• Research in Plant Disease
• /
• v.8 no.4
• /
• pp.215-219
• /
• 2002

Fruit rot of pomegranate (Punica granatum) caused by Coniella granati were observed in several farmer's fields in Gwangdo-myon, Tongyeong City, Gyeongnam Province, Korea. The symptoms occurred on fruit with rotting then eventually dropping and mummification. The colony color of causal fungus was whitish on potato dextrose agar. Conidia were single celled, pale brown or olive in color at maturity, straight or slightly curved fusiform in shape, and were 10.3~17.4$\times$2.8~4.0 ${\mu}{\textrm}{m}$ in size. Conidiogenous cell were hyaline, branched only at the base aseptate, elongate, phialidic, enteroblastic and 12.4~1.4$\times$2.8~3.6 ${\mu}{\textrm}{m}$ in size. Pycnidia were black in color and globose in shape and 124.6~228.4 ${\mu}{\textrm}{m}$ in size. Optimum temperature for mycelial growth was $25^{\circ}C$. On the basis of mycological characteristics and pathogenecity test on host plants, the fungus was identified as Coniella granati. This is the first report on the fruit rot of pomegranate caused by Coniella granati in Korea.

• Research in Plant Disease
• /
• v.16 no.1
• /
• pp.90-93
• /
• 2010

Sclerotinia rot occurred sporadically on the stems and leaves of Astragalus sinicus in the farmers fields at Goseong-gun, Gyeongnam province in Korea. The infected plants showed the typical symptoms: watersoaked, wilt, rot, blight and eventual death. The colony of the isolated fungus on potato-dextrose agar (PDA) was white to faintly gray color. Sclerotia formed on the PDA were globose in shape, black in color and $2{\sim}14{\times}2{\sim}7mm$ in size. The optimum temperature for mycelial growth and sclerotium formation was at $20^{\circ}C$ on PDA. Apothecia formed on PDA were globose~disk in shape and 3~8 mm in size. Asci were cylindrical in shape and $145{\sim}210{\times}10{\sim}12{\mu}m$ in size. Ascospores were ellipsoid and $10{\sim}14{\times}6{\sim}7{\mu}m$ in size. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Sclerotinia trifoliorum Eriksson. This is the first report on sclerotinia rot of A. sinicus caused by Strifoliorum Eriksson in Korea.

• The Plant Pathology Journal
• /
• v.20 no.1
• /
• pp.58-62
• /
• 2004

White root rot of wild white clover (Trifoliorum repens) caused by isolate BWC98-105 has been first reported in Korea. Typical symptoms on root include water-soaked and dark-brown rot, resulting in complete blight of the whole plant. The fungus grew well at $20-28^{\circ}C$ and produced abundant sclerotia at 10-15 days after full mycelial growth on potato dextrose agar. Sclerotia were brown to dark-brown in color and 1-3 mm in length. When white clover plants were inoculated with mycelial suspension ($10^5$ cfu/ml) of isolate BWC98-105, the plant shoots were killed within 4-6 days and the roots were completely blighted. Sclerotia were also formed on the surface of the root covered with whitish mycelia within 10-15 days in the field. All nine isolates developed high incidences of white root rot disease on white clover seedlings, of which the symptoms were similar to those observed in the fields. Hence, their pathogenicity was confirmed on white clover. The infection rate of the fungal isolates varied from 78.5% to 95.2%, among which BWC98-105 was the most virulent isolate. The weeding efficacy of the fungus was maintained until the following year, leading to a significant reduction of reshooting. The fungus was specifically parasitic to white clover, but not to four lawn species including zoysiagrass (Zoysia japonica) under greenhouse test. The fungus also had no response to some Gramineae species including rice, but caused little damage to five species of Leguminosae.

