Cankers are localized dead areas in the bark of stems, branches or twigs of many types of trees and shrubs, and are usually caused by fungi. We observed severe canker symptoms in oak trees located in Gyeongnam province in 2011. A total 31 trees were discovered with cankers of varied size, with an average of 48.5 x 15.2 cm. Black, half-rounded globular mound shaped stromata were associated with the cankers, and the asci of the fungi associated with the cankers were cylindrical shaped with their spore-bearing parts being up to 84 microm in length. The average fungal ascospores size was 7.59 x 4.23 microm. The internal transcribed spacer sequence for the canker causing fungus showed 99% similarity to the sequence of Annulohypoxylon truncatum. In this study, the isolated fungus was precisely described and then compared with fungi of similar taxa.
Fungi ; Quercus ; Trees

Aims: The effect of Quercus infectoria (QI) gall extract on the fungal expression of antioxidant defense enzymes of Candida albicans was studied in an effort to unravel its anti-fungal mechanism. Methodology and results: Minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and time kill assays were conducted to analyse the antifungal activity of the extract against C. albicans. Total protein profiles of C. albicans were determined by SDS-PAGE and real-time PCR was used to quantify the genes expression level of superoxide dismutase (SOD1), catalase (CAT1) and glutathione peroxidase (GPX3) following treatment with aqueous QI gall extract. The MIC and MFC values of the extract against C. albicans were 8 mg/mL and 16 mg/mL respectively. Fungistatic and fungicidal activities of the extract were observed after 24 h at 1× MIC and 2× MIC from the time-kill assay. A lower total protein bands density of extract-treated C. albicans was visualized when compared to the untreated cells at concentrations of 1× MIC and 2× MIC. A significant reduction in the expression of GPX3 (p 0.05). Conclusion, significance and impact of study In conclusion, QI gall extract exerted an anti-Candida activity and it is apparently effective in downregulating the gene expression of GPX3 in C. albicans. Of note, the present findings elucidated a preliminary mechanism associated with the organism’s survival resilience which represents a key target for the development of anti-Candida agents in future.
Quercus ; Candida albicans

Depending on the mode of nutrition exploitation, major fungal guilds are distinguished as ectomycorrhizal and saprotrophic fungi. It is generally known that diverse environmental factors influence fungal communities; however, it is unclear how fungal communities respond differently to environment factors depend on fungal guilds. In this study, we investigated basidiomycetes communities associated with Quercus mongolica using 454 pyrosequencing. We attempted to detect guild pattern (ectomycorrhizal or saprotrophic fungal communities) by comparing the influence of geography and source (root and surrounding soil). A total of 515 mOTUs were detected from root (321) and soil (394) of Q. mongolica at three sites of Mt. Jeombong in Inje County. We found that patterns of diversity and community structure were different depending on the guilds. In terms of alpha diversity, only ectomycorrhizal fungi showed significant differences between sources. In terms of community structure, however, geography significantly influenced the ectomycorrhizal community, while source appeared to have a greater influence on the saprotrophic community. Therefore, a guild-based view will help to elucidates novel features of the relationship between environmental factors and fungal communities.
Basidiomycota* ; Fungi ; Geography ; Quercus* ; Republic of Korea* ; Soil

In Korea, mass mortality of Quercus mongolica trees has become obvious since 2004. Raffaelea quercus-mongolicae is believed to be a causal fungus contributing the mortality. To evaluate the pathogenicity of the fungus to the trees, the fungus was multiple- and single-inoculated to the seedlings and twigs of the mature trees, respectively. In both the inoculations, the fungus was reisolated from more than 50% of inoculated twigs and seedlings. In the single inoculations, proportions of the transverse area of non-conductive sapwood at inoculation points and vertical lengths of discoloration expanded from the points were significantly different between the inoculation treatment and the control. In the multiple inoculations, no mortality was confirmed among the seedlings examined. These results showed that R. quercus-mongolicae can colonize sapwood, contribute to sapwood discoloration and disrupt sap flows around inoculation sites of Q. mongolica, although the pathogenicity of the fungus was not proven.
Colon ; Fungi ; Korea ; Mortality ; Quercus* ; Seedlings ; Trees ; Virulence

Present experiments were conducted to determine the possibility of artificial culture with various sawdust of P. gilvus. The pH value was 6.0 of oak sawdust, 6.5 of mulberry sawdust, 6.6 of elm sawdust, 6.3 of acacia sawdust and 6.1 of apple tree sawdust. Mycelial density on elm sawdust and acacia sawdust were lower than those of oak sawdust, and apple sawdust. Weight of fresh fruiting body showed that 179 g on oak tree, 227 g on oak sawdust, 21 g on elm tree, 76 g on elm sawdust, 106 g on apple tree, and 170 g on apple sawdust. Among them, the yield of oak substrates was the highest whereas acacia sawdust was the lowest, and it is concluded that the yields of sawdust substrates were higher than log substrates. P. gilvus grown on various sawdusts and logs used in this study have shown similar in anti-tumor activity against P388.
Acacia ; Fruit* ; Hydrogen-Ion Concentration ; Morus ; Quercus ; Trees ; Ulmus

