• The Korean Journal of Ecology
• /
• v.24 no.1
• /
• pp.67-73
• /
• 2001

The allelochemicals from aqueous extracts of A. artemisiifolia var. elatior leaves and roots were analyzed and 60 compounds in the leaf and 53 compounds in the roots were inspected. The main compounds were acids,. especially phenolic acids and some non-acids. The total amount of compounds in the aqueous extracts of A. artemisiifolia var. elatior leaves was higher than in the roots. The aqueous extracts had much high inhibiting effects on the germination and seedling elongation of selected plants. In both cases, the inhibiting effects were very different with different selected plants and increased significantly as the concentration of aqueous extracts increased. Capsicum annum, Achyranthes japonica, and Oenothera odorta plants were suffered more significant inhibition effects than Raphnus sativus, Cucumis sativus, Brassica camperstris plants. Aqueous extracts from leaves had slightly higher inhibition effects than the aqueous extracts from the roots.

• Korean Journal of Weed Science
• /
• v.9 no.2
• /
• pp.149-153
• /
• 1989

Volatile terpenes responsible for allelopathic activity in four weed species were identified using gas chromatography (GC) and GC-mass spectrometry. Artemisia asiatica Nakai contained 26 volatile terpenes, consisting of 16 monoterpenes and 10 sesquiterpenes, whereas there were only four terpenes in Trifolium repens L. and three terpenes each in Portulaca oleracea L. and Capsella bursa-pastoris (L,) Medik. Suspected allelochemics were ${\alpha}$-phellandrene, 1,8-cineole, limonene, ${\alpha}$-pinene, borneol, selinene, and caryophyllene in A. asiatica, ${\alpha}$-pinene and ${\beta}$-caryophyllene in T. repens, and ${\alpha}$-pinene in C. bursapastoris. No these compounds were found in P. oleracea.

• Korean Journal of Weed Science
• /
• v.17 no.4
• /
• pp.407-412
• /
• 1997

Allelopathic activity of methanol extract from medicinal plants was determined based on the inhibition of germination, shoot and root length of Echinochloa crus-galli. The response was depended on the source of extracts and concentrations. Of the 20 test plants tested, Cnidium officinale showed most inhibition according to germination, shoot and root length of E. crus-galli. Based on the plant parts, the root extract of C. officinale had more inhibitory effect on E. crus-galli than the stem+leaf extract. Phytotoxic effects of the root extract on E. crus-galli showed 75% inhibition of seed germination, 95% inhibition of shoot growth, and 100% inhibition of root growth at the concentration of 1g/petridish. Sequential partitioning of root extract with organic solvents with increasing polarity showed that the ethylacetate fraction had the greatest inhibitory effect on E. crus-galli. Germination was not inhibited at any rate of ethylacetate fraction but shoot and root growth, were significantly inhibited even at 2mg/petridish. This indicates that the most toxic phytotoxin present in the root extract may be moderate polar compound.

• Korean Journal of Organic Agriculture
• /
• v.16 no.1
• /
• pp.127-142
• /
• 2008

This study was carried out to germination characteristics by temperature conditions and allelopathic effects of aqueous extracts on Amaranthus spinosus L. in order to investigate the competitive dominant in plant ecosystem and possibility application of natural herbicide. A. spinosus L. sprouted after 24 hour from seeding in $30{\sim}45^{\circ}C$ treatment. The germination ratio of A. spinosus L. was the highest estimated at 63.3(${\pm}2.9$)% in $40^{\circ}C$ treatment, followed by 33.3(${\pm}2.9$)% in $35^{\circ}C$, 1.7(${\pm}2.9$)% in $30^{\circ}C$ and 5.0(${\pm}0.0$)% in $45^{\circ}C$ treatment. It was generally decreased the Relative Germination Ratio(RGR), the Relative Elongation Ratio(RER), the Relative Fresh weight Ratio(RFR) of receptor plants by the aqueous extracts of concentration of A. spinosus L. but it was differently inhibited the kind of receptor plant species. And it was different effected among growing regions that aqueous extracts of concentration of A. spinosus L. inhibited more root than shoot. The total phenolic compounds content of A. spinosus L. was decreased gradually middle, first and last of growth stage, and gradually decreased to leaves, roots and stems. We think that A. spinosus L. appeared high germination ratio at a short period and showed allelopathic effects on other plants. Therefore A. spinosus. L. hold the competitive dominant of plant ecosystem in Jeju Island and possibility application of natural herbicide.