• Weed & Turfgrass Science
• /
• v.2 no.3
• /
• pp.306-311
• /
• 2013

Pythium blight occurred by Pythium aphanidermatum on chewing fescue cv. "Jamestowm II" from early June, 2010 and 2011 at the test field in Daegu University in Gyeongbuk Province, Korea. Disease symptoms on the turfgrass were leaf blights dying from the leaf tip and root rot, which appeared patches of brown to dark brown color or gray brown color in the field. The pathogens (40-1 isolate) of Pythium blight was isolated from the diseased leaf and crown tissue and cultured on potato-dextrose agar (PDA) for identification. Lobulate sporangia were inflated, complex structures, and filamentous sporangia were usually indistinguishable from vegetative hyphae. Sequences of ribosomal RNA gene of the fungus were homologous with similarity of 100% to those of P. aphanidermatum isolates in GenBank database. Pathogenicity was also confirmed on the chewing fescue, creeping betgrass and Kentucky bluegrass by Koch's postulates. This is the first report of Pythium blight on chewing fescue caused by P. aphanidermatum in Korea.

• Korean Journal Plant Pathology
• /
• v.14 no.6
• /
• pp.646-650
• /
• 1998

Mycological characteristics of Phytophthora nicotianae var. nicotianae SPC10 (A1 type) causing Phytophthora rot of strawberry and the resistances of 11 strawberry cultivars against the pathogen were examined. Optimum temperature for the mycelial growth of the pathogen was obtained in the range of 30~35$^{\circ}C$, and the growth was completely stopped under 13$^{\circ}C$ or over 42$^{\circ}C$. Aerial mycelia were abundant on oatmeal agar (OMA), V-8 juice agar (V8A) and lima bean agar (LBA) medium, although there were slight differences, however, on cornmeal agar (CMA) medium, it was a shape of stellate without aerial mycelia. The colony shape on potato dextrose agar (PDA) medium was rough and irregular whereas the mycelial growth was slow, and some aerial mycelia were only produced in the middle of PDA medium. Optimum temperature for sporangial formation was 3$0^{\circ}C$, and zoospores were mostly released at $25^{\circ}C$ from the sporangia. Sporangia were more produced in C/Z solution with pH 5. 0~6.$0^{\circ}C$ than sterilized distilled water (DSW) and distilled water (DW), and zoospores were also released much more than other solutions. Eleven strawberry cultivars such as Reiko, Hokowase, Eyeberry, Akaneko, Sistakara, Toyonoka, Nyoho, Sulhong, Suhong, Myhong and Wonkyo #3104 revealed the disease incidence up to 88.9~100% by the leaf inoculation with mycelial disk. However, Nyoho and Suhong showed higher level of resistance against the pathogen by root inoculation.

• Research in Plant Disease
• /
• v.11 no.2
• /
• pp.173-178
• /
• 2005

Ampelomyces quisqualis 94013 (AQ94013), a hyperparasite, was selected as an effective biological control agent against cucumber powdery mildew. Optimal temperature for mycelial growth of AQ94013 was $26^{\circ}C$, and the optimal pH was 6.5. Conidia of AQ94013 were more Produced on potato dextrose agar (PDA) in darkness than under alternating cycles of 12 hr fluorescent light and 12 hr darkness. Temperature range for spore germination of the fungus was $10\~35^{\circ}C$, and optimal temperature was $20^{\circ}C$. Conidial germination of the fungus began 8 hr after incubation at $24^{\circ}C$. Germination rate of conidia at concentration of $5{\times}10^5\;spores/ml\;and\;5{\times}10^6\;spores/ml$ was higher than at concentration of $5{\times}10^7\;spores/ml$. The best source of carbon and nitrogen for mycelial growth of the fungus were dextrin and neopeptone, respectively.

