• Research in Plant Disease
• /
• v.7 no.1
• /
• pp.25-30
• /
• 2001

Influence of soil flooding with organic matters amendment at various temperatures on population changes of fungi, including Fusarium, and bacteria in ginseng-replanting field soils was examined to evaluate the effective flooding conditions for reducing the progress of ginseng root rot. Populations of Fusarium spp. and total fungi in flooded soils declined with days after flooding. The higher was the temperature in range of 20$\^{C}$ to 35$\^{C}$, the greater was the effect of flooding on the decrease of the fungal population. Flooding of soils with organic matters amendment had synergistic effect on the decrease of the fungal population at the same temperature; Fungal populations in flooded soils with and without organic matters amendment were reduced to 1/100 and 1/10, respectively, relative to those in non-flooded soils after 60 days of treatment at 30$\^{C}$. rice straw seemed to be more effective than greens. Population changes of total bacteria in flooded soils were similar to the trend of total fungi. However, the flooding seemed to influence less effect on the bacterial population than on the fungal population. Based on these experiments, we suggest than the progress of ginseng root rot in ginseng-replanting field soils may be significantly reduced by flooding them for longer than 3 months near at 30$\^{C}$ after amendment of organic matters.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.4
• /
• pp.266-287
• /
• 2004

The non infecting, plant associated bacteria have attracted increased attention for stimulating plant growth and as environmental friendly plant protecting agents. Pink-pigmented facultatively methylotrophic bacteria (PPFMs), classified as Methylobacterium spp., are persistent colonizers of plant leaf surfaces. As the leaves of most or all plants harbor PPFMs that utilize leaf methanol as their sole source of carbon and energy, which is a specific attribute of the genus Methylobacterium. Although they are not well known, these bacteria are co-evolved, interacting partners in plant metabolism. This claim is supported, for example, by the following observations: (1) PPFMs are seed-transmitted, (2) PPFMs are frequently found in putatively axenic cell cultures, (3) Low numbers of seed-borne PPFMs correlate with low germinability, (4) Plants with reduced numbers of PPFM show elevated shoot/root ratios, (5) Foliar application of PPFMs to soybean during pod fill enhances seed set and yield, (6) Liverwort tissue in culture requires PPFM-produced vitamin B12 for growth, (7) treated plants to suppress or decrease disease incidence of sheath blight caused by Rhizoctonia solani in rice, and (8) the PPFM inoculation induced number of stomata, chlorophyll concentration and malic acid content, they led to increased photosynthetic activity. Methylobacterium spp. are bacterial symbionts of plants, shown previously to participate in plant metabolism by consuming plant waste products and producing metabolites useful to the plant. There are reports that inform about the beneficial interactions between this group of bacteria and plants. Screening of such kind of bacteria having immense plant growth promoting activities like nitrogen fixation, phytohormone production, alleviating water stress to the plants can be successfully isolated and characterized and integration of such kind of organism in crop production will lead to increased productivity.

• Research in Plant Disease
• /
• v.15 no.3
• /
• pp.222-229
• /
• 2009

A Pseudomonas strain SG3 producing biosurfactant and showing antifungal and insecticidal activities was isolated from agricultural soil severely contaminated with machine oils. The antagonistic bacterium inhibited mycelial growth of all of the tested fungal pathogens. The fermentation broth of SG3 also effectively suppressed the development of various plant diseases including rice blast, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose. An antifungal substance was isolated from the fermentation broth of SG3 by ethyl acetate partitioning, silica gel column chromatography and preparative HPLC under the guide of bioassay. The chemical structure of the antifungal substance was determined to be rhamnolipid B by mass and NMR spectral analyses. The antifungal biosurfactant showed a potent in vivo antifungal activity against gray mold and late blight on tomato plants. In addition, rhamnolipid B inhibited mycelial growth of B. cinerea causing tomato gray mold and zoospore germination and mycelial growth of P. infestans causing tomato late blight. Pseudomonas sp. SG3 producing rhamnolipid B could be used as a new biocontrol agent for the control of plant diseases occurring on tomato plants.

