• Mycobiology
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• v.35 no.3
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• pp.129-134
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• 2007

Systemic effect of two plant growth-promoting rhizobacterial (PGPR) strains, viz., Pseudomonas fluorescens (Pf4) and P. aeruginosa (Pag), was evaluated on pea (Pisum sativum) against the powdery mildew pathogen Erysiphe pisi. Foliar spray of the two PGPR strains was done on specific nodal leaves of pea and conidial germination of E. pisi was observed on other nodal leaves, distal to the treated ones. Conidial germination was reduced on distant leaves and at the same time, specific as well as total phenolic compounds increased in the leaves distal to those applied with PGPR strains, thereby indicating a positive correlation. The strains induced accumulation of phenolic compounds in pea leaves and the amount increased when such leaves were get inoculated with E. pisi conidia. Between the two strains, Pag was found to be more effective than Pf4 as its effect was more persistent in pea leaves. Foliar application of PGPR strains for the control of powdery mildew of pea is demonstrated in vitro while correlating it with the increased accumulation of plant phenolics.

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

• KSBB Journal
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• v.10 no.1
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• pp.15-22
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• 1995

The embryos(6-8mm) isolated from seeds of Diospyros kaki were cultured on Murashlge-Skoog(MS), Woody Plant Medium(WPM), Campbell Durzen(CD), Lictvay's Medium(LM), Kao-Michaluk(KM), Nitsch, White, Heller, Wolter-Skoog(WS) media. The results showed that MS and WPM media were most suitable to the development of embryos into plantlets with length of $5.4{\pm}1.2 cm$ and 5-6 leaves. However, when LM and KM media were used, the addition of 1 to $2{\mu} moles/\ell GA_3$ was required for the germination of the embryos. Superoxide dismutase (SOD) activities, one of the changing factors in leaves according to physiological status displayed to be exceptionally significant in the leaves of plantlets germinated from seeds in potting sand soil contrary to those of cultured embryos specially around germination period.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1103-1108
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• 2016

Yam anthracnose caused by Colletotrichum gloeosporioides (C.g) is the most devastating disease of yam (Dioscorea sp.). In the present study, we evaluated the culture filtrate extract (CFE) of azalomycin-producing Streptomyces malaysiensis strain MJM1968 for the control of yam anthracnose. MJM1968 showed strong antagonistic activity against C.g in vitro. Furthermore, the MJM1968 CFE was tested for inhibition of spore germination in C.g, where it completely inhibited spore germination at a concentration of 50 μg/ml. To assess the in planta efficacy of the CFE and spores of MJM1968 against C.g, a detached leaf bioassay was conducted, which showed both the treatments suppressed anthracnose development on detached yam leaves. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM1968 as a fungicide for the control of yam anthracnose. The CFE non-treated plants showed a disease severity of >92% after 90 days of artificial inoculation with C.g, whereas the disease severity of CFE-treated and benomyl-treated yam plants was reduced to 26% and 15%, respectively, after 90 days. Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose. This study demonstrated the utility of the CFE from S. malaysiensis strain MJM1968 as a biofungicide for the control of yam anthracnose.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.168-174
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• 2014

It was conducted to evaluate the control efficacy of Bordeaux mixture on pepper anthracnose in vitro and in vivo. The suppressive efficacy of Bordeaux mixture on mycelial growth and spore germination of Colletotrichum acutatum was investigated on PDA, cellophane membranes and pepper fruits, respectively. Furthermore, its control value was evaluated on detached pepper fruits inoculated with C. acutatum by wound and non-wound inoculation method, and in fields. The mycelial growth of C. acutatum JC24 was inhibited by 90.0% on PDA amended with $937{\mu}g\;mL^{-1}$ of Bordeaux mixture. While the spore germination of C. acutatum JC24 was inhibited perfectly on cellophane membranes treated at $187{\mu}g\;mL^{-1}$ of Bordeaux mixture, that on fruits inoculated with the pathogen by wound inoculation and non-wound inoculation method was inhibited by 88.1% and 91.3%, respectively. Although the control value on fruits treated with $937{\mu}g\;mL^{-1}$ of Bordeaux mixture was 17.6% in wound inoculation method, it was 58.8% in non-wound inoculation method. In fields, when Bordeaux mixture was sprayed five times at 14 day-intervals, it showed 55.7% and 61.7% of control value in 2012 and 2013, respectively. We think Bordeaux mixture was able to use as an eco-friendly organic farming material to control pepper anthracnose based on the above-mentioned results.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.81-93
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• 2016

Rehmannia glutinosa(Gaertn.) DC. is a herbaceous perennial plant and belonging to the Scrophulariaceae and used as roots for medicinal part and purpose. R. glutinosa is and usually used for fresh rehmannia root or prepared rehmannia root. However, it is very difficult to propagate using the seeds because of lack germination so it is propagated using the vegetative method as the rootstock. Currently, propagation and harvesting using the rootstock of R. glutinosa has difficulties about production of the high quality and quantity in R. glutinosa because of root rot disease. To optimize in vitro cultures and to improve the rootstock and seedling of R. glutinosa after morphological and genetical determination, 5 plant culture media (MS, DJ, LS, QL, and WPM) were used in this study then WPM was selected for better growth, for multiplication condition(WPM + IAA 1.0 mg/L + IBA 0.5 mg/L), and for root enlargement condition(WPM + NAA 0.1 mg/L) of R. glutinosa. Based on these results, in vitro seedlings of R. glutinosa were transferred to soil for acclimation with environment adaptation and shown the positive effects about root enlargement and root formation. Therefore, it can be used for high quality of R. glutinosa production and production of the rootstock based on propagation using in vitro seedlings of R. glutinosa.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.834-840
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• 2008

