCP resistance were selected for evaluating the biodegradability, and biodegradation mechanism by HPLC and GC/MS spectrometry. Among 7 fungi, there were significant differences on PCP resistance on 4 different PCP concentrations. In the concentrations of 50 and 100ppm ($\mu$g of PCP per g of 2% malt extract agar), most fungi were easily able to grow, and well suited to newly PCP-added condition, but in that of more than 250ppm, the mycelia growths of Ganoderma lucidum 20435, G. lucidum 20432, Pleurotus ostreatus, and Daldinia concentrica were significantly inhibited or even stopped by the addition of PCP to the culture. However, Trametes versicolor, Phanerochaete chrysosporium, and Inonotus cuticularis still kept growing at 250ppm, indicating the potential utilization of wood rot fungi to high concentrated PCP biodegradation. Particularly, P. chrysosporium even showed very rapid growth rate at more than 500ppm of PCP concentration. Three selected fungi based on the above results showed an excellent biodegradability against PCP. P. chrysosporium degraded PCP up to 84% on the first day of incubation, and during 7 days, most of added PCP were degraded. T. versicolor also showed more than 90% of biodegradability at 7th day, and even though the initial stage of degradation was very slow, I. cuticularis has been approached to 90% at 21 st day after incubation with dense growing pattern of mycelia. Therefore, the PCP biodegradability was definitely dependent on the rapid suitability of fungi to newly PCP-added condition. In addition, the PCP biodegradation by filtrates of P. chrysosporium, T. versicolor, and I. cuticularis was very minimal or limited, suggesting that the extracellular enzyme system may be not so significantly related to the PCP biodegradation. Among the biodegradation metabolites of PCP, the most abundant one was pentachloroanisole which resulted in a little weaker toxicity than PCP, and others were tetrachlorophenol, tetrachloro-hydroquinone, benzoic acid, and salicylic acid, suggesting that PCP may be biodegraded by several sequential reactions such as methylation, radical-induced oxidation, dechlorination, and hydroxylation.

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Environmental factors Associated with Disease Development of Garlic White Rot Caused by Two Species of Sclerotium (온도와 토양습도가 마늘 흑색썩음균핵병 발생에 미치는 영향)

  • Kim Yong-Ki;Kwon Mi-Kyung;Shim Hong-Sik;Kim Tack-Soo;Yeh Wan-Hae;Cho Weon-Dae;Choi In-Hu;Lee Seong-Chan;Ko Sug-Ju;Lee Yong-Hwan;Lee Chan-Jung
    • Research in Plant Disease
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    • v.11 no.2
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    • pp.128-134
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    • 2005
  • This study was conducted to elucidate effect of environmental factors on the development of white rot. In order to identify the causal agents causing white rot of Allium crops, we compared DNA profiles of a representative isolate, Sclerotium cepivorum, introduced from foreign country with Korean isolates using UP-PCR. As a result, Sclerotium isolates forming round-shaped sclerotia were identified as Sclerotium cepivorum pertaining in UP-PCR b group and Sclerotium isolates farming anamorphic-shaped sclerotia presumed to be a novel species of Sclerotium based on DNA profiles of UP-PCR. There was a big difference in DNA band pattern between two species of Sclerotium isolated in Korea. Electron micrographs of scanning electron microscope and transmission electron microscope showed morphological differences in sclerotial surface structure and rind layers between two species of Sclerotium. There were more wrinkles and pore spaces on sclerotial surface of Sclerotium sp. forming anamorphic-shaped sclerotia than that of Sclerotium cepivorum forming round-shaped sclerotia. Both of two white rot pathogens grew well at the temperature range of $10-25^{\circ}C$ with optimal temperature of $20^{\circ}C$. Sclerotia of the two pathogens were well formed at $20^{\circ}C$ and well germinated at the temperature range of $20-24^{\circ}C$, Effect of pre-incubation of sclerotia on destruction of sclerotial dormancy of two pathogens was evaluated through storing sclerotia under different temperature condition. The sclerotia of the two pathogens showed an increased capacity to germinate on potato dextroise agar when the sclerotia were incubated for 7 days at $10^{\circ}C$ after pre-treatment at $35^{\circ}C$ for 7 days. At that time, germination rate of Sclerotium sp. and 5. cepivorum was $100\%\;and\;70\%$, respectively. Flooding period and treatment temperature had an effect on sclerotial survival rate of the two pathogens. As flooding period and treatment temperature increased, sclerotial germination rate of the two pathogens decreased. It was confirmed that soil humidity played an important role on development of white rot. It was the highest disease incidence of garlic white rot when garlic were sown at potted soils infested with the two pathogens and adjusted soil humidity to $15\%$ (field moisture capacity, about -300 mb). As soil humidity increase or decrease based on $15\%$ of soil humidity, disease incidence decreased move and more.

Biodegradation and Saccharification of Wood Chips of Pinus strobus and Liriodendron tulipifera by White Rot Fungi

  • Hwang, Soon-Seok;Lee, Sung-Jae;Kim, Hee-Kyu;Ka, Jong-Ok;Kim, Kyu-Joong;Song, Hong-Gyu
    • Journal of Microbiology and Biotechnology
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    • v.18 no.11
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    • pp.1819-1825
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    • 2008
  • Degradation and glucose production from wood chips of white pine (Pinus strobus) and tulip tree (Liriodendron tulipifera) by several white rot fungi were investigated. The highest weight losses from 4 g of wood chips of P. strobus and L. tulipifera by the fungal degradation on yeast extract-malt extract-glucose agar medium were 38% of Irpex lacteus and 93.7% of Trametes versicolor MrP 1 after 90 days, respectively. When 4 g of wood chips of P. strobus and L. tulipifera biodegraded for 30 days were treated with cellulase, glucose was recovered at the highest values of 106 mg/g degraded wood by I. lacteus and 450 mg/g degraded wood by T. versicolor. The weight loss of 10 g of wood chip of L. tulipifera by T. versicolor on the nutrient non-added agar under the nonsterile conditions was 35% during 7 weeks of incubation, and the cumulative amount of glucose produced during this period was 239 mg without cellulase treatment. The activities of ligninolytic enzymes (lignin peroxidase, manganese peroxidase, and laccase) of fungi tested did not show a high correlation with degradation of the wood chips and subsequent glucose formation. These results suggest that the selection of proper wood species and fungal strain and optimization of glucose recovery are all necessary for the fungal pretreatment of woody biomass as a carbon substrate.