• Korean Journal of Weed Science
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• v.18 no.3
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• pp.214-224
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• 1998

This study was conducted to develop labor and chemical cultural practice improvement for weed control in ginseng field. Five crop species were screened in vitro and three crop extracts were sprayed in the test allelopathic effect for weed species. Methyl alcohol extracts of rice, oat, rye and wheat straw showed inhibitory effect on the germination of six weed species, Amaranthus retroflexus, Chenopodium album, Arthraxon hispidus, Digitaria adscendens, Echinochloa crus-galli, and Setaria viridis. Especially, extract of oat straw was most effective to inhibit the germination of six weed species tested. Also, spraying the extract solution of rice, rye and wheat straw was effective to inhibit the growth of weeds in ginseng field. Ginseng root length, diameter, fresh and dry weight in extract spraying plot were higher than those of non-treatment plot.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.231-236
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• 2007

Differentially expressed genes(DEG) were identified in a rice variety, Sathi, an indica type showing high allelopathic potential against barnyardgrass(Echinochloa crus-galli(L.) Beauv. var. frumentaceae). Rice plants were grown with and without barnyardgrass and total RNA was extracted from rice leaves at 45 days after seeding. DEG full-screening was performed by $GeneFishing^{TM}$ method. The differentially expressed bands were re-amplified and sequenced, then analyzed by Basic Local Alignment Search Tool(BLAST) searching for homology sequence identification. Gel electrophoresis showed nine possible genes associated with allelopathic potential in Sathi, six genes(namely DEG-1, 4, 5, 7, 8, and 9) showed higher expression, and three genes(DEG-2, 3 and 6) showed lower expression as compared to the control. cDNA sequence analysis showed that DEG-7 and DEG-9 had the same sequence. From RT PCR results, DEG-6 and DEG-7 were considered as true DEG, whereas DEG-1, 2, 3, 4, 5, and 8 were considered as putative DEG. Results from blast-n and blast-x search suggested that DEG-1 is homologous to a gene for S-adenosylmethionine synthetase, DEG-2 is homologous to a chloroplast gene for ribulose 1,5-bisphosphate carboxylase large subunit, DEG-8 is homologous to oxysterol-binding protein with an 85.7% sequence similarity, DEG-5 is homologous to histone 2B protein with a 47.9% sequence similarity, DEG-6 is homologous to nicotineamine aminotransferase with a 33.1% sequence similarity, DEG-3 has 98.8% similarity with nucleotides sequence that has 33.1% similarity with oxygen evolving complex protein in photosystem II, DEG-7 is homologous to nucleotides sequence that may relate with putative serin/threonine protein kinase and putative transposable element, and DEG-4 has 98.8% similarity with nucleotides sequence for an unknown protein.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.421-430
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• 1997

This experiment was conducted to detect the presence of allelopathic substances in the leaves of Ginkgo biloba L. Water extracts from G. biloba leaves which collected at different season markedly inhibited the germination and growth of O. sativa, E. crus-galli, D. sanguinalis, and L. sativa, indicating the presence of biological substances. Linolenic and palmitic acid were the major fatty acids of G. biloba leaves. The biochemical substances such as salicylic arid, p-coumaric acid, catechol, hydroquinone, orchinol, ferulic acid, phloroglucinol, and umbelliferone etc., belonging to the phenolic, compounds were, detected in a large amount, which may be responsible for exhibition inhibitory effects. The common phenolic compounds were detected in the early-harvested and late-harvested G. biloba leaves were salicylic and p-coumaric acid. All these compounds were related to the allelopathic activities in G. biloba leaves.

