• Korean Journal of Organic Agriculture
• /
• v.23 no.3
• /
• pp.567-582
• /
• 2015

Botrytis cinerea infects stems, leaves and fruits of greenhouse tomato and can cause serious economic losses. This study was conducted to develop organic farming control method against tomato gray mold. Twenty two organic farming materials including mineral and plant extracts were screened for the suppressive activity against Botrytis cinerea, in vitro and in vivo. Among the organic farming materials, sulfur, copper, Chinese twinleaf extract and rhubarb extract decreased by 51.7-90% of the spore germination of Botrytis cinerea. Also, gray mold incidence was reduced more than 90% on tomato stems by treating sulfur, seaweed extracts, rhubarb root extracts and Chinese twinleaf extract. After the selected four organic farming materials were applied on tomato cultivated in greenhouse, their control effects against the tomato gray mold were tested. When the water soluble sulfur was foliar-sprayed on the tomato leaves infected by artificial inoculation with spore suspension of Botrytis cinerea, it showed 87.9% of control value. Also, control activity of the water soluble sulfur was paralleled with chemical fungicide, diethofencarb+carbendazim. The above mentioned results indicate the sulfur formulation can be used as chemical fungicide alternatives for controlling tomato gray mold in the greenhouse.

• Korean Journal of Environmental Agriculture
• /
• v.31 no.1
• /
• pp.60-67
• /
• 2012

BACKGROUND: Anthracnose disease caused by Collectotrichum spp. is one of the most important worldwide devastating diseases in red pepper plants. Fungicides using plant extracts have several advantages, compared to synthetic chemical fungicides, because they are naturally occurring compounds, are usually safe for agricultural environment and are used for producing highly valuable agricultural products. Efforts for seeking an anti-fungal activities using naturally occurring compounds were mostly conducted from medicinal plant extracts. Sap of Rhus verniciflus was known to have healing effects on several human diseases. Recently, the extracts of Rhus verniciflus were actively tested for anti-cancer, anti-oxidative, and anti-fungal effects. In this study, the extract of Rhus verniciflus was tested for anti-fungal activity against Colletotrichum spp., which cause anthracnose in red-pepper. METHODS AND RESULTS: After neutralizing extracts of Rhus verniciflus (urushiol contents 70%) with autoclave, the crude extracts were used to investigate inhibitory effects for mycelial growth and spore germination of Colletotrichum spp. on PDA media. The mycelial growth and spore germination of Colletotrichum spp. were inhibited 18-39% and over 50% in response to crude extract of R. verniciflus (1.0 mg/mL). After spraying the extracts at the same concentrations above and then artificially inoculating Colletotrichum spp. on blue and red-pepper fruits, in vitro inhibition effects were examined. At 1.0 mg/mL, the crude extract of R. verniciflus showed inhibition activity in anthracnose incidence on blue- and red-pepper as 68.1-75.0%, through a artificial inoculation of Colletotrichum spp. in a laboratory. For in vivo inhibitory effects, the extracts (1.0, 0.1, and 0.01 mg/mL) were treated on red-pepper plants grown in green house 3 times at the interval of 1 week. Then inhibitory effects were determined by counting diseased fruits at 1 week after final treatment. The incidence of anthracnose was inhibited over 60% in the greenhouse by treatment of crude extract of R. verniciflus (1.0 mg/mL). CONCLUSION(s): Extracts of Rhus verniciflus were shown to have inhibitory effects on mycelial growth, spore germination of Colletotrichum spp. in vitro and on occurrence of anthracnose on pepper fruit in green house.

• Microbiology and Biotechnology Letters
• /
• v.26 no.5
• /
• pp.379-386
• /
• 1998

Deterioration of food is in general caused by the presence of microorganisms and chemical compounds of food itself. There exists antimicrobial compound in the food, however, addition of food antiseptics, additives, or physico-chemical processing is a common practice. The safety of artificial chemical antiseptics became a serious public concern, therefore, new natural antiseptic compounds are in need to be developed. We have isolated a new natural antifungal protein (KBS-B2) from Astragal seed through ammonium sulfate precipitation and column chromatography using FPLC Mono-S and Superose 12HR. The purified protein inhibited growth of Candida albicans, and spore germination of food spoiling fungi such as Aspergillus ochraceus, Penicillium expensum, P. digitatum and Botrytis cineria. Antifungal effect of the KBS-B2 protein could be directly assayed by bioautography overlaying the fungal spores on the electrophoresed acrylamide gel. The comparison of N-terminal amino acid sequences of the KBS-B2 with known antifungal protein revealed that had 50% homology to thaumatin and zeamatin like proteins.

