• The Korean Journal of Mycology
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• v.51 no.4
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• pp.405-410
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• 2023

Erysiphe chloranthi is the only powdery mildew species (Erysiphaceae) found on Chloranthus plants belonging to the family Chloranthaceae. This species has long been known to be present in Japan and Korea and is hence regarded as endemic to East Asia. Examination of seven Korean specimens revealed detailed morphological characteristics of the holomorph of this species. Short foot-cells of conidiophores are proposed as key characteristics that differ from related species. Sequences of the internal transcribed spacer regions and large subunit gene retrieved from four Korean samples confirm the phylogenetic position of this species within the Erysiphe aquilegiae complex. These data may help elucidate the identity of this species and clarify the ambiguity of the E. aquilegiae complex.

• 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.