• Mycobiology
• /
• v.39 no.4
• /
• pp.303-305
• /
• 2011

One rare and interesting species collected from Gyeryong-san, Chungnam Province is described and illustrated in detail. The species "Tectella patellaris (Fr.) Murr." and genus "Tectella Earle" is a first record for Korean fungal flora. Specimens cited here have been deposited in the Herbarium Conservation Center of National Academy of Agricultural Sciences.

• Journal of The Korean Association For Science Education
• /
• v.24 no.2
• /
• pp.309-319
• /
• 2004

The purpose of this study is to investigate middle school students' perceptions of private academy science education and of school science education in order to promote school science education. 180 middle school students who were taking a science class at a private academy were participated, and the short form of Classroom Environment Scale was implemented for the study. The results showed that the students went to an academy for supplementing school science or for getting a better grade in school. Some students, however, have different reason to go to an academy; they were kinds of silence-learners or received-learners rather than constructed-learners. That is, they didn't know how to and what to study. Students didn't have an opportunity to think scientifically and creatively from both academy and school science classes. They studied harder in science class at private academy than at school. Some students felt more favorable to and comfortable with academy teachers compare to school science teachers.

• Mycobiology
• /
• v.50 no.5
• /
• pp.389-398
• /
• 2022

Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC₅₀ value of lower than 10 ㎍/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anticancer compound.

• Journal of Biosystems Engineering
• /
• v.36 no.2
• /
• pp.140-146
• /
• 2011

This study was performed to develop a rapid test kit for pathogenic Salmonella in various samples. The rapid detection kit has been fabricated based on nitrocellulose lateral-flow strip. Colloidal gold and biotin conjugated Salmonella antibodies were used as a tag and a receptor, respectively. Manually spotted Salmonella antibody and Neutravidin on nitrocellulose membrane were used as test and control lines, respectively. Feasibility of the rapid kit to detect Salmonella typhimurium in samples were evaluated. The intensity of the color of the test line started to increase with the samples in which higher concentration of the cells were contained. The sensitivity of the sensor was $10^6$ cfu/mL Salmonella spiked in PBS. Also, the rapid test kit could detect $10^6$ cfu/mL of Salmonella in chicken meat extract.

• Research in Plant Disease
• /
• v.17 no.2
• /
• pp.232-234
• /
• 2011

During survey of postharvest diseases of vegetables in the middle region of Korea in 2003, 2004 and 2005, new disease symptoms showing watery rot and soft rot were observed. In this study, the disease causal agents were identified as Geotrichum candidum, and their host range and pathogenicity were investigated. G. candidum isolated had wide host range and strong pathogenicity against carrot, cucumber, tomato and pumpkin. The disease occurrence on several vegetables that G. candidum can be a serious threat to stable production of fresh vegetable.

• Journal of Plant Biotechnology
• /
• v.37 no.2
• /
• pp.205-211
• /
• 2010

Yield productivity of staple crops must be increased at least 50% by 2050, in order to feed the world population which is expected to reach 90 billions. Photosynthetic carbon assimilation and carbohydrate metabolism leading to the production of starch would be the final frontier to quest for new sources of technology enabling such a drastic increase of crop productivity. In this review, attempts to genetically engineer plant photosynthetic carbon reduction cycle and metabolic pathways to increase starch production are introduced.

• The Plant Pathology Journal
• /
• v.26 no.4
• /
• pp.417-420
• /
• 2010

The expression of HR-like lesion inducing gene of Oryza sativa (OsHRL) was slightly increased by Xanthomonas oryzae pv. oryzae (Xoo) infection. Transgenic rice plants over-expressing OsHRL gene were challenged with Xoo and the development of disease symptoms were examined to investigate the effect of OsHRL gene expression on plant defense responses. The over-expression of OsHRL increased disease resistance against Xoo compared with wild type plants.

• Korean Journal of Organic Agriculture
• /
• v.19 no.spc
• /
• pp.283-286
• /
• 2011

Powdery mildew and leaf mold were major diseases in organic cultured tomatoes. $NaHCO_3$ and $KH_2PO_4$ were selected as control agents for controlling tomato powdery mildew. Control effect of the selected control agents was increased when they were treated with oil-egg yolk mixtures (OEYO). Also four organic materials used commercially including copper hydroxide and sulfur, showed high control effect more than 90% in green house. Also two organic matters, copper hydroxide and sulfur showed high control effect in farmer's field. When tomatoes were cultivated in plastic house installed with circulation fan, incidence of powdery mildew and leaf mold was reduced by 56% and 60%, respectively.

• Korean Journal of Organic Agriculture
• /
• v.19 no.spc
• /
• pp.139-140
• /
• 2011

In organic farming agriculture, integration of cover crop into cropping system is recommended to improve the soil quality, prevent soil erosion, and control weeds. The aim of this study was to control weeds in soybean fields by integration of cover crops such as hairy vetch and rye. Due to cover crop mulching, weeds occurrence and growth were radically decreased. One month later after transplanting, weed growth inhibition rate of hairy vetch and rye treatment were 98% and 89% respectively, while crimson clover treatment were 50%. These effects last long over two month. The soybean yield of hairy vetch treatment was best. Therefore using hairy vetch as cover crop was highly recommended in organic soybean field.

• Korean Journal of Organic Agriculture
• /
• v.19 no.spc
• /
• pp.127-128
• /
• 2011

Vinegar has been considered as a potential organic herbicide, but more knowledge is needed about acetic acid concentration, application volume and use of adjutants on weed control. In this study, we determined optimum acetic acid concentration and spraying time on several weed species. Vinegar is more effective in broadleaf weeds than grasses. Vinegar is also effective in controlling younger weeds such as $3^{rd}$ to $4^{th}$ weeks after emergency. For example, $3^{rd}$ weeks after emergency weeds were easily controlled at 2-3% of vinegar solution. But $4^{th}$ weeks after emergency weeds were controlled at 4-5% of vinegar. Therefore vinegar concentration was recommended about 5%, and application time was when the weeds were young-within 3 leaf stage.