• Research in Plant Disease
• /
• v.19 no.3
• /
• pp.183-187
• /
• 2013

Barley kernel discoloration (KD) leads to substantial loss in value through downgrading and discounting of malting barley. The objective of this research is to investigate fungal distribution and varieties resistance to KD in Korean two-rowed barley. Several fungal organisms including Alternaria spp., Fusarium spp., Aspergillus spp., Epicoccum spp. and Rhizopus spp. were isolated from Korean two-rowed barley representing KD. The symptoms of KD were brown and black discolorations of the lemma and palea. The most frequently detected fungal species was Alternaria spp. which exhibited 69.1% and 72.2% in 2011 and 2012, respectively. Epicoccum spp., Fusarium spp., and Aspergillus spp. were also detected. Fusarium spp., primary pathogen of barley head blight, were rarely occurred in the 2011 and their occurrence increased to 4.7% in 2012. Twenty cultivars of Korean two-rowed barely were evaluated to KD. The average percentage of KD was 8.0-36.0% in 2011 and 5.2-36.6% in 2012. Two cultivars ('Sacheon 6' and 'Dajinbori') showed KD of 6.2% to 8.8% and determined resistant, however 'Samdobori' and 'Daeyeongbori' demonstrating KD of 22.2-36.6% were highly susceptible. 'Jinyangbori', 'Danwonbori', 'Sinhobori' and 'Kwangmaegbori' showing KD of less than 15% were moderately resistant cultivar.

• Research in Plant Disease
• /
• v.11 no.2
• /
• pp.158-161
• /
• 2005

Stenotrophomonas maltophilia BW-13 is a potent biocontrol agent to control crisphead lettuce bottom rot caused by Rhizoctonia solani. To define the optimum conditions for the mass production of the S. maltophilia BW-13, we have investigated optimum culture conditions and effects of various carbon sources on the bacterial growth. The optimum initial pH and temperature were determined as pH $6.0\~7.0 and $35^{\circ}C$, respectively. For the selection of effective carbon source for the mass production, we tested the low molecular carbon sources such as sucrose, glucose, lactose, maltose, manose and the high molecular carbon source such as dough conditioner, rice bran, corn starch, sweet potato starch. As the results, the addition of dough conditioner in a basal medium ($1.25\%\;K_{2}HPO_4,\;0.38\%\;KH_{2}PO_4,\;0.01\%\;MgSO_4{\cdot}7H_{2}O,\;0.5\%\;Yeast extract$) was able to achieve higher cell density and the antifungal activity than others. Therefore, the basal medium containing $3\%$ dough conditioner (named as dough conditioner medium) was finally selected the optimized media for the mass production of BW-13 strain.

• Journal of the Korean Society of Food Culture
• /
• v.5 no.3
• /
• pp.331-347
• /
• 1990

This study was designed under the purpose to analyze the Korean Traditional Folk Remedies on food, to submit the basic statistical data, and to utilize them by examining how much they know about the Korean Traditional Folk Remedies and also by examining how frequently they used them. The sample was consisted of 312 housewives living in Daegu, Kyungsan city and Kyungsan-eup, the survey was made by use of questionaires from July 15 to August 1 1989. The results are as follows 1. Analysis of Folk Remedical Contents 1) The method of the Folk Remedies used in this area was mainly food, which can be easily found around their house and easy to use, it was possible to apply scientific principles in some cases. 2) The major popular method was shown to feed boiled barley or brown rice which are known as the Folk Remedy for Diabetes. 3) The ANOVA of variable shows the significant influence on each object which age, religion, the level of education, job, monthly income, and the area except family formation. 2. The Frequency of Folk Remedies and additional analysis 1) The most frequently used Folk Remedy was Arterio-sclerosis(1.44), which is followed by the loss of Eyesight(1.40), Hang over(1.28), Couth(1.27), Cold(1.26) etc. 2) In the analysis of Pearson Correlation between frequencies of Folk Remedies used, and demographic variables such as age(p<.05), the monthly income(p<.01), in that area, total number of response items showed a positive correlation. 3. The source to learn about Folk Remedy. 1) It is acknoledged that they are mostly instructed by their forefathers, friends, neighbors, professional textbooks, mass communications, herb doctors, other medical sources or education at school etc. 2) The ANOVA of Variables shows the big differences between each group by age. Based on the above findings, the following suggestions are made ; Most of Korean Traditional Folk Remedies are recognized scientific and reasonable which are based on the scientific research and herb medicine therefore it should be made good use of for our life in good health additionally. I hereby insist that the importance of our Folk Remedies should be reviewed and focused for maintenance our health.

• The Journal of Korean Medical History
• /
• v.19 no.1
• /
• pp.111-133
• /
• 2006

