• Journal of Applied Biological Chemistry
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• v.44 no.3
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• pp.147-153
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• 2001

Methanol extracts from 51 fruits were tested for their fungicidal activities against six phytopathogenic fungi in a greenhouse. The efficacy varied with both the plant pathogen and fruit species used. At 10 and 5 mg/pot, methanol extracts of Poncirus trifoliata peel and seed gave over 80% control values against Pyricularia grisea, and strong fungicidal activities against Rhizoctonia solani were showed from the extracts of Citrus paradisi peel and Punica granatum leaf. In a test with Botrytis cinerea at 5 mg/pot, the extracts of C. sinensis seed and D. kaki leaf produced potent fungicidal activities, and the extracts of C. crenata peel and leaf, Ch. sinensis seed, P. trifoliata peel, and Z. jujuba leaf had strong fungicidal activities. At 5 mg/pot, strong fungicidal activities were produced in the extracts of P. trifoliata peel and seed against Phytophthora infestans and in the extracts of P. ussriensis var. macrostipes fruit and seed, C. crenata peel, C. crenata leaf, C. paradisi peel, P. trifoliata peel, P. granatum peel, and Z. jujuba leaf against Puccinia recondita. In a test with E. graminis, potent activities at 10 mg/pot were produced from the extracts of Ch. sinensis seed, C. sinensis seed, P. trifoliata leaf, P. ussriensis var. macrostipes fruit and seed, and Vitis vinifera seed. In the control effect of seven extracts against B. cinerea strains resistant to carbendazim, procymidone, and diethofencarb, extracts of C. crenata peel and leaf, Ch. sinensis seed, and P. trifoliata peel were highly effective against all strains of B. cinerea. Furthermore, potent fungicidal activities were produced from the extracts of C. sinensis seed and D. kaki leaf against the SSR, SRR, and RRS, and Z. jujuba leaf against the SSR and RRS strains. As a naturally occurring fungicide, these fruit-derived materials could be useful as new fungicidal products against phytopathogenic fungi.

• Mycobiology
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• v.41 no.4
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• pp.234-242
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• 2013

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.21-27
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• 1998

Methanol extracts from 25 leguminous seeds were tested for their fungicidal activities toward six phytopathogenic fungi, using whole plant test in a greenhouse. The efficacy varied with both the plant pathogen and legume species used. At 5 mg/pot, potent fungicidal activities were produced from extracts of Cassia obtusifolia, Glycine max var. solitae, G. max var. yagkong, G. max var. hooktae, Phaseolus multiflorus, P. radiatus var. aurea, and Vigna sinensis against Botrytis cinerea, Puccinia recondita, and Erysiphe graminis. These seed extracts were highly effective against three B. cinerea strains resistant to carbendazim, procymidone, and diethofencarb. All leguminous seed extracts revealed weak or no fungicidal effect against Rhizoctonia solani, Pyricularia grisea, and Phytophthora infestans. As a naturally occurring fungicide, leguminous seed-derived materials described could be useful as new fungicidal products against various plant diseases induced by phytopathogenic fungi.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.130-135
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• 2002

Species of Genus Trichoderma are commercially applied as biological control agents against fungal Pathogens. A powerful biocontrol agent, Trichoderma sp. SJG-99721 was isolated from 305 isolates by morphological characters, chitinase activities and antifungal activities against Phytophthora capsiei. The isolate was identified as Trichoderma harzianum from various features such as growth rate at $27^\circ{C}$, significant growth ratio of $27^\circ{C}$ to $17^\circ{C}$, amount of aerial mycelium, types of branching: system, and disposition patterns of phialide and phialospore. Trichoderma harzianum SJG-99721 have been shown to act as a powerful biological agent against fungal phytopathogens; Botrytis cinerea, Rhizoctonia solani, Phytophthora cryptogea, Phytophthora capsiei, Sclerotinia sclerotiorum, Mycoshaerella melonis, Alternaria sotani, Fusarium oxysporum, Collectotrichum gloesporioodes, Alternaria alternata, Phythium ultimum, Phytophthora drechsleri, Pyricularia grisea.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.20-28
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• 1999