Various types of ectomycorrihzal root were observed from the bases of the basidiocarps collected from the four different soils of WalAk Mt., JoRyeong Mt, MinJuJi Mt. and hills near Korea National University of Education; The dichotomous ectomycorrihzal roots were mainly found to be from the interactions of the Pinus roots with the basidiocarps of Boletus and Amanita species. The black single bat-like ectomycorrihzal roots with the darken rhizomorphic mycelia were mainly found to be from the interactions of the Quercus roots with the basidiocarps of Russula species. The pyramid and the monopodial-pinnate ectomycorrihzal roots were also found to be from the interactions of the Pinus and deciduous tree roots with the basidiocarps of Russula and Boletus species. The distinguished structures of the mantle and Hartig net in the cortex layers were observed to be from the roots related to the genus of Pinus in the anatomical sections. However, the aggregated (premeated) structures of mantle and Hartig net in the cortex layer were found to be in the black and bat-like ectomycorrihzal roots. The structures of cross section in the ectomycorrihzal roots, especially the roots related to the host-plants of Pinus, were observed to be different from those according to the fungal species of the basidiocarps collected. The ectomycorrihzal root not reported or confirmed by the anatomical sections were newly found to be from the bases of the basidocarps of Amanita castanopsidis, Boletus laetissimus, B. violaceofuscus, B. speciosus, Clitopilus prunulus, Leccinum rugosiceps, Russula. alboareolata, R. bella, Strobilomyces confusus, Tylropilus neofelleus, and T. plumbeoviolaceus. From the observations mentioned above, the various types of ectomycomhzal roots were speculated to be formed between the different host plants and the different species of basidiocarps.
Amanita ; Chungcheongbuk-do* ; Education ; Fruiting Bodies, Fungal ; Korea ; Pinus ; Quercus ; Soil ; Trees

The ambrosia beetle, Platypus koryoensis, is a serious pest of oak trees in Korea. In this study we investigated filamentous fungi present in the body of the beetle. Fourteen genera of filamentous fungi belonging to Ascomycota and Basidiomycota were isolated. Among the isolated fungi, some were able to produce wood degrading enzymes. This is first report of fungi associated with P. koryoensis.
Ambrosia ; Ascomycota ; Basidiomycota ; Beetles ; Fungi ; Insect Vectors ; Insects ; Korea ; Platypus ; Quercus ; Wood

The ambrosia beetle, Platypus koryoensis, is an economically important pest affecting oak trees in Korea. Candida kashinagacola was isolated from galleries of the beetle in oak wood and identified by analyses of morphology, physiological properties, and nucleotide sequence of the large subunit ribosomal DNA. This is the first report on Candida species associated with oak wilt disease vectored by the ambrosia beetle, Platypus koryoensis, in Korea.
Ambrosia ; Base Sequence ; Beetles ; Candida* ; Disease Vectors* ; DNA, Ribosomal ; Korea* ; Platypus* ; Quercus ; Wood

PURPOSE: Oak is the dominant tree species in Korea. Oak pollen has the highest sensitivity rate among all allergenic tree species in Korea. A deep neural network (DNN)-based estimation model was developed to determine the concentration of oak pollen and overcome the shortcomings of conventional regression models. METHODS: The DNN model proposed in this study utilized weather factors as the input and provided pollen concentrations as the output. Weather and pollen concentration data were used from 2007 to 2016 obtained from the Korea Meteorological Administration pollen observation network. Because it is difficult to prevent over-fitting and underestimation by using a DNN model alone, we developed a bootstrap aggregating-type ensemble model. Each of the 30 ensemble members was trained with random sampling at a fixed rate according to the pollen risk grade. To verify the effectiveness of the proposed model, we compared its performance with those of models of regression and support vector regression (SVR) under the same conditions, with respect to the prediction of pollen concentrations, risk levels, and season length. RESULTS: The mean absolute percentage error in the estimated pollen concentrations was 11.18%, 10.37%, and 5.04% for the regression, SVR and DNN models, respectively. The start of the pollen season was estimated to be 20, 22, and 6 days earlier than that predicted by the regression, SVR and DNN models, respectively. Similarly, the end of the pollen season was estimated to be 33, 20, and 9 days later that predicted by the regression, SVR and DNN models, respectively. CONCLUSIONS: Overall, the DNN model performed better than the other models. However, the prediction of peak pollen concentrations needs improvement. Improved observation quality with optimization of the DNN model will resolve this issue.
Korea ; Pollen ; Quercus ; Rhinitis, Allergic ; Rhinitis, Allergic, Seasonal ; Seasons ; Trees ; Weather

This study was carried out to investigate the possibility for seeds germination of Gastrodia elata using symbiotic fungi. Since seeds of G. elata are very small and lack an endosperm and other nutrients, their germination is difficult without requirement for external nutrients. Out of twenty six isolates collected from protocorms of G. elata and roots of native orchids inhabited in wild, two strains (H-2 and H-21) were observed to stimulate the seed germination of G. elata. The seed germination of G. elata was excellent on oak tree leaves medium. The optimal conditions for mycelial growth of symbiotic fungi were 25degrees C and pH 6.0, respectively. The mycelial growth of H-2 strain was excellent on YMA medium, while H-21 was poor on PDA medium. In case of carbon sources, the mycelial growth of H-2 and H-21 was good on media supplemented with glucose and dextrin, respectively. Calcium nitrate was good for mycelial growth of H-2 strain as a nitrogen sources, whereas urea was effective to H-21 strain.
Calcium ; Carbon ; Endosperm ; Fungi* ; Gastrodia* ; Germination* ; Glucose ; Hydrogen-Ion Concentration ; Nitrogen ; Quercus ; Urea