• The Korean Journal of Ecology
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• v.20 no.4
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• pp.233-238
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• 1997

To evaluate allelopathic effect of volatile chemicals and phytohormones, seed germination and seedling growth test of Lactuca sativa have performed in laboratory experiments. Among used chemicals terpienen-4-ol was the most inhibitory to seed germination of lettuce. ABA and GA inhibited seed germination at $5{\times}10^{-6}M$ concentration but promoted germination at $2.5{\times}10^{-5}M$ and $5{\times}10^{-5}M$. ABA and GA alleviated volatile chemical-induced inhibition of seed germination and seedling elongation of lettuce.

• The Korean Journal of Ecology
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• v.21 no.2
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• pp.151-156
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• 1998

the phytotoxic effects of volatile substances emitted from the tomato plant (Lycopersicon esculentum) on receptor plants such as Bidens bipinnata, Plantago asiatica, Lactuca sativa, Eragrositis ferruginea and Achyranthes japonica were investigated. Bolatile substances from the leaves inhibited seedling growth of receptor plants in the laboratory tests. The inhibition response varied with the concentration of compounds. To identify the phytotoxic compounds from tomato plant a GC/MS method was employed. Forth compounds, such as trans-2-hexeal, linalool, phenylacetaldehyde, methlsalicylic acid and tetradecanaic acid were identified from the essential oil of tomato plants. The findings suggest that the tomato plant may have allelopathic potential.

• Proceedings of the Korean Society of Crop Science Conference
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• 1999.05a
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• pp.118-119
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• 1999

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.1-6
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• 1999

This study was conducted to detect the allelopathic effect of water and ethanol extracts from 4 plant species (Lactuca sativa L., Ambrosia elatior L., Oenothenra odorata Jasp., Ginkgo biloba L.) on germination and growth of lettuce seeds. A little bit higher inhibitory effect was obtained in ethanol extracts rather than water extracts. Allelopathic effects varied in the source of extracts and concentrations of 4 plant species and the highest allelopathic effect appeared in 10% solution, regardless of plant species.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.271-278
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• 2011

The allelopathic effects of Lantana camara L. (Family:Verbenaceae) on germination and seedling establishment of some agricultural crops and weed species have been identified. Aqueous extracts of dry leaves and contaminated soil where L. camara is grown were used to verify allelopathic effect on seed germination of five bioassay species; Raphanus sativas, Capsicum annum, Lycopersicum esculantem, Crotalaria juncia and Chromoleana odorata. Fifty seeds from each bioassay species were placed in a petri dish containing leaf extracts or contaminated soil, and seed germination were examined after 3 days. The plant house experiments were carried out to evaluate the impact of L. camara contaminated soil and leaf debris using L. esculantem as the indicator plant. Seed germination of L. esculentem, C. junica and Capsicum annum was significantly inhibited by L. camara contaminated soil. However, the degree of inhibition varied among the bioassay species. The aqueous extract of dry leaves of L. camara was highly phytotoxic and it significantly reduced seed germination of all bioassay species. There was a decline in plant height, leaf area and shoot dry weight of tomato only in early growth stages when grown in L. camara contaminated soils. However, incorporation of leaf debris into soil affected the vegetative growth of tomato in early stages when the leaf debris concentration was increased. Growth recovered at the latter part of the life cycle. On the basis of these results it can be concluded that the allelochemicals in L. camara contaminated soils are harmful to the seed germination of crop species. The adverse effect was present only during the early growth stages and it did not suppress the latter part of the plant growth. These responses are attributed to allelopathic effects which need confirmation under field conditions.

• Korean Journal of Weed Science
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• v.11 no.2
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• pp.122-127
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• 1991

The allelopathic effects of rice and barley straws on lettuce germination and weed growth were investigated. The grinded straw of rice significantly inhibited lettuce germination. Both rice and barley straws decreased weed growth when they were used as a mulch in the field. Rice straw mulch applied with 500g/$m^2$ and 700g/$m^2$ decreased dry weight of Alopecurus aequalis more than 35%. Barley straw mulch applied with 200 g/$m^2$ inhibited dry weight of Echinochloa curs-galli and Digitaris sanguinalis, while the straw applied with 300 g/$m^2$ decreased those by 97%.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.65-70
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• 2002