• The Korean Journal of Ecology
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• v.22 no.1
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• pp.59-63
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• 1999

To verify allelopathic effects, seed germination and seedling growth test, chemical analysis and bioassay of selected species were carried out with naturally occurring chemicals of Artemisia capillaris. Seed germination ratio of Calamagrostis arundinacea. Youngia denticulata and Lactuca indica var. laciniata showed decrease in proportion to increase in aqueous extracts concentration of A. capillaris. while that of Cosmos bipinnatus and Leonurus sibiricus did not. However, dry weight growth of selected species treated with the same extracts as the above experiment was inhibited remarkably compared to the germination test. In the test at different concentrations of essential oil from A. capillaris, seedling growth of A. princeps var. orientalis and Plantago asiatica was suppressed according to the concentration of the essential oil, and root growth of the selected species was more inhibitory than that of shoot growth. Thirty-six chemical compounds were identified from A. capillaris plant by gas chromatography. Seven compounds out of 36 were bioassayed, and terpinen-4-ol was the most toxic among the tested substances.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.17-22
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• 1988

Inhibitory effect of L. leptolepis fallen leaf extracts on the germination of Pinus densiflora, ${\times}$ Pinus rigitaeda, Pinus rigida, Pinus thunbergii and Larix leptolepis was investigated. Germination of those seeds in culture room and in pot at field showed the highly significant inhibitory effects by the aqueous extracts from L. leptolepis fallen leaves. Among them L. leptolepis was the most severely inhibited by the aqueous extracts used. To identify allelopathic substances, thin-layer chromatography was employed. Gallic, ferulic, t-cinnamic and vanillic acids were identified from fallen leaves of L. leptolepis. From the results, it is assumed that autotoxicity of L. leptolepis may act as inhibitory factors on germination of the species in natural stands.

• The Korean Journal of Ecology
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• v.28 no.3
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• pp.135-139
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• 2005

This study was carried out to find the allelopathic effect of volatile materials released from Eupatorium rugosum. The GC method was employed for analysis of volatile materials from E. rugosum and 49 chemical substances were identified such as $\beta$-caryophyllene, $\alpha$-terpinenol, chamazulene, bornyl acetate, $\alpha$-pinene, etc. including unidentified three chemicals. Germination test in Phaseolus radiatus was done to find the inhibition effect of volatile materials using some chemicals which were proved to be important component or much amounts ones in E. rugosum. It was strongly inhibited by linalool and terpinen-4-ol. Seedling elongation and radicle growth of that were proportionally inhibited by the concentration of the essential oil, especially $\alpha$-pinene and bornyl acetate. Biomass of receptor plant was slightly decreased more than 58 ${\mu}l$ of the extract in case of $\alpha$-pinene, while it was decreased more than 19 ${\mu}l$ of that in bornyl acetate but it was shown non-significant. From the above results, it was found that volatile materials from E. rugosum showed a allelopathic effect and also $\alpha$-pinene, bornyl acetate, linalool and terpinen-4-ol used in bioassay were some of major allelochemicals in germination inhibition and especially linalool and terpinen-4-ol are prominent effect on growth inhibition of other plant.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.11-19
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• 2003

Allelopathic effects of black locust(Robinia pseudoacacia L.) was evaluated through germination tests using 13 different species including R. pseudoacacia itself. The water extract from leaf or root of R. pseudoacacia was separately tested. Seed germination of several species was inhibited in the presence of leaf or root extract, although the level of germination was in a wide range depending on the species. Seed germination of R. pseudoacacia was suppressed by 30 % in its leaf extract. Among tested tree species, Hibiscus syriacus and Alnus frma showed significantly inhibited germination in the root extracts whereas Thuja orientalis exhibited germination inhibition in the leaf extract. HPLC was carried out to identify allelochemicals in extracts of leaf and root using eight authentic phenolic compounds that are known to be responsible for allelopathy. The major phenolic compounds occupying about 40 % of total phenolic acids were gentisic acid in leaves and vanillic acid and syringic acid in roots. The leaves contained 7 times more phenolic acids than the roots. Among 8 tested phenolic compounds vanillin was detected only in roots and coumaric acid in leaves. Consequently, 3 out of 13 species showed significantly inhibited germination due to leaf or root extract. This germination test indicates that the inhibitory allelopathic effect by R. pseudoacacia is caused by chemical interaction not by nutritional competition and that the allelochermicals of black locust act species-specifically. No specific influence of the total amount of phenolic compounds on the allelopathic inhibitory germination and the synergic effect by each phenolic compound may play a role for the allelopathic effect by R. pseudoacacia.

• Proceedings of the Plant Resources Society of Korea Conference
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• v.18 no.1
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• pp.139-139
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.260-261
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• 2005

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.159.3-160
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• 2001

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