• The Plant Pathology Journal
• /
• v.16 no.6
• /
• pp.321-324
• /
• 2000

season of 2000. The disease infection usually started from flower, peduncle and young fruits, then moved to flower stalk, stem and leaves. At first, the lesions started with water-soaked, rapidly softened, and then the area gradually expanded. In severely affected film house, the rate of infected fruits reached to 28.6%. Numerous sporangiospores were formed on the diseased fruits, flower stalk, stem and leaves. Most of the sporangiospores were appeare to be rapidly dispersed in the air. The mycelia grew on the surface of host and formed stolons. Colonies on potato dextrose agar were cottony at first brownish black at maturity. Sporangia were 125.3${\times}$294.2 ${\mu}$m. globose or sub-globose with somewhat flattened base. White at first the black, many spored, and are never overhanging. Sporangiophores were 2.7-6.8${\times}$12.9-33.9 ${\mu}$m, smooth-walled, non-septate, light brown, simple, long, arising in groups of 3-5 from stolons opposite rhizoids. Sporangiophores were 8.6-21.1${\times}$6.41-1.7 ${\mu}$m, irregular, round, oval, elongate, angular and brownish-black streaked. Columella were 63.8${\times}$140.4 ${\mu}$m. brownish gray, umberella-shaped when dehisced. The causal organism was identified as Rhizopus stolonifer Lind on the basis of the morphological characteristics of the fungus. Rhizopus soft rot on squash (Cucurbita moschata) caused by the fungi has not been previously reported in Korea.

• Research in Plant Disease
• /
• v.15 no.2
• /
• pp.127-129
• /
• 2009

Gray mold caused by Botrytis cinerea occurred on Astragalus sinicus in an experimetal rice field of Gyeongsangnam-do Agricultural Research and Extension Services in Korea from 2008 to 2009. The symptoms appeared on the leaves, petiole and stems of infected plants. and then started with water-soaked, rotted and eventually died blight on plants. The colony were grayish brown and the optimum temperature for sclerotial formation was $20^{\circ}C$ on potato dextrose agar. The conidia were one celled, mostly ellipsoid or ovoid in shape, and were colorless or pale brown in color. The conidia were $7{\sim}16{\times}5{\sim}10{\mu}m$ in size and conidiophores were $14{\sim}28{\mu}m$ in length. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Botrytis cinerea Persoon: Fries.

• The Plant Pathology Journal
• /
• v.29 no.3
• /
• pp.274-284
• /
• 2013

The incidence of Broad bean wilt virus 2 (BBWV2) on red pepper was investigated using the samples obtained from 24 areas of 8 provinces in Korea. Two hundred and five samples (79%) out of 260 collected samples were found to be infected with BBWV2. While the single infection rate of BBWV2 was 21.5%, the co-infection rate of BBWV2 with Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus and/or Potato virus Y was 78.5%. To characterize the genetic diversity of BBWV2 Korean isolates, 7 isolates were fully sequenced and analyzed. Phylogenetic analyses revealed that BBWV2 isolates could be divided largely into two groups as Group I and Group II. Based on the partial sequence analyses, 153 selected BBWV2 isolates were subgrouped into GS-I (21.6%), GS-II (3.9%) and GS-III (56.9%). BBWV2 GS-III, which was predominant in Korea, appears to be a new combination between Group I RNA-1 and Group II RNA-2. Viral disease incidence of BBWV2 on red pepper was under 2% before 2004. However, the incidence was increased abruptly to 41.3% in 2005, 58.2% in 2006 and 79% in 2007. These rapid increases might be related with the emergence of new combinations between BBWV2 groups.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.21 no.1
• /
• pp.48-53
• /
• 2010

Backgraound and Objectives : The voice change can occur in acute epiglottitis or peritonsillar abscess, and the labelings of both changes as a "muffled voice" or "hot potato voice", The aim of this study was to investigate the difference of changes in acoustic feature of voice before and after treatment in patients with acute epiglottitis or peritonsillar abscess. Subjects and Method: 13 patients with acute epiglottitis and 12 patients with peritonsillar abscess were enrolled in the study. Acoustic analysis on sustained Korean vowels /${\alpha}$/, /u/ and /i/ were performed before and after treatment. Results: In patients with acute epiglottitis, the first formant frequency (F1) of /${\alpha}$/ was increased, and the second frequency (F2) of /i/ was decreased. In patients with peritonsillar abscess, F1 and F2 of /${\alpha}$/ were decreased. F1 of /i/ and /u/ were increased, while F2 were decreased. Conclusion : The anatomical and functional changes of oropharynx and larynx by acute epiglottitis and peritonsillar abscess can cause different change in resonance and speech quality. We suggest that these changes could be the cause of 'muffled vocie' in patients of acute epiglottitis or peritonsillar abscess, but different characteristics of phonation in each disease should be distinguished.