This study was conducted to investigate allelopathic potential of various crosses of rice cultivars using their inhibitory effect on barnyardgrass growth under field conditions, and to determine PAL activity and phenolic compounds involved in phenylpropanoid pathway from selected crosses of rice cultivars. Under field conditions, Kouketsumochi, Woo co chin yu possessed higher allelopathic potential inhibiting over 90% of barnyardgrass growth. Crosses of Kouketsumochi/Woo co chin yu, Dongjinbeyo/Kouketsumochi, Dongjinbeyo/Woo co chin yu showed over 80% inhibitory effects on barnyardgrass growth. The highest PAL activity, $63.46{\mu}kats/kg$ proteins was detected in Kouketsumochi which is the most important enzyme in phenylpropanoid pathway and also higher PAL activity in crosses with Kouketsumochi. Content of cinnamate was $2.64{\mu}g/g$ f.w. in Kouketsumochi which was 2 to 5 times higher than other rice cultivars tested, indicating that higher PAL activity resulted in more cinnamate. The similar trends in cinnamate content and PAL activity were observed in crosses of rice cultivars with Kouketsumochi.

• Journal of Plant Biology
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• v.34 no.2
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• pp.93-100
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• 1991

Walnut (Juglans regia L.) is a common cultivated and wild deciduous tree in the temperate regions of Pakistan and elsewhere. A bare or poor understorey of wild or cultivated species is frequently observed beneath and around it. Soil analysis indicated insignificant differences in nutrient status of soils taken from areas with or without walnut influence. Field investigations revealed that the height, shoot, fresh and dry weight of potato, turnip, corn and bean significantly decreased in the walnut-influenced parts of the field compared to their counter-parts in the same field but without walnut influence. Aqueous extracts from various parts, shoot litter, natural rain leachates and soil collected from beneath walnut significantly reduced the germination, early seedling growth, fresh and dry weight, and moisture contents of corn, turnip and bean in various laboratory experiments. Ferulic, p-coumaric, caffeic, vanillic, jJ-hydroxybenzoic, chlorogenic and gallic acid were identified as the possible allelopathic substances in the aquous extracts and rain leachates of the walnut tree. The findings suggest that the observed poor growth of crops is due to allelopathic effects of walnut.walnut.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.149-155
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• 2000

The allelopathic effects of Artemisia lavandulaefolia were studied using several test plants and microbes. Aqueous extracts and volatile compounds of A. lavandulaefolia inhibited seed germination, seedling and root growth of the test species such as Achyranthes japonica. Lactuca sativa, Artemisia princeps var. orientalis. Oenothera odorata, Plantago asiatica. Aster yomena, Elsholtzia ciliata, and Raphanus sativus var. hortensis for. acanthiformis. The root growth of test species was more affected than shoot growth by allelochemicals of A. lavandulaefolia. Essential oil of A. lavandulaefolia had antibacterial and antifungal effects. However, the antimicrobial activity of the essential oil was dependent upon the microbial species and concentrations. Callus growth of Oryza sativa, Brassica campestris subsp. napus var. pekinensis and Achyranthes japonica was sensitive by the essential oil of A. lavandulaefolia. Twenty three chemicals were identified from A. lavandulaefolia essential oil by gas chromatography. Primary allelochemicals among them were 1, 8-cineole, 1-$\alpha$-terpineol, $\alpha$-terpinene. camphor, 2-buten-1-ol and azulene. We concluded that aqueous extract and essential oil of A. lavandulaefolia were responsible for allelopathic effects.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.102-102
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• 2017

In this study, QTL analysis of allelopathy was conducted. A total of 171 of F8 RILs developed from the cross between Nongan(low allelopathic cultivar) and Sathi(high allelopathic cultivar) were used . the performance of allelopathy were evaluated using 'ECAM(Equal Compartment Agar Method)', where the root length of lettuce cultivated with the RILs were measured. The distribution of the performance was followed as normal distribution. In order to identify the location of QTLs related to allelopathy, QTL-seq with BSA(Bulked-segregant analysis) was performed with 20 highest and 10 lowest RILs. As a result, Two Sliding window coordinate region of candidate QTLs were detected on Chr4 (5,050,001 - 14,800,000, 18,650,001 - 22,500,000), Chr8 (2,550,001 - 8,250,000, 21,150,001 - 26,800,000) and One region on Chr7 (1 - 3,300,000), Chr9 (1 - 13,300,000) respectively.