This study was examined to reveal the medical Science of Balhae which was not well displayed until now. For this, the category of the medical science of Balhae(渤海) was decided in diachronic and synchronic perspective and the concrete contents of the medical science of Balhae(渤海) was presumed. Balhae(渤海) succeeded to the medical science of Koguryo(高句麗) and its orthodoxy. Through the interchange between Balhae(渤海) and the country as Dang(唐) and Shilla(新羅), Balhae(渤海) accepted new medical knowledge. Balhae(渤海) had a customs to eat a cake made of rice flour and artemisia paste on the Tano Festival(端午) to overcome its constitutional character. And medicines as Gon-po(昆布), Doo-shi were treated valuable. and they used Ondol(溫突). Balhae(渤海) advanced suigeneris abscess medicine(治腫醫學), and they valued much of Hyangyak(鄕藥). And they took the serious view on the scripture in the education and on the simplic in the clinic. It shows Balhae(渤海) had the unique medical tradition of our nation. The medical institution and medical educational system of Balhae(渤海) was fundamental to that of Koguryo(高句麗), and it was established in the reference of the system of Dang(唐) and Shilla(新羅). It influenced the establishment of medical system and medical education of Corea(高麗) later on. And the medical doctor of the Balhae(渤海) who was dispatched to Japan imparted the advanced medicine of Balhae(渤海) and it was fundamental to the Japanese medical development. Balhae(渤海) produced superior acupuncture on the basis of superior materials which are represented as metalwork technology and Corea-copper(高麗銅) which are handed down from the Old-Chosun(古朝鮮) and Koguryo(高句麗). And we can suppose the level of Balhae(渤海) through the fact that the acupunctual technique of Koguryo(高句麗) was spread out to the nearby country. By the tradition of acupuncture and moxibustion, the theory of Bi-bo(裨補) that cure a disease on the theory of acupuncture and moxibustion appeared in the north and south branch period(南北國時代). And we can prusure the level of acupuncture of Balhae(渤海) through this fact. Balhae(渤海) educated herbal medicine with priority given to Shin-nong-bon-cho-kyong(神農本草經) stand on the serious view on the scripture. They produced a various herbs on the basis of broad territory and suigeneris herbal medicine. It is famous herb of Balhae(渤海), that To-sa-ja, Gon-po(昆布), Doo-shi, Ginseng(人蔘), Woo-hwang(牛黃), Song-ja(松子), Hwang-myung-kyo (黃明膠), Baek-bu-ja(白附子), Sa-hyang(麝香), Honey(蜜).

• Research in Plant Disease
• /
• v.11 no.1
• /
• pp.66-71
• /
• 2005

The effect of medium components such as wheat bran, rice bran, oat meal, and soybean meal as basic ingredients and KH2PO4, glucose, and molasses as additives on mass production and anti-potato common scab activ ity of a streptomycete A020645 strain as a biocontrol agent (BCA) candidate was investigated. Of basicingredients, oat meal was the best one for mass poduction and enhancement of anti-potato common scabactivity. The biomass production of the active strain was more enhanced when 0.1-0.01.% glucose or molassesas additive were added into the basic medium. These information may have important implications in applying for effective formulation of BCA.

• Research in Plant Disease
• /
• v.18 no.2
• /
• pp.109-116
• /
• 2012

A bacterial strain antagonistic to some fungal phytopathogens was isolated from the stem of a Persimmon tree in Yeongam, Korea. This bacterium was identified as Bacillus subtilis by 16S rRNA gene sequencing and designated as B. subtilis GDYA-1. In in vivo experiment, the fermentation broth exhibited antifungal activities against Magnaporthe oryzae on rice plants, Phytophthora infestans on tomato plants, and Puccinia recondita on wheat plants. We isolated one antifungal compound and its chemical structure was determined by mass and $^1H$-NMR spectral data. The antifungal substance was identified as benzoic acid. It inhibited mycelial growth of M. oryzae, Rhizoctonia solani, Sclerotinia sclerotiorum, and P. capsici with minimum inhibition concentration (MIC) values, ranging from 62.5 to 125 ${\mu}g/ml$. Moreover, the substance effectively suppressed Phytophthora blight of red pepper caused by P. capsici in a pot experiment. To the author's knowledge, this is the first report on the antifungal activity of benzoic acid against phytopathogenic fungi. Benzoic acid and B. subtilis GDYA-1 may contribute to environmental-friendly protect crops from phytopathogenic fungi.

• The Plant Pathology Journal
• /
• v.39 no.4
• /
• pp.361-373
• /
• 2023

In plant-pathogen interactions, Magnaporthe oryzae causes blast disease on more than 50 species of 14 monocot plants, including important crops such as rice, millet, and most 15 recently wheat. M. oryzae is a model fungus for studying plant-microbe interaction, and the main source for fungal pathogenesis in the field. Here we report that MoJMJD6 is required for conidium germination and appressorium formation in M. oryzae. We obtained MoJMJD6 mutants (ΔMojmjd6) using a target gene replacement strategy. The MoJMD6 deletion mutants were delayed for conidium germination, glycogen, and lipid droplets utilization and consequently had decreased virulence. In the ΔMojmjd6 null mutants, global histone methyltransferase modifications (H3K4me3, H3K9me3, H3K27me3, and H3K36me2/3) of the genome were unaffected. Taken together, our results indicated that MoJMJD6 function as a nuclear protein which plays an important role in conidium germination and appressorium formation in the M. oryzae. Our work provides insights into MoJMJD6-mediated regulation in the early stage of pathogenesis in plant fungi.