• Mycobiology
• /
• 제28권1호
• /
• pp.1-4
• /
• 2000

The section of Annulata under genus Hypoxylon is a member of the Xylariaceae which has ascomata with ostioles papillate ill a flattened disc. The isolates of Hypoxylon collected from the Tropic to the Temperate are compared with similar taxa and described. These isolations under Annulata section are illustrated with a light microscopy and a scanning electron microscopy. Hypoxylon archeri is newly recorded from Korea. A key to the species is also included.

• Mycobiology
• /
• 제28권1호
• /
• pp.5-10
• /
• 2000

The genus Hypoxylon is a member of the Xylariaceae which has brown to dark brown and pha- seoliform single cell ascospores with a conspicuous full germ slit. The isolates of Hypoxylon collected from England, Hong Kong and Korea are compared with similar taxa and described. These isolations under Hypoxylon section are detailed and illustrated, using light microscopy and scanning electron microscopy. Hypoxylon howeianum and H. rubiginosum are described and compared with former collection from Korea. A key to the species is also included.

• Mycobiology
• /
• 제45권3호
• /
• pp.129-138
• /
• 2017

In this study, we aimed to characterize fungal samples from necrotic lesions on collar regions observed in different sweetpotato growing regions during 2015 and 2016 in Korea. Sclerotia appeared on the root zone soil surface, and white dense mycelia were observed. At the later stages of infection, mother roots quickly rotted, and large areas of the plants were destroyed. The disease occurrence was monitored at 45 and 84 farms, and 11.8% and 6.8% of the land areas were found to be infected in 2015 and 2016, respectively. Fungi were isolated from disease samples, and 36 strains were preserved. Based on the cultural and morphological characteristics of colonies, the isolates resembled the reference strain of Sclerotium rolfsii. Representative strains were identified as S. rolfsii (teleomorph: Athelia rolfsii) based on phylogenetic analysis of the internal transcribed spacer and large subunit genes along with morphological observations. To test the pathogenicity, sweetpotato storage roots were inoculated with different S. rolfsii strains. 'Yulmi' variety displayed the highest disease incidence, whereas 'Pungwonmi' resulted in the least. These findings suggested that morphological characteristics and molecular phylogenetic analysis were useful for identification of S. rolfsii.

• The Plant Pathology Journal
• /
• 제18권4호
• /
• pp.228-230
• /
• 2002

Anthracnose symptoms caused by Glomerella cingulata were observed on leaves and stems of gardenia in Sunchon, Jeonnam in Korea in 2000. Symptoms on infected plants typically appeared as irregularly circular, dark-brown ring spots and water-soaked brown lesions. Based on cultural and morphological characteristics, the fungus (G-00-03 isolate) from the diseased plants was identified as Colletotrichum gloeosporioides, and its teleomorph stage was Glomerella cingulata. Healthy gardenia artificially inoculated with fungal spores showed anthracnose symptom 7 days after inoculation. This is the first report of gardenia anthracnose caused by Glomerella cingulata in Korea.

• Mycobiology
• /
• 제30권3호
• /
• pp.117-127
• /
• 2002

Cleistothecial development in Aspergillus nidulans(teleomorph, Emericella nidulans) was examined with the transmission electron microscopy. Cleistothecial initial was a small coiled lump of cells, ca. 6 ${\mu}m$ in diameter, which was consisted of a slightly swollen core with a short "tail" hypha. Initials were wrapped with a loose layer of hyphae. Core cells of cleistothecial initials were broad and multinucleated at first, then formed dikaryotic ascogenous cells, followed by post-meiotic tetra-nucleate or octa-nucleate protoasci and finally mature ascospores. Croziers were formed early during cleistothecium development. The peridial layer of mature cleistothecia was derived from the wrapping hyphae which originally invested the young cleistothecium. Completion of peridial layers development was associated with the depositing of a non-enzyme reactive material around peridial cells. $H\ddot{u}lle$ cell formation during the cleistothecial development appeared to be somewhat coordinated with the developmental stages of cleistothecium.

• The Plant Pathology Journal
• /
• 제17권4호
• /
• pp.236-241
• /
• 2001

Serve outbreaks of anthracnose were observed on perilla plants grown in greenhouses and open fields in several locations in Korea during the disease survey from 1997 to 2000. A total of 53 isolates of Colletotrichum spp. and Glomerella sp. was obtained from diseased perilla plants and identified based on their morphological and cultural characteristics. Forty isolates were identified as Colletotrichum gloeosporioides, three isolates as C. coccodes, five isolates as C. dematium, and the other five isolates as Glomerella cingulata, the teleomorph of C. gloeosporioides. All isolates of C. gloeosporioides tested by artificial inoculation were strongly virulent on perilla plants, but isolates of the other species were weakly or not virulent. Anthracnose symptoms induced on the perilla plants by artificial inoculation with the isolates of C. gloeosporioides were similar to those observed in the fields. This study revealed that C. gloeosporioides is the main causal fungus of perilla anthracnose.

