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        검색결과 7

        2.
        2016.04 구독 인증기관·개인회원 무료
        Although expression of foreign genes in a crop species has been target techniques for powerful protection against insect pests, classical breeding programs using varietal resistance of a crop are still being processed. It is, however, frequently difficult to find key products expressed from resistance-related genes in the variety, and those action mechanism. Here, an unterminated story about seed of a mungbean (Vigna radiata) variety with high resistance against the adzuki bean weevil and the bean bug is introduced. The two insects cannot survive on seeds of the variety, although they well develop on susceptible ones. Molecular markers linked to the resistance were selected through BAC library screening and near isogenic lines, and finally a bruchid resistance gene was suggested after map-based cloning approaches. Starvation and chemicals were suggested for a resistant mechanism and a related factor through feeding and behavior experiments, respectively. The seed flour was extracted with organic solvents, and isolated into several fractions on chromatography. Several peaks on HPLC in a fraction were related with the high mortality of the bean bug. A partial structure in an isolated chemical was observed before full identification.
        3.
        2016.04 구독 인증기관·개인회원 무료
        Some Japonica rice plant varieties show the resistance to the whitebacked planthopper (S. furcifera) and the varieties produce ovicidal compound, benzyl benzoate, to kill their eggs lying in the rice plant. We have tried to elucidate the mechanism for inducing the production of the benzyl benzoate by the Japonica rice varieties. The active 80% MeOH/H2O extract was chromatographed on ODS open column and separated into 6 fractions; 100% H2O, 20% MeOH/H2O, 60% MeOH/H2O, 80% MeOH/H2O, 100% MeOH, 100% EtOH. Of these 6fractions, 100% MeOH and 100% EtOH fractions evidently induced benzyl benzoate at 43.95μg/g of fresh rice plant(frp) and 31.04μg/gfrp, respectively. The active compounds were submitted to analyses by using NMR and GC- and LC-MS inorder to elucidate the structure. We find elicitors to induce with S. furcifera. The elicitors are in the female of S. furcifera and the structures of elicitors are species of phospholipid and glycerol.
        4.
        2014.04 구독 인증기관·개인회원 무료
        We elucidate the mechanism for inducing the production of ovicidal benzyl benzoate by Japonica rice varieties to kill eggs of the whitebacked planthopper, Sogatellafurcifera(Horváth), lying in the rice plant. Even when subjected to physical damage by a needle or damage with water, the rice plant produced no benzyl benzoate. However, significant benzyl benzoate was produced when the plant was damaged with a methanol extract or homogenate of S.furcifera. The extract of the male did not induce the production of benzyl benzoate, but that of the female did. We concluded from these results that benzyl benzoate was induced by some elicitor(s) in the female of S.furcifera.
        5.
        2011.05 구독 인증기관·개인회원 무료
        From the methanol crude extracts of the tree of heaven (Ailanthus altissima) leaves, the antifeedant substance was isolated and bioassayed with different concentrations against diamondback moth (Plutella xylostella) larvae. The antifeeding activity was evaluated by measuring the feeding area during 24 hr after inoculation. Methanol extracts showing antifeeding activity at 5000 ppm was subsequently fractionated into hexane, chloroform, ethyl acetate and water layer. Third larvae of diamondback moth was tested to each fraction layer. Chloroform layer shows the highest antifeeding activity and the layer was purified by silica gel open column chromatography. The C22 and C23 fractions showed higher antifeeding ratio with 96 and 86%, respectively, and then these two fractions were re-isolated by ODS open column chromatography. As a result, both fractions in methanol 40% (v/v) showed antifeeding ratio over 90%. The C221 fraction showed insecticidal activity in all fraction, however, C231 fraction was showed the antifeeding activity only in C2311 fraction. The C2311 fraction judging to have antifeeding activity was re-isolated and purified by HPLC and recycling, and finally obtained the bioactive substances (C23111) with antifeeding ratio with 88%. The structure of bioactive materials isolated was confirmed by LC-mass and 1H-NMR(500 MHz), 13C-NMR(100 MHz).
        6.
        2009.10 구독 인증기관·개인회원 무료
        Using thirty-one essential oils with different manufactured T-tube olfactometers, attraction and repellent efficacy were proved against ggot-mae-mi, Lycorma delicatula. Among tested essential oils, spearmint was selected to have attraction efficacy (94.1%; P<0.001). Spearmint was also showed attraction efficacy in 10 and 2.5 ul, but did not showed in 1 ul. GC analyzed chemical constituents of spearmint were tested with different concentations (10, 5, 2.5, 1 ul). Carvone were showed activity in 10 and 5 ul, but limonene did not showed the activity. When mixing two compounds were showed activity in 10, 5, 2.5 ul as 78.8, 73.5, and 69.7%, respectively. Lavender was selected to have repellent efficacy (86.7%; P<0.001). Lavender was also showed repellency in 10 and 2.5 ul, but did not showed in 1ul. GC analyzed chemical constituents of lavender were tested with different concentrations, results have the activity linalool and terpinen-4-ol in 10 and 5 ul, but linalyl acetate and caryophyllene oxide did not have the activity. Spearmint and lavender showing attraction and repellency, respectively, were keep in lure during 24 hr for penetration with different concentration(30, 20, 10 ul), and attached to the center of Fly catcher, fly sticky trap. The trap was set in the field that founded frequently the L. delicatula. The number of L. delicatula caught in the traps were counted after 5, 10, and 15 days. In attraction efficacy of 20 ul concentration wㄷre high attracted the insect(P<0.001). 30 ul concentration were also have the high attraction (P<0.01). We are now tested the control efficacy in grapevine orchard using these materials.
        7.
        2009.05 구독 인증기관 무료, 개인회원 유료
        Swallowtail butterfly’s (Papilionidae) family is a large group including at least 550 species in the world, one of the most evolved butterfly families, and selects many special plants as a host plant. Many scientists have studied on the mechanism for host selection by swallowtail butterflies and many results including attractant, ovipositional stimulant, and feeding stimulant in each host plant have been reported. However, most of the reports are related to Papilinonini and Troidini genus and not to Graphiini genus. The reason why there are few reports about this genus is based on their nature. That is, this genus butterflies, especially common bluebottle, Graphium sarpedon, are very nerves and rearing for successive generations is difficult in the laboratory, emergence-adult never laid