• Research in Plant Disease
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• v.19 no.3
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• pp.229-232
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• 2013

Sclerotium rot of cucumber (Cucumis sativus L.) occurred at the experimental field of Gyeongsangnam-do Agricultural Research and Extension Services in July 2012. The typical symptoms included wilt, rot, and water-soaking on stems and fruits and severely infected plants eventually died. White mycelial mats spread over lesions, and then sclerotia were formed on fruit and near soil line. The sclerotia were globoid in shape, white to brown in color and 1-3 mm in size and the hyphal width was 4-8 ${\mu}m$. The optimum temperature for mycelial growth and sclerotia formation on PDA was $30^{\circ}C$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. For further identification, the complete internal transcribed spacer (ITS) rDNA region was amplified and sequenced. On the basis of mycological characteristics, ITS rDNA region comparison, and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of sclerotium rot on cucumber caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.27 no.3
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• pp.115-119
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• 2021

Sclerotinia rot was occurred on the leaf and stem of Peucedanum japonicum Thunb. in greenhouse field of Pohang city of Gyeongbuk province in Korea. The typical symptom of the disease was light brown spot and tipburn on infected leaves. The colony of the isolated fungus was white to light gray in color. Asci were cylindrical shape and 75-240×5.9-17.3 ㎛ in size. Apothecia were cup-shaped with numerous asci and 0.5-0.9 cm in size. Ascospores were aseptate and ellipsoid in shape, and 8.4-10.7×4.8-5.8 ㎛ in size. Sclerotia formed on the plants and potato dextrose agar medium were globose to irregular in shape and black in color. Partial sequencing of rDNA of this isolate showed that it was 100% consistent with that of Sclerotinia sclerotiorum. It was confirmed that the same lesion was formed by reinoculating this pathogen on a healthy P. japonicum Thunb. and the same strain was isolated. This is the first report on the Sclerotinia rot of P. japonicum Thunb. caused by S. sclerotiorum in Korea.

• Journal of Forest and Environmental Science
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• v.36 no.3
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• pp.225-232
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• 2020

Chemical modification of wood is an effective method to enhance the biological durability of wood with no toxic effect on the environment. In this study, wood of Triplochiton scleroxylon was modified using acetylation techniques. A total of one hundred wood blocks, (each 20×20×60 mm) obtained from a 22-year old T. scleroxylon tree were conditioned and acetylated at 120℃ in a bioreactor containing acetic anhydride for 60, 120, 180, 240 and 300 minutes. The percentage weight gain of acetylated wood was determined. The untreated (control) and treated blocks were exposed to Pleurotus ostreatus (white rot fungus) and Fibroporia vaillanti (brown rot fungus) after which moisture content (MC) and weight loss (WL) was monitored for 16 weeks. Data were analysed using descriptive and inferential statistics at p<0.05 level of significance. The percentage weight gain of acetylated wood samples increased with time from 10.4% (60 minutes) to 22.7% (300 minutes). MC of untreated blocks inoculated with Pleurotus ostreatus was significantly higher than those of Fibroporia vaillantii after 16 weeks exposure. There was no significant difference in the MC of the of the acetylated samples for the two fungi after 300 minutes reaction time. The WL of untreated blocks inoculated with Fibroporia vaillantii was higher than those of Pleurotus ostreatus, however, the two fungi showed no significant difference in the WL for the acetylated samples after 16 weeks exposure. Acetylation prevents moisture absorption and inhibition of fungi growth in acetylated wood compared to untreated wood, thereby enhancing the durability of Triplochiton scleroxylon.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.322-329
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• 2017

As a result of contemporary environmental concerns, a number of studies from plants' tissues as one of the alternatives to conventional chemicals are increasingly investigated. In tandem with these trends, Lagenaria breviflora (LB) fruit, reputed as antiviral and depilatory agents in the Yoruba folkloric medicine was examined on Vitex doniana wood to ascertain its antifungal activity. Fungicides of 25%, 50%, 75%, and 100% LB fruits formulations (concentrations) were developed through simple one-step mechanical-forming process, including control. In this study, the yield, the chemical compositions, the absorption capacity of the fungicides and wood weight losses (WWL) analysis were evaluated to investigate the antifungal activity of LB fruit on wood. The fruit extract yielded 35.4% of fresh juice weight. LB fruits contained total: alkaloids ($8.78{\pm}0.21mg/mL$), flavonoids ($2.01{\pm}0.02mg/mL$), phenol ($7.42{\pm}0.09mg/mL$), saponins ($11.00{\pm}0.10mg/mL$) and tannins ($5.47{\pm}0.05mg/mL$) contents. All the formulations provided effective protection against the tested wood fungi compared to control. Interestingly, the antifungal activity of 50% and 25% formulations of 6.8% WWL and 9.9% WWL satisfied the excellent fungal resistance class description against white rot fungus (Ganoderma lucidum) and brown rot fungus (Fibroporia vaillantii), respectively according to ASTM D 2017. These results thus, support LB fruit as a strong potential source of natural antifungals for industrial wood production.

