• Korean Journal of Weed Science
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• v.17 no.4
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• pp.407-412
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• 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 CROP SCIENCE
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• v.53 no.1
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• pp.70-74
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• 2008

To determine an optimum harvest time for chinese milk vetch (CMV) seed production, the seeds were harvested at 4 times, according to 25, 30, 35, and 40 day after flowering (DAF), in Miryang, southern part of Korea. CMV plants were manually harvested at each time and seed threshing was done by rice threshing machine. Seed yield, 1,000-seed weight, germinability, and hard coat ratio were investigated. Seed yield was the highest, 53.9 kg/300 kg by dry weight (DW) of CMV plant, at 35 DAF. 1,000-seed weight increased according to seed harvest time from 25 DAF to 40 DAF when it was 3.10 g. The germination ratios of seeds harvested at 4 times were not significantly different when the seeds stored until August 1. In case of long period of CMV seeds stored, the seeds harvested later showed higher germination rate. On the other hand, because the hard coat ratio causing germination inhibition was declined with an increase of storage period, it was higher in the seeds harvested later. There was no difference among the seeds harvested at 4 times at October 1. In conclusion, it was presumed that an optimum harvest time for CMV seed production should be at 35 DAF considering seed yield, weight and germinability.

• Korean Journal of Plant Resources
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• v.12 no.1
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• pp.20-26
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• 1999

To investigate phytotoxic substances in Equisetum arvense, the aqueous extracts(25 and 8$0^{\circ}C$) or the freeze-drying matter from aqueous extracts($25^{\circ}C$) of E. arvense were tested at different concentrations for biological activities on callus induction and growth, seed germination, seedling growth and antibacterial function. Callus induction and growth of Oryza sativa and Brassica campestris ssp. pekinensis were inhibited by the aqueous extracts at 8$0^{\circ}C$ than at $25^{\circ}C$ and the higher concentrations. Callus growth of four receptor species was inhibited in order of Platycodon grandiflorum, Sesamum indicum, Brassica campestris ssp. pekinensis and Oryza sativa. Seed germination of Ο. sativa, S. indicum, and B. campestris ssp. pekinensis was not affected at low concentration, but it was proportionally inhibited by the higher concentrations. The greatest inhibition of seed germination was 28.3% compared to control, when 2,000$\mu\textrm{g}$/ml of freeze-drying matter was applied to B. campestris ssp. pekinensis. Shoot growth was stimulated by 500$\mu\textrm{g}$/ml of freeze-drying matter, but it was inhibited by the higher concentrations. Root growth was significantly inhibited compare to control at all concentrations. Antibacterial activity of freeze-drying matter didn't showed against Xantomonas oryzae and Eschrichia coli, but a small clear zone was formed by 500$\mu\textrm{g}$ of freeze-drying matter against Erwinia carotovora ssp. carotovora.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.324-328
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• 2008

One hundred-eighty extracts of soil collected from ginseng (Panax ginseng C.A. Meyer) fields were subjected to lettuce germination test, electrolyte leakage, cell viability and antioxidant enzyme activity test. Regardless of various cultivation periods, there was no significant difference in soil pH, the content of organic matter and available phosphate in ginseng fields. Based on lettuce seed germination test, six soil extracts showing inhibition of germination and/or seedling growth were selected for further study. Selected soil extracts markedly inhibited cell viability of ginseng cultured cells but leakage of electrolytes were not affected by the treatment. Enzyme activity of superoxide dimutase in ginseng cultured cells was not affected by the treatment with the soil extracts. However, those of peroxidase and catalase were significantly inhibited by the treatment with soil extracts which showed inhibition of lettuce seed germination and seedling growth.