In order to improve the use of pumpkin seed, the present study was performed to isolate compositions of the bitter components which were not seen in pumpkin seed itself but newly biosynthesized during germination of the seed. The compositions isolated were then further purified by TLC and preparative HPLC in which a fraction with Rf 0.73 and RT 10.3 was obtained. Cucurbitacin E with molecular weight of 557 from the fraction was finally identified by subsequent structural analysis of LC-MS/MS. The production of cucurbitacin E peaked with 224.7 mg/kg at 4 days of germination at $20^{\circ}C$ with the water supply at ntervals of 48 hrs in the darkness, while that of cucurbitacin E reached 146.7 mg/kg in the brightness. In vitro-cell based assays demonstrated that the isolated and purified cucurbitacin E inhibited proliferation of A549 lung cancer cells and suppressed expression of the IL-$1{\beta}$- or PMA-induced cyclooxygenase-2, an inflammatory protein in A549 cells, suggesting its anti-proliferative and anti-inflammatory activities.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.131-141
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• 2017

This study was conducted to investigate in vitro mass propagation methods suitable for each growth stage of A. aristata (G. Forst.) Tindale, from spore germination to sporophyte formation. Among spores germinated in $1/8-1{\times}MS$ medium and Knop medium, Knop medium yielded the highest germination percentage (87.1%). We cultured prothalli obtained from germinating spores for 8 weeks on media with different concentrations of sucrose and active carbon, as well as different concentrations and ratios of nitrogen, to select a suitable growth medium. A. aristata (G. Forst.) Tindale prothalli grew most actively in MS medium with 3% sucrose and 20 : 40 mM of $NH_4Cl$ and $KNO_3$ (total concentration of 60 mM). We investigated sporophyte formation according to soil type, finding that bedding soil mixed with perlite at a 2 : 1(v / v) ratio yielded the highest number of sporophytes per pot ($73.8/7.5{\times}7.5cm\;pot$). By contrast, when peat moss was used alone or mixed with other substrates, prothallus development and sporophyte formation were suppressed. Therefore, the most effective propagation method for A. aristata (G. Forst.) Tindale is to grow prothalli in MS medium and to induce sporophyte formation in a mixture of bedding soil and perlite (v / v = 2 : 1).

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.211-217
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• 2008

To build up data for mutation breeding of lily, sensitivity to irradiation of bulb, seed and pollen was investigated. The bulbs of seven cultivars including 'New Wave' were very sensitive to gamma rays. Non-irradiated bulbs produced plants with bloom as normal. However, irradiated bulbs showed retarded growth and did not flower. Bulbs of 'New Wave' and 'Tiny Dino' irradiated with 125Gy gamma rays survived, but their growth rate dropped considerably. Part or whole leaves of the other cultivars except 'New Wave' and 'Tiny Dino' withered. Moisture content of individual scale was 72~78% depending on cultivar. Bulblet formation from untreated scales was 100%. Among all irradiated scales only 'Siberia' scales showed 8.5% bulblet formation when irradiated with 50Gy gamma rays. Pollen germination as affected by gamma ray irradiation had no consistent tendency. When dosage of $F_1$ 'Augusta' seeds reached 300Gy, their survival ratio was drastically decreased. Bulblet formation in vitro was observed only in non-irradiated seeds. Lethal dose ($LD_{50}$) of seed was less than 100Gy. Height and width of $F_1$ 'Augusta' bulblets in vitro irradiated with gamma rays decreased as dosage increased regardless of the culture method. The percentage shoot formation was 100% in non-irradiated bulblets and 15~60% in irradiated ones.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.115-121
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• 2014

This study was performed to investigate the effect of conidial density, wetness period and temperature on conidial germination, appressoria formation and disease incidence. While there was not significantly correlated between conidial density and temperature, and conidial germination and appressoria formation, there was a significant correlation between those factors and disease incidence. The longer wetness period was, the higher the ratio of conidial germination, appressoria formation and the disease incidence was. The optimum conidial density, temperature and wetness period was $1{\times}10^6$ conidia $mL^{-1}$, $30^{\circ}C$ and 5 days, respectively. In case the wetness period was more than 5 days, the typical symptom was not found on pepper fruits because of the overgrowth of mycelia. Using this fruit assay method, which the pepper anthracnose pathogens were inoculated by spraying spore suspension on non-wounded or wounded pepper fruits, control effect of three fungicides were evaluated against pepper anthracnose by the protective and/or the curative application. Propineb showed high protective control activity, while it showed curative control activity on unwounded fruits, but did not showed curative control activity on wounded fruits. Tebuconazole, one of curative fungicide, showed higher control activity in non-wound inoculation than wound inoculation. Trifloxystrobin, one of strobilurin group, showed high both protective and control activity against anthracnose. In conclusion, we supposed that the newly developed in vitro pepper fruit assay can be used to evaluate antifungal activity of control agents against pepper anthracnose.