• Research in Plant Disease
• /
• v.17 no.1
• /
• pp.82-85
• /
• 2011

Bakanae disease symptom were observed in barnyard grass in paddy field in Heanam, Jeonnam. The infected plants were blighted and white mass of spore were formed on the stem. Fusarium species were isolated from infected stem and the isolates were identified as Fusarium fujikuroi based on their morphological and molecular characteristics. The isolates of F. fujikuroi were assigned to reference of F. fujikuroi among related Fusarium species based on the translation elongation factor 1-alpha gene sequence. Pathogenicity of the fungal isolates was confirmed on seedlings of rice and barnyard grass by artificial inoculation. The results indicated that barnyard grass can be inoculum source of Bakanae disease on rice. Thus, effective weed management is necessary to Bakanae disease control and healthy seed production.

• Korean Journal of Veterinary Research
• /
• v.16 no.2
• /
• pp.165-171
• /
• 1976

Experimental approaches on the effectiveness of thimerosal to control growth of Nosema apis (Zander, 1909) were carried out in the rearing honey bees. The rearing honey bees were artificially infected with various levels of spore isolated from local honey bees. The results obtained were summarized as follows: 1. In the experiments of therapeutic chemicals for Nosema disease, 0.01% and 0.02% thimerosal of sucrose-honey mixture was the most effective agent but the each concentration of amprolium, furazolidone, hygiene, sulfadimethoxine and terramycin did not show the any effects 2. It showed very high therapeutic effectiveness (over than 90%) that the treatment of three times every other day after the treatment of three times consecutive every day with 0.01% thimerosal, or the treatment of three times consecutive every day with 0.02% thimerosal. 3. When 0.02% thimerosal was administered three times consecutive every day to honey bees at the 4th day before artificial inoculation of N. apis, it showed very high degree (100%) of prevalence control effectiveness, and it also showed high degree (over than 90%) in administration at the 7th day before, and over than 80% at the 10th day before. Then authors found that thimerosal has the prevalence control effectiveness as well as the treatment effectiveness. 4. In the rearing honey bee colony, 0.02% thimerosal showed the high degree (over than 80%) of therapeutic effectiveness with the various levels which contained from the light decree of infection to the severe degree of it.

• The Korean Journal of Mycology
• /
• v.39 no.3
• /
• pp.213-216
• /
• 2011

Gray mold symptoms were frequently observed on green twigs, blossoms, leaves, and fruits of blueberry trees grown in greenhouses in Cheongyang, Dangjin, Daejeon, and Jeju during disease survey in eight locations of Korea from 2007 to 2010. The disease symptoms were not observed in the fields of the other locations investigated. The disease incidence ranged 1~30% in the greenhouses investigated. A total of 27 single spore isolates of Botrytis species were obtained from the gray mold symptoms, and all the isolates were identified as Botrytis cinerea based on their morphological and cultural characteristics. Four isolates of the fungus were tested for pathogenicity to leaves of four varieties of blueberry trees by artificial inoculation with conidial suspensions. All the tested isolates caused gray mold symptoms on the leaves, which were similar to those observed in the greenhouses. This is the first report that B. cinerea causes gray mold of blueberry trees grown in greenhouses in Korea.

• The Korean Journal of Mycology
• /
• v.48 no.4
• /
• pp.369-379
• /
• 2020

Black mold was frequently observed on tomatoes grown in a greenhouse in Suwon, Korea in July 2018. The incidence of the disease was 5.0-25.0% (average 12.3%) and 2.0-7.0% (average 3.7%) in the context of tomato and cherry tomato fruits, respectively. Sixteen single-spore isolates of Alternaria sp. were obtained from the diseased fruits and investigated for their morphological characteristics. Among the isolates, eight were used for sequencing analysis. All of the isolates were identified as Alternaria alternata based on their morphological and molecular characteristics. The pathogenicity of four isolates of A. alternata was investigated using three varieties each of tomato and cherry tomato via artificial inoculation. All of the isolates induced black mold symptoms on the inoculated tomato fruits. Notably, the symptoms were similar to those observed in the greenhouse. However, the pathogenicity tests revealed that different tomato varieties presented distinct patterns of susceptibility to the isolates. This is the first report of A. alternata causing black mold on tomato fruits in Korea.

