• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.498-505
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• 2010

To evaluate the effectiveness of AMF on the growth of horticultural crops, we compared mycorrhizal and non-mycorrhizal plants, lettuce (Lactuca sativa L.), that were inoculated with AMF propagules. As compared to the AMF- seedlings, in AMF+ seedlings at 3 weeks after sowing, the number of leaves increased 9%, leaf fresh weight increased 59%, leaf area increased 58%, and leaf length and width increased 21-22%, and chlorophyll content increased 2%. Furthermore, at 9 weeks after sowing, compared to the AMF- plants, in lettuce plants inoculated with AMF at the sowing and transplanting stages, the number of leaves increased 21% and 18%, leaf fresh weight increased 51% and 41%, root fresh weight increased 56% and 47%, and chlorophyll content increased 18% and 19%, respectively. Further this experiment indicated that the growth responses of lettuce plants inoculated with AMF during transplanting were similar to those inoculated with AMF during sowing. The results imply that the AMF infection timepoint is not important. The P content in the leaves of lettuce plants inoculated with AMF during transplanting was significantly higher (217%) than that of leaves from lettuce plants not inoculated with AMF. In contrast, the P content of the leaves of lettuce plants inoculated with AMF during the sowing stage was similar to that of leaves of control lettuce plants. In this experiment, P and chlorophyll content in AMF+ lettuce plants were higher than in AMF- plants, indicating that the photosynthetic rate was improved with AMF inoculation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.363-369
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• 2015

We investigated the effect of harvesting time on the proximate compositions and biological activities of Lactuca indica L. Seonhyang and wild species. The highest moisture content (91%) was obtained from Seonhyang harvested in June. The wild species harvested in August showed the highest crude protein (4.8%) and crude fiber contents (2.7%). Potassium contents were 626~684 mg/100 g, and no significant difference in harvesting time was observed between Seonhyang and wild species. Calcium and phosphate contents of Seonhyang leaves harvested in August were highest (350 mg/100 g and 123 mg/100 g, respectively). The highest total polyphenol and total flavonoid contents were observed for wild species harvested in June (60 mg/g and 126 mg/g, respectively). Ethanol extracts of Seonhyang and wild species leaves harvested in June showed the highest DPPH radical scavenging activity (95%). ${\alpha}$-Amylase inhibitory activity was highest (94.8%) in water extract of Seonhyang leaves harvested in July. Nitric oxide production inhibitory activity was $14.3{\mu}M$ in ethanol extracts of Seonhyang and $16.8{\mu}M$ in ethanol extracts of wild species harvested in June. Calcium content and ${\alpha}$-amylase inhibitory activity of Seonhyang leaves were greater than those of wild species leaves. These results suggest that Seonhyang leaf can be used to develop processed foods.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.7-12
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• 2000

Explants of lettuce (Lactuca sativa L.) were co-cultivated with Agrobacterium tumifacience GV 3101 strain containing nptII gene and cold regulated gene (BN115) from Brassica napus for transformation. Multiple shoots were obtained from the explants in the selection medium (MS basal medium supplemented with 100 mg/L kanamycin, 500 mg/L carbenicillin, 0.1 mg/L NAA, 0.5 mg/L kinetin) after 3 to 4 weeks of co-culture. The putative transgenic shoots were transferred to rooting medium (1/2 MS basal medium supplemented with 100 mg/L kanamycin and 250 mg/L carbenicillin). The selected shoots were tested with PCR analysis using nptll, BN115 primers whether cold-regulated gene was introduced to genome of the plants. The vir G primers were particularly used to check contamination of Agrobacterium during PCR analysis. The nptII and BN115 primers produced the specific PCR bands in the putative transgenic lines but the vir G primers did not. These results confirmed that the PCR products were not the result of contamination with Agrobacterium. Additionally the Southern analysis of the PCR products and RT-PCR analysis proved that the cold-regulated gene was successfully integrated and transcribed in the putative transgenic lettuce plants.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.138-151
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• 2013