• The Plant Pathology Journal
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• v.19 no.4
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• pp.203-204
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• 2003

Decayed samples of marketed mungbean sprout were collected from Sacheon, Suncheon, and Dangjin cities in Korea. Initial symptom on hypocotyls was dark-brown diamond speck, which developed into enlarged sunken brownish-black spot with irregular margin, followed by softening yellowish decay. Brown speck on cotyledon further developed into irregular lesions. This study isolated the fungus Colletotrichum sp. The fungal colony was pale orange, which turned greenish gray after 1 week at $25^{\circ}C$. Colony of reverse side in a petri dish was pink. Neither conidiomata nor setae were present in the culture. Typical fusiform conidia sized 7.5-15.0$\times$2.5-2.9 $\mu\textrm$were hyaline, aseptate, smooth, and had salmon color in mass. Conidiogenous cells were phialidic, hyaline, smooth, and cylindrical with terminal distinct collarette. Basedon these mycological characteristics, the casual organism was identified as Colletotrichum acutatum. This is first report of Colletotrichum acutatum in Korea.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.305-307
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• 2001

In March 2000, gray mold was found on day lily (Hemerocallis fulva L.) in Korea. Among the symptoms observed was blight or early rot with chlorotic halo of the leaves. All the isolates obtained from the lesions of the diseased plant parts were identified as Botrytis elliptica, based on the morphological characteristics of conidia. Conidia that formed on conidiogenous cells were not in chains, hyaline to pale brown, unicellular, ellipsoidal to obovate with a single hilum at the base, entirely verruculose, and 21-31 x 12-$23\mu\textrm{m}$ in size. Pathogenicity of the fungus was established by artificial inoculation on day lily plants. This is the first record of gray mold on day lily caused by B. elliptica in Korea.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.880-889
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• 2016

To evaluate the resistance of wood to decay caused by fungi, sapwood and heartwood of red pine (Pinus densiflora) and sapwood and heartwood of larch (Larix kaempferi) were conducted. Wood samples were immersed for 96 h in pyroligneous liquor. Then, the brown-rot fungus, Fomitopsis palustris, was used to examine the decay resistance of red pine and larch. Weight and density of wood from the all conditions increased after immersion treatment. Weight loss after decay resistance test was also dropped with a immersion treatment. The lowest weight loss indicated at immersion-treated heartwood of larch. Immersion treatment using pyroligneous liquor effectively increased the resistance of wood to decay caused by fungi.

• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.367-370
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• 1998

Monilina fructicola, the brown rot fungus of stone fruits, was isolated from overwintering mummies and peduncles on peach trees from February to March, 1998. The resistant population of these isolates to benzimidazole (benomyl, carbendazim and thiophanate-methyl) and dicarboximide (iprodione, vinclozolin and procymidone) was examined. Among 417 isolates, the incidence of isolates resistant to benomyl, carbendazim, and thiophanate-methyl were 45 (10.8%), 47 (11.3%), and 46 (11.0%), respectively. Forty two (10.0%) isolates showed cross-resistance to benzimidazole fungicides. On the other hand, the resistant isolates against iprodione, vinclozolin and procymidone were 186 (44.6%), 1 (0.2%) and 150 (36.0%), respectively. Among the isolates, 116 (27.8%) showed cross-resistance to iprodione and procymidone. Moreover, 27 (6.5%) of 417 isolates showed double-resistance to both benzimidazole (benomyl) and dicarboximide (iprodione).

• Journal of Ginseng Research
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• v.25 no.3
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• pp.136-140
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• 2001

Effects of incubation temperature and pH on chlamydospore germination of Cylindrocarpon destrcutans (isolate CY-9802) causing root rot of Panax ginseng were studied. Germination rate of the chlamydospores on Czapek solution agar(CSA) was higher than on potato dextrose agar(PDA) at the incubation temperatures tested. The chlamydospores were able to be germinated at range of 5$\^{C}$ to 30$\^{C}$ after 48 hours incubation on CSA. Germination rate was 53.2∼6.27% at range of 15$\^{C}$ to 25$\^{C}$, and the optimum temperature was 20$\^{C}$, whereas they were very low at 30$\^{C}$ on PDA. Germination rate was 43.6% to 47.9% at range of 10$\^{C}$ to 20$\^{C}$, and the optimum temperature was 20$\^{C}$ as well. They were able to be germinated at pH of 5.2 to 8.1 on CSA and 5.2 to 7.2 on PDA. Optimum pHs for the germination on CSA and PDA were from 6.4 to 8.2 and from 5.2 to 6.0, respectively. Mycelial color of the fungus on CSA was pale brown at pH from 5.2 to 6.0 and white from pH 6.4 to 8.1, while it was typical dark brown ar range of pH 5.2 to 7.1 and brown at pH 7.2 on PDA after 21 days incubation.

• Research in Plant Disease
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• v.10 no.4
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• pp.345-348
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• 2004

Pink rot of Palm was occurred at Yeuju area in 2001 and 2003. Infected plants showed rotting at the leaf-stock bases and killing of the terminal bud. The first symptoms are dark brown necrotic areas on the stem. Bases of infected frond may be covered with pink spores and the spots produced oozing gum pockets. Oozing lesions occur on the stems, and leaves turn brown and droop. The causal agent were isolated from salmon-pink spores sporulating on the leaf sheaths and necrotic stem tissues. Pathogen were isolated from freshly infected tissues were identified as Gliocladium vermoseni based on mycological characteristics. Fungus were grown plenty on PDA culture. Temperature for mycelial grown was tested at 5 to $40^{\circ}C$ and optimal temperature was $25^{\circ}C$ and was not nearly grew at temperature above $35^{\circ}C$. Artificial pathogenicity were tested on 9 species of Palm family in the wound inoculation and symptoms showed similar to those observed in the field. This is the first report on pink rot of palm in Korea.