Chloronicotinyl derivatives were synthesized by substitution of amino in 3-pyridylmethylamine with phosphite groups and their insecticidal and fungicidal activities were determined. At 500 ppm, compound 4 with methyl and butyl group in phosphonate and compound 5, 6, 7, and 8 with two butyl, 2,2,2-trifluorotehtyl, 2-ethylhexyl, phenyl, respectively, in phosphonate showed 90% insecticidal activities against brown plant-hopper (Nilaparvate lugens). These compounds showed, however, poor insecticidal activities against diamond-back moth (Plutella xylostella) and two-spotted spider mite (Tetranychus urticae) (<65%), suggesting that insecticidal activity of chloronicotinyl derivatives containing phosphorus moieties are species-dependent. Newly synthesized chloronicotinyl derivatives with halogen and/or heterocycle (compound $10{\sim}21$) did not show insecticidal activities. We also determined fungicidal activity of the synthesized chloronicotinyl derivatives against rice sheath blight (Pyricularia grisea), cucumber gray mold (Bortytis cinerea), tomato late blight (Phytophthora infestans), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Erysiphe graminis). Compound 10 with butyl and 4-nitrophenyl in phosphonate at 10 ppm showed 85% fungicidal activity against rice blast, suggesting that chloronicotinyl derivatives containing phosphorus moieties could be developed as a fungicidal agent of a novel chemical structure.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.24-31
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• 1998

Chemical derivative synthesis of ricinine, an active compound of Ricinus communis which showed high mortality against brown planthopper (Nilaparvata lugens), was performed to improve its pesticidal activity and the toxicity of 12 synthetic derivatives against major insect pests and phytopathogenic fungi were examined. Carbamate derivatives of ricinine could be synthesized from the precursor of ricinine, chloronorricinine and norricinine, whereas the derivatives were not synthesized from chlororicinic acid and ricinic acid having ketone group of pyridine ring. In organophosphates, reaction with oxon type of phosphate gave better yield than thiono type. Among the organophosphate derivatives of ricinine, thiono type of derivative structure gave $96.3%{\sim}100%$ mortality of the brown planthopper and the two-spotted spider mite (Tetranychus urticae) at 500 ${\mu}g/ml$ level. On the other hand, carbamate derivatives did not show insecticidal activity. In the fungicidal activity of ricinine derivatives, the derivative having amino radical at the 2 position of ricinine gave 85 to 100% of mycelium growth inhibition effect against ten major plant pathogens at the 200 ${\mu}g/ml$ level. In particular, the control value of the derivative on the rice blast (Pyricularia grisea) and barley powdery mildew (Erysiphe graminis) at the 250 ${\mu}g/ml$ level in vivo under greenhouse conditions was 92% and 96%, respectively.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.7-14
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• 2000

Methanol extracts from 21 grains were tested for fungicidal activities against six phytopathogenic fungi and for insecticidal activities toward five insect pests in a greenhouse. The efficacy varied with both the plant pathogen/insect pest and grain species used. Potent fungicidal activity at 5 mg/pot, were produced from extracts of Elymus sibiricus and Hordeum vulgare var. nudum against Pyricularia grisea and Erysiphe graminis and these of Sesamum indicum (W) and Triticum aestivum against Puccinia recondita and Erysiphe graminis. At 2,500 ppm, potent insecticidal activities were exhibited from the extracts of Fagopyrum esculentum against Myzus persicae and Ischaemum crassipes, and these of Oryzo sativa var. glutinosa, Panicum miliaceum, Setaria italica, Sorghum bicolor, and T. aestivum against Tetranychus urticae. All grain extracts revealed weak or no fungicidal and insecticidal effect against Phytophthora infestans, Plutella xylostella and Spodoptera litura. As a naturally occurring fungicide and insecticide, grain-derived materials described could be useful as new fungicidal and insecticidal products against phytopathogenic fungi and insect pests.

• Korean Journal of Breeding Science
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• v.51 no.4
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• pp.395-403
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• 2019

Rice blast caused by the fungus Magnaporthe grisea (anamorphic: Pyricularia oryzae) is an important disease in rice and development of resistant varieties to blast is one of the most important goals in rice breeding programs. A japonica rice variety, Palgong, has shown resistance to the Korean blast pathogen since it was developed in 1996. Nine blast resistance quantitative trait loci (QTLs) in Palgong alleles were identified on chromosomes 2, 4, 7, and 11. Four QTLs of qBn2.3, qBn4.2, qBn11.1, and qBn11.2 explained 28-56.7% of total phenotypic variation, while five QTLs of qBn2.2, qBn2.4, qBn4.1, qBn7.1, and qBn7.2 explained 9.7-18.8%. In a previous study, one to four resistance genes were located on the loci qBn2.2, qBn2.3, qBn4.2, qBn11.1, and qBn11.2, however, resistance genes were not located on the loci qBn2.4, qBn4.1, and qBn7.1. A major QTL, qBn11.2, explaining 56.7% of total phenotypic variation was related to the durable resistance of Palgong. Additionally, rice stripe virus resistance of Palgong was assumed to be based on the Stvb-i gene, which is located on a major QTL qBn11.2.