• Mycobiology
• /
• v.29 no.2
• /
• pp.96-99
• /
• 2001

Withametelin, a steroidal compound isolated from leaves of Datura metel L.(Solanaceae), showed antifungal activity against some plant pathogenic as well as saprophytic fungi tested in vitro. Except Curvularia maculans and Colletotrichum sp., spore germination of all the other 23 fungi was inhibited significantly at 125 to 1000 ppm. Out of the 25 fungi tested, Curvularia sp., Cercospora abelmoschi, Heterosporium sp., Erysiphe cichoracearum and Ustilago cynodontis were most sensitive as there was complete inhibition of germination at 1000 ppm. Similarly, spores of Alternaria brassicae, Curvularia lunata and Helminthosporium pennisetti showed less than 3% germination at the same concentration. Rest of the fungi showed more than 15% spore germination at the same concentration.

• Archives of Pharmacal Research
• /
• v.16 no.1
• /
• pp.62-67
• /
• 1993

A series of 12 pyrimidine derivatives were prepared and tested in vitro against growth, sporulation and nucleic acids of Fusarium oxysporum f. sp. lycopersici and Helminthosporium oryzae. Intorduction of thiazole ring together with two aryl groups to 2-aminopyrimidine induced drastic toxicity for both fungi. Pyrimidine derivatives with aryl groups were less toxic. Nitro groups were found to enhance the toxicity of the pyrimidine derivatives especially when substituted in ortho-position of the aryl groups. Inhibition of nudeic acids synthesis of both fungi was attributed mainly to the presence of thiazole ring.

• The Korean Journal of Mycology
• /
• v.10 no.3
• /
• pp.119-124
• /
• 1982

The characteristics of the six different agricultural soil from Michigan were as follows. Colwood and Capac soil were loam, Gilford and Ceresco were sandy clay loam, Sission was clay loam, and Spinks was sandy loam. pH of Gilford sandy clay loam was 6.6 whereas that of the soil ranged $5.4{\sim}5.9$. Gilford sandy loam found to contain a relatively higher amount of organic matters as compared to other soils. Furthermore, the numbers of bacteria in Gilford sandy clay loam were significantly higher than those in other soils. The populations of fungi in Gilford sandy clay loam and Colwood loam soils were significantly greater than those in other soils. On the other hand, the densities of actinomycetes in Gilford sandy clay loam and Ceresco sandy clay loam soils were significantly different from those in other soils. The population of anaerobic bacteria varied depending on the soils; Ceresco sandy clay loam, Capac loam, Colwood loam soils have higher numbers of bacteria, whereas Gilford sandy clay loam was very lesser than the other soils. In the $^{14}C-glucose$ respiration by soil microorganisms after 10 hrs, the respiration rate was decreasing in the order of Ceresco sandy clay loam, Spinks sandy loam, Colwood loam, Sission clay loam, Capac loam and Gilford sandy clay loam. Germination of test propagules on natural soil soil was $0{\sim}5%$, and it was germinated $90{\sim}98%$ on autoclaved soil and PDA. The propagules differed in thier germination response to nutrients added to the soils. In general, more nutrients were required to promote germination on Capac loam and Gilford sandy loam soil than Spinks sandy loam soil. Especially Mortierella n. sp. required more nutrients for germination to obtain the same ratio as Helminthosporium victoriae.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 1994.06a
• /
• pp.50-61
• /
• 1994

Biological control of important fungal diseases such as Phytophthora blight of red pepper, gary mold rot of vegetables, and powdery mildew of many crops was attempted using an antagonistic bacterium, Bacillus sp. AC-1 in greenhouses and fields. The antagonistic bacterium isolated from the rhizosphere soils of healthy red pepper plant was very effective in the inhibition of mycelial growth of plant pathogenic fungi in vitro including Phytophthora capsici, Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Valsa mali, Fusarium oxysporum, Pythium ultimum, Alternari mali, Helminthosporium oryzae, and Colletotrichum gloeosporioides. Culture filtrate of antagonistic Bacillus sp. AC-1 applied to pot soils infested with Phytophthora capsici suppressed the disease occurrence better than metalaxyl application did until 37 days after treatment in greenhouse tests. Treatments of the bacterial suspension on red pepper plants also reduced the incidence of Phytophthora blight in greenhouse tests. In farmers' commercial production fields, however, the controlling efficacy of the antagonistic bacteria was variable depending on field locations. Gray mold rot of chinese chives and lettuce caused by Botrytis cinerea was also controlled effectively in field tests by the application of Bacillus sp. AC-1 with control values of 79.7% and 72.8%, respectively. Spraying of the bacterial suspension inhibited development of powdery mildew of many crops such as cucumber, tobacco, melon, and rose effectively in greenhouse and field tests. The control efficacy of the bacterial suspension was almost same as that of Fenarimol used as a chemical standard. Further experiments for developing a commercial product from the antagonistic bacteria and for elucidating antagonistic mechanism against plant pathogenic fungi are in progress.