• The Plant Pathology Journal
• /
• 제25권3호
• /
• pp.299-301
• /
• 2009

Powdery mildew symptoms were frequently on plants of goat's-beard (Aruncus dioicus var. kamtschaticus) found cultivated in the island Ulleungdo in June 2008. The symptoms appeared as powdery mycelial colonies and dark brown cleistothecia on leaves, petioles, stems and budding flowers of the plant. Incidence of the disease was as high as 50-80% in the goat's-beard fields. Specimens of the diseased plants were collected and examined for morphological characteristics of the causal fungus. On the basis of morphological characteristics of the conidial stage and the teleomorph, the fungus was identified as Podosphaera ferruginea. This is the first report of goat's-beard powdery mildew caused by Podosphaera ferruginea in Korea.

• Mycobiology
• /
• 제37권4호
• /
• pp.310-312
• /
• 2009

A total of 82 isolates of Colletotrichum species were obtained from anthracnose symptoms of highbush blueberry trees grown in the Gochang area of Korea during a disease survey in 2008. Out of the isolates, 75 were identified as Colletotrichum gloeosporioides and the others as C. acutatum based on their morphological and cultural characteristics. Twenty six of C. gloeosporioides isolates produced their teleomorph Glomerella cingulata in PDA culture. Three isolates of each C. gloeosporioides and C. acutatum caused anthracnose symptoms on the leaves by artificial inoculation, which were similar to what was observed in the orchards. Previously in Korea, only C. gloeosporioides has been reported as causing anthracnose in blueberries. This is the first report that C. acutatum causes anthracnose in the highbush blueberry in Korea.

• 한국균학회지
• /
• 제44권4호
• /
• pp.377-381
• /
• 2016

2015년 5월, 경상북도 의성군 소재 매실과원에서 비정상적인 엽화증상이 매실나무에서 관찰되었다. 관찰된 엽화증상에서는 외부에 주황색의 돌기가 관찰되었고, 실체현미경으로 관찰한 결과 녹포자퇴로 확인되었다. 자세한 형태를 관찰하기 위해 광학현미경과 주사전자현미경으로 관찰한 결과, 녹포자는 구형, 타원형 또는 난형이었고, 약 $22.8{\sim}35.6{\times}19.8{\sim}36.8{\mu}m$ 크기를 가지면서 표면은 무사마귀형으로 관찰되었다. 녹포자의 정확한 동정과 계통학적 유연관계 분석을 위하여, 18S rDNA와 large subunit rDNA 영역을 증폭시킨 후 염기서열을 분석하고 계통학적 유연관계를 분석하였다. 그 결과, 매실나무의 엽화증상에서 관찰된 병원균은 일본에서 분리된 Caeoma makinoi (Teleomorph: B. smilacis) 균주와 100% 일치하는 것으로 확인되었다. 따라서 본 연구에서는 국내 매실나무에서 엽화증상을 일으키는 녹병균을 Caeoma makinoi로 보고하고, 위 병원균에 의한 매실나무 엽화증상을 매실꽃눈녹병으로 제안하고자 한다.

• The Plant Pathology Journal
• /
• 제24권1호
• /
• pp.1-7
• /
• 2008

Fusarium verticillioides (teleomorph Gibberella moniliformis) is associated with maize worldwide causing ear rot and stalk rot, and produces fumonisins, a group of mycotoxins detrimental to humans and animals. While research tools are available, our understanding of the molecular mechanisms associated with fungal virulence and fumonisin biosynthesis in F. verticillioides is still limited. One of the restraints that hampers F. verticillioides gene characterization is the fact that homologous recombination (HR) frequency is very low (<2%). Screening for a true gene knock-out mutant is a laborious process due to a high number of ectopic integrations. In this study, we generated a F. verticillioides mutant (SF41) deleted for FvKU70, a gene directly responsible for non-homologous end-joining mechanism, with the aim of improving HR frequency. Here, we demonstrate that FvKU70 deletion does not impact key Fverticillioides phenotypes, e.g., development, secondary metabolism, and virulence, while dramatically improving HR frequency. Significantly, we also confirmed that a high percentage (>85%) of the HR mutant strains harbor a desired mutation with no additional copy of the mutant allele inserted in the genome. We conclude that SF41 is suitable for use as a type strain when performing high-throughput gene function studies in F. verticillioides.