• The Korean Journal of Ecology
• /
• v.12 no.3
• /
• pp.161-170
• /
• 1989

To verify allelopathic effects of Artemisia princeps var. orientalis, a number of laboratory experiments have been performed. Aqueous extracts of leaves, stems and roots of the above species inhibited the seed germination and seedling growth of experimental species, receptor plants. In general, the higher was the concentration of the extracts, the lower was the germination and the growth ratio. Volatile substances released from leaves of the donor plants also inhibited the seed germination and the radicle elongation of receptor plants. Therefore, to find out the inhibitory substances emitted from the wormwood, gas chromatography was employed. As a result of the analysis, 17 KDICical substances were isolated from the leaves and most of them were identified as phenolic compounds.

• Journal of Plant Biology
• /
• v.30 no.1
• /
• pp.59-67
• /
• 1987

To verify allelopathic effect of tomato plants a number of labovatory experiments, seed germination and seedling growth with aqueous extracts and leachates form the tomato plants, have performed. Germination percentage of the tested species was decreased by treatment with leaf, stem and root extracts as extracting time elapses. The leaf extract more inhibits the germination of the seeds than both stem and root extracts. Leachate collected from the tomato plants decreases as much as 50% of the growths in elongation as well as dry weight of seedlings of lettuce and egg plant. It is observed that with a paired-plants grown in U tube pot the tomato roots have excreted allelochemicals to inhibit the growth of the tested species and volatile substances from the tomato plants have suppressed to dry weights of lettuce, to elongation and dry weights of grapevine planted near the tomato plants.

• The Korean Journal of Ecology
• /
• v.20 no.3
• /
• pp.181-189
• /
• 1997

Phenolic compounds from 7 species of naturalized invader species and Korean wild plants were analyzed by high performance liquid chromatography. Eleven phenolic compounds including benzoic acid were identified. The extract of naturalized plants was significantly more inhibitory to seed germination and seedling growth of the both naturalized and Korean wild plants. The content of total phenolic compounds in each extract were 43.5 mg/l in Ailanthus altissima as the maximum amount and 25.5 mg/l in Phytolacca americana as the minimum. Phytotoxic substances of ethanol extracts was investigated for antifungal activity against 23 selected fungus species. The antifungal activity of Phytolacca americana showed the greatest clear zone of 23 mm in Aspergillus awamori and its activity had an effect against 6 fungus species. Ailanthus altissima formed the greatest clear zone of 26 mm in Erwinia carotovora sub. sp. carotovora and had an effect agsinst 2 fungus species.

• The Korean Journal of Ecology
• /
• v.14 no.2
• /
• pp.121-135
• /
• 1991

A number of laboratory experimentes have performed to elucidate water-soluble of volatile substances from wormwood plant(artemisia princeps var. orientalis) as growth inhibitor or phytotoxicant. in germination tests with aqueous extracts of leaves, stems and roots of the wormwood plants, most tested species showed that relative germination ratio was inversely proportional to comcentration of the extracats. and seedling elongation and dry weight of the species were heavily inhibited with the extracts, incubated leaves, volatile substances of the leaves and soil underneath wormwood plants. gas Chromatography was employed to find out possible phytotoxic substances or growth inhibitors of wormwood leaves. ten substantes have isolated, and most of them were identified as terpenoids.

• Korean Journal of Ecology and Environment
• /
• v.40 no.4
• /
• pp.520-526
• /
• 2007

To select submerged macrophytes to suppress growth of Microcystis aeruginosa through releasing allelochemicals, we conducted growth experiments with water from patches of submerged macrophytes and with aqueous extracts of those submerged macrophytes. In the first experiment, growth rates of M. aeruginosa decreased as biomass of Myriophyllum spicatum and Hydrilla verticillata increased. In the second experiment, M. aeruginosa showed approximately 50% growth reduction with extracts from M. spicatum and 24% reduction with extracts from Ottelia alismoides. Both M. aeruginosa growth experiments with water and plant extracts suggest that M. spicatum would be the best candidate to reduce M. aeruginosa growth.

• The Korean Journal of Ecology
• /
• v.21 no.2
• /
• pp.133-137
• /
• 1998

Well grown trees of ficus bengalensis produce one or more potential inhibitors of seed germination and seedling growth. The aqueous extract of ficus leaf and bark enhanced the shoot length aqueous leaf extract of F. bengalensis. Bark extract of F. bengalensis inhibited the shoot length and root length of the plant at high concentration. Both the bark and leaf extract inhibited the seed germination. The postemergence and preemergence treatment of bark and leaf extract of F. bengalensis reduced the shoot biomass. The result suggest that F. bengalensis may have potential allelochemicals which may be developed as natural herbicides.