• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.11-18
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• 2000

This study was conducted to establish an efficient screening method of membrane-disrupting herbicides, based on the result that membrane leakage leading to evolution of carbonyl compounds and aldehydes could be colorimetrically assessed by formation of stable chromophores with MBTH and ferric chloride. Assay conditions including plant material, light intensity, irradiation time, concentrations of reagents for colorization, and reaction time were optimized, and activities of different types of known herbicides were investigated with cucumber cotyledon discs. That result indicated that this assay was sensitive to membrane-disrupting herbicides, such as protoporphyrinogen oxidase inhibitors (acifluorfen, oxyfluorfen, oxadiazon) and an electron interceptor from photosystem I(paraquat). With seven compounds newly synthesized, highly positive correlation was observed between herbicidal activities measured by greenhouse bioassay and MBTH method. Because only a single disc(4 mm diameter) from cucumber cotyledon in 60 ${\mu}L$ of incubation solution was required to assay, a large number of herbicides could be tested simultaneously using 96-well microtitre plates. But the assay efficiency is not likely to significantly increase because of the boiling step during the reaction.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.18-20
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• 2000

Methanol extracts of nine native plants(Teraxacum platycerpum leaf, Pinus densiflora leaf, Artemisia prinseps, leaf, Allium tuberosum leaf, Cassia obtussifolia, whole plant, Sophora angestifolia root, Stemonae sessilifolia root, Lonicera japonica, stem, leaf, flower, and Clivia miniata leaf were tested for repellent activity against Aedes albopictus and Blateria germanica. The extracts of P. densiflora, T. platycerpum, A. tuberosum and L. japonica (flower) exhibited excellent repellent activity against A. albopictus, while only L. japonica (leaf) had some good activity against B. germanica.