• The Korean Journal of Mycology
• /
• v.25 no.4 s.83
• /
• pp.311-319
• /
• 1997

These studies were carried out to develop an artificial cultivation method. The diameter and thickness of pileus ranged $1.5{\sim}7.0\;cm$ and $0.8{\sim}3.0\;cm$, respectively. The diameters of stipe were $1.2{\sim}2.5\;cm$ and the lengthes were $4.5{\sim}9.0\;cm$. The spore fingerprint was white. The sizes were spore $10.8{\sim}12.2{\times}4.35{\sim}5.65\;{\mu}m$, basidia $50.0{\sim}59.2{\times}7.4{\sim}7.8\;{\mu}m$, nalsistidia $21.75{\sim}28.7{\times}4.8{\sim}6.1\;{\mu}m$, pileus hymenium cell $50.6{\sim}66.0{\times}4.4{\sim}6.7\;{\mu}m$, and stipe hymenium cell $28.6{\sim}33.0{\times}5.5{\sim}6.6\;{\mu}m$. The thirty percent mixture of rice and wheat bran into sawdust gives the high density of mycelia and the good development of fruiting structure. The optimum water contents of sawdust substrates were $60{\sim}65%$ in which condition the mycelium grows well and gives high density. In PP bottle cultivation, the first fruiting period was $6{\sim}8$ days earlier in nonscratching samples than scratching ones, but the quantity of fruiting body was higher in scratching samples than nonscratching ones. In the case of PP bag cultivation, the first fruiting was 10 days faster, and the quantity of fruiting bodies was 30% higher in samples with 30% wheat bran than those with rice bran. The fleshiness of stipe was $2{\sim}3$ times harder than that of pileus.

• Korean Journal of Food Science and Technology
• /
• v.40 no.5
• /
• pp.562-567
• /
• 2008

The primary objective of this study was to select a probiotic starter for cheonggukjang using 60 strains isolated from rice straw. Among isolated strains, only 8 strains including strain B-59 evidenced proteolytic, amylolytic and soybean activity. These 8 strains were all gram-positive, spore-forming rods. The B-59 strain evidenced antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Pseudomonas fluorescens, and Vibrio parahaemolyticus. The antimicrobial activity of isolated B-59 was verified by its ability to inhibit the growth of S. aureus, L. monocytogenes, P. fluorescens, and V. parahaemolyticus. The selected B-59 strain was indentified as Bacillus licheniformis, as shown by a result of 99.0% homology upon API kit analysis. The selected B-59 strain also displayed viability in pH 2.5 artificial gastric juice, artificial bile acid, NaCl (2, 4, 8, 16, 32%), and ethanol (4, 8, 16, 32%). The antioxidative activity of the strain B-59 culture was assessed via a DPPH free radical scavenging activity assay. The activity increased with an increasing in the fermentation time of strain B-59 for 20 hours.

• The Korean Journal of Mycology
• /
• v.26 no.2 s.85
• /
• pp.182-186
• /
• 1998

The result of study on the morphological feature of fruitbody, soil characteristics and enviromental condition of habitat of Tricholoma giganteum in Korea was as follows: The Pileus was $5.5{\sim}28.0\;cm$ in diameter and $1.5{\sim}3.7\;cm$ in thickness, indicating of yellowish white, beige, or ivory color. The lamellae were $18{\sim}20\;mm$ in diameter; the stipe was $9.0{\sim}35.7\;cm$ long and $1.0{\sim}3.0\;cm$ wide. The spores were $3.5{\sim}4.8{\times}5.7{\sim}7.4\;{\mu}m$ in size, ellipsoid, hyaline and the spore deposit white. The basidia were $6.1{\sim}7.0{\times}32.2{\sim}39.2\;{\mu}m$ in size. Cheiloystidia were $3.5{\sim}4.4{\times}30.5{\sim}33.1\;{\mu}m$ in size. Pileipellis were $3.3{\sim}4.4{\times}33.0{\sim}55.0\;{\mu}m$ wide and had clamp connection. Stipitipellis were $2.2{\sim}3.3{\times}88.0{\sim}93.1\;{\mu}m$ in size. Texture of soil in habitate of T. giganteum was silty loam, and organic materials content and available phosphate content in this soil were high as comparision to general soil in Korea. In the time of the mushrooms sprout, the room temperature indicated $25{\sim}27^{\circ}C$, their humidity showed $80{\sim}83%$, and the brightnesses were 328 Lux.