• 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.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.681-684
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• 2001

Pseudomonas sp. F721 isolated from soil produced a substance related in seeds germination inhibition. Addition of phytohormone, and GA (gibberellin acid) in the culture broth elevated production of the germination inhibition substance. The production of the substance was optimized in the culture conditions of $35^{\circ}C$, pH 9.0, 150 rpm, 48 hr, glucose 0.5% (w/v), and innoculation ratio 1.0% (v/v). The physical and chemical stability of the substance in the variety of pH ranging from 2.0 to 12.0 and from freezing to $100^{\circ}C$ were shown. The germination inhibition substance suppressed 90% of germination compared with that of the control experiment in a few days.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.277-282
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• 2006

For searching the natural herbicide-components, the seed germination and seedling growth of receptor plant species (Brassica campestris, Sesamum indicum, Perilla frutescens and Echinochloa crus-galli) were investigated in four solvent-extracts extracted from Coptis chinensis Franch. The seed germination of receptor plant species was largely inhibited in 2,000 ppm of ethyl acetate compared to the control, and it was inhibited in order of P. frutescens, B. campestris, E. crux-galli, and S. indicum. In seedling growth, the shoot and root elongations of receptor plant species were inhibited in order of S. indicum, P. frutescens, B. campostris, and E. crus-galli. Root elongation was remarkably reduced in order of $H_2O$, butyl alcohol, and hexane, ethyl acetate extracts. Of four receptor plant species, seed germination and seedling growth of B. campestris and S. indicum showed the species-specific reaction to the solvent-extracts extracted from C. chinemis. $H_2O$ extract had a natural herbicide potential to the seed germination or root elongation in B. campestris and S. indicum. The result can be provided a basic data f3r the development of natural herbicide.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.641-645
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• 2007

We conducted a seed germination screening under saline conditions to identify salt tolerance(sto) mutants with ethyl methane sulfonate(EMS) mutagenesis seed pool. During the screening, we identified three mutant lines that seemed to confer elevated salt tolerance in high concentrations of NaCl. At 175 mM NaCl, germination rate of sto42-14 mutant(one of the EMS salt tolerance mutants) was 7-fold higher than that of wild-type plants. Interestingly, sto42-14 mutant exhibited insensitivity to high glucose concentration and growth inhibition to gibberellin. Our results suggest that sto42-14 is involved in salt stress tolerance as well as in glucose and gibberellin response in Arabidopsis.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.189-196
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• 1993

Allelopathic inhibition by substance(s) originated from sicklepod(Cassia tora L.) seed on germination of other plant seeds, was confirmed and used to elucidate general mechanism of allelopathy which was occurred widly in natural and/or agricultural ecosystems. The mechanism was deduced from changes in water contents, ${\alpha}$-amylase activities, protease activities, concentrations of abscisic acid and total phenolic compounds during germination of rice and radish seeds treated with water-soluble extracts of sicklepod seeds. The results obtained were summarized as follows. 1. The % germinations of radish, rice, lettuce, barley seeds were decreased by substances originated from crushed sicklepod seeds. 2. By the treatment of water-soluble extracts of sicklepod seeds, the inhibition of germination of radish seeds was occured with the sequential phenomena of increase of protease activity(synthesis), decrease of water content and increase of total phenolic compounds content. 3. In rice, the inhibition of seed germination by the water-slouble extracts of sicklepod seeds was related to increase of abscisic acid concentration and then decrease of ${\alpha}$-amylase activity(synthesis).

• The Korean Journal of Ecology
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• v.17 no.1
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• pp.23-35
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• 1994

To investigate phytotoxic substances in Artemisia argyi, the donor plant, and their biological activities, seed germination and seedling growth of receptor plants such as Arundinella hirta, Echinochloa crus-galli, Rumex crispus and Lactuca sativa were examined at different concentrations of aqueous extracts of the donor plant. Germination of four receptor species was inhibited by the extracts, while seedling growth was decreased to a lesser degree than in the germintion test. Germination, seedling growth and dry weight growth of Achyranthes japonica grown in pot were proportionally inhibited by the extracts. Volatile substances emitted from A, argi plant caused slight inhibition in the germination and seedling growth of the receptor species. Essential oil of the plant extracted by Karlsruker's apparatus inhibited growth of microorganisms and callus growth of Pinellia ternata and Oryza sativa. The GC /MS method was employed for analysis and identification of allelochemicals from A. argyi leaves. Sixty-one chemical substances such as a-pinene, camphene, 1. 8-cineol, etc. were identified from essential oil of A. argyi. The results of this experiment on seed germination, seedling growth, microorganism culture and tissue culture indicated that naturally occurring chemical substances from A. argyi would be responsible for the growth inhibition of plants studied.