• Mycobiology
• /
• v.34 no.3
• /
• pp.120-123
• /
• 2006

Phytoterpenoid isolated from Artabotrytis odoratissimus inhibited spore germination of some plant pathogenic as well as saprophytic fungi e.g. Alternaria alternata, A. solani, Cercospora sp., Curvularia maculans, C. pennisetti, Fusarium udum, Helminthosporium echinochlova, H. frumentacie, H. penniseti and Ustilago cynodontis. In Curvularia maculans and H. frumentacie, spore germination was completely inhibited at 2000 ppm. However, Curvularia maculans and C. pennisetti showed considerable sensitivity to this chemical even at 500 ppm.

• Mycobiology
• /
• v.35 no.2
• /
• pp.69-71
• /
• 2007

1-Corydalmine, an alkaloid isolated from roots of Corydalis ehaerophylla inhibited spore germination of some plant pathogenic as well as saprophytic fungi e.g. Alternaria brassicae, A. brassicieola, A. solani, Curvularia lunata, C. maculans, C. sp., C. pallseens, Erysiphe pisi, Fusarium udum, Helminthosporium species, H. penniseti and a Heterosporium species. 1-Corydalmine significantly inhibited spore germination of all the fungi at 100 to 1500 ppm. It was effective against all the fungi at 1500 ppm. C. lunata was highly sensitive to this chemical even at 250 ppm.

• Mycobiology
• /
• v.35 no.3
• /
• pp.157-158
• /
• 2007

The alkaloid fuyuziphine was isolated from the whole plant of Fumaria indica. It had inhibitive effect against spore germination of some plant pathogenic fungi (Collectotrichum sp., C. gloeosporioides, C. falcatum, Curvularia maculans, C. lunata, Erysiphe cichoracearum, Helminthosporium pennisetti, Oidium erysiphoides, Ustilago cynodontis, Alternaria chieranthi, A. mel-ongenae, A. brassicicola and A. solam). Curvularia lunata, Oidium erysiphoides, Alternaria brassicicola and A. solani did not germinate at 750 and 1000 ppm and Colletotrichum gloeosporioides, C. falcatum, Curvularia maculans were inhibited at 1000 ppm for 24 hr incubation. Germination of most fungi was significantly inhibited at $100{\sim}750ppm$.

• Mycobiology
• /
• v.33 no.2
• /
• pp.97-103
• /
• 2005

Crude extracts and active principles from medicinal plants have shown potential role in controlling plant diseases in glasshouses as well as in fields as one of the safest and ecofriendly methods. The effect of nor-securinine (an alkaloid) isolated from Phyllanthus amarus has been seen against spore germination of some fungi (Alternaria brassicae, A. solani, Curvularia pennisetti, Curvularia sp., Erysiphe pisi, Helminthosporium frumentacei) as well as pea powdery mildew (Erysiphe pisi) under glasshouse conditions. The sensitivity of fungi to nor-securinine varied considerably. Nor-securinine was effective against most of the fungi. H. frumentacei was more sensitive even at the lowest concentration ($1,000\;{\mu}g/ml$). Likewise conidia of E. pisi were also inhibited in partially or completely appressorium formation. Pre-inoculation treatment showed greater efficacy than post-inoculation in inhibiting powdery mildew development on pea plants in a glasshouse. Maximum inhibition occurred at $2000\;{\mu}g/ml$.

• Mycobiology
• /
• v.30 no.1
• /
• pp.55-56
• /
• 2002

The 4',7-dimethoxyisoflavone was isolated from the leaves of Albizzia lebbeck for the first time. This flavonoid showed antifungal activity against some plant pathogenic fungi tested in vitro, e.g., Alternaria melongenae, A. brassicicola, A. brassicae, Curvularia maculans, C. pallescens, C. lunata, Curvularia species, Colletotrichum species, Helminthosporium penniseti and H. speciferum. The sensitivity of different fungi to this chemical varied considerably. A. brassicae was most sensitive as complete inhibition of germination was observed in all the concentrations(100 to 1000 ppm) of the chemical. Similar effect on H. speciferum and Curvularia species was also recorded at 500 ppm, whereas H. penniseti did not germinate at 250 ppm. A. melongenae and A. brassicicola also did not germinate at 1000 ppm while 750 ppm was inhibitory to C. lunata and C. maculans. Germination in almost all fungi was significantly inhibited at each concentration in comparison to control except Curvularia sp. and H. speciferum. Use of 4',7-dimethoxyisoflavone to control some plant diseases under field conditions has been suggested.