This study was carried out to investigate the distribution and habitat types of prickly lettuce, Lactuca scariola of Europe origin for supplying the basic data of management plan. It showed fairly nation-wide distribution although excessive growth was rather limited in the wild. Its habitat types were divided into four types like open fields, roadsides, seashores and riversides. Species diversity examined by species rank-dominance curve tended to increase over riverside > seashores > open fields > roadsides. As a result of analyzing life form, therophytes were more than 50%, means that the habitats of L. scariola were disturbed by human activities etc. Urbanization Index was analyzed 9.1% in roadsides, 7.4% in seashores, 5.8% in open fields and riversides. It has high spread potential with a large number of wind-flying seed per plant. It was evaluated that prickly lettuce was mainly spread along the newly constructed road, expressway and invaded the original ecosystem in the cultivated land as weeds. But it has played a role as a pioneer species in open fields. It is recommended to remove where it has considerable impact on the native plant species of conservation value.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.63-68
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• 2002

The possibility for mass production of phytol, inhibitory diterpene against ACAT (Acyl-CoA: Cholesterol acyltransferase) was investigated by using callus culture of lettuce. The callus were induced from lettuce cotyledon explants on MS medium containing 0.5 mg.L$^{-1}$ NAA after 4 week's culture. Adventitious roots were formed from the explants on MS medium containing 0.5 mg.L$^{-1}$ IBA or 1.0 mg.L$^{-1}$ NAA. Adventitious shoots and roots were emerged from the callus when the callus was transferred to MS medium containing auxin alone, or with cytokinin. The plant growth regulators and their concentrations for the organogenesis were 1.0 mg.L$^{-1}$ NAA, 0.1 mg.L$^{-1}$ BA, 0.5 mg.L$^{-1}$ NAA with 0.1 mg.L$^{-1}$ kinetin, or 0.5 g.L$^{-1}$ 2.4-D with 1.0 mg.L$^{-1}$ kinetin. Analyses of chlorophyll contents showed that chlorophyll contents were higher in morphogenic calli than in non-morphogenic calli. However, the chemical analyses of gas chromatography indicated that phytol contents were not proportionate to the chlorophyll contents of callus. The content of phytol was higher in callus than in lettuce cotyledon.ledon.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.239-246
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• 2022

Lactuca scariola L. is one of ecosystem-disturbance plants that grow everywhere such as roadsides, grasslands, railroads, banks, and fields. L. scariola usually occurs in autumn. It overwinters in rosette form. It flowers and produces seeds in early summer of the next year. Seeds of L. scariola can germinate immediately without dormancy when the temperature is over 20℃. Due to endogenous bacteria in seeds of L. scariola, it has a strong drought tolerance. Thus, it can grow well on roadsides. L. scariola should be controlled as it can result in 60-80% of soybean yield loss at densities above 50 plants m^-2. It is advisable to remove L. scariola as it competes with native plants by acting as a pioneer to other ecosystem-disturbance plants. Among various control methods, chemical control is the most effective method that is widely used. Soil treatment with herbicides such as oxyfluorfen EC and pendimethalin EC can inhibit the development of L. scariola. Foliar treatment herbicides glyphosate and glufosinateammonium are widely used. L. scariola is resistant to 2,4-D, dicamba, and MCPA among foliar treatment herbicides. Thus, it is recommended to apply herbicides with different modes of action.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.05a
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• pp.136-138
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• 2005

• Korean Journal of Microbiology
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• v.13 no.4
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• pp.143-156
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• 1975

A rotting bacterium was isolated from decayed root of ginseng (Panax ginseng Meyer), cultured purely, and its pathogenicity was confirmed by reinoculation test. The strain causing ginseng root rot was identified as Pseudomonas fluoresens biotype II. The strain was somewhat different from P.marginalis and P.talaasii, considering the number of flagella, pathotype and ability of indole production. The strain did not exhibit pathogenicity to other plants tested, such as red kidney bean(Phasolus vulgaris L.), soy bean (Glycine max Merr.), cucumber (Cucumis sativus L.) lettuce (Lactuca sativa L.) and cowpea bean (Vigna sinensis Savi.).

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.10a
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• pp.117-117
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• 2003

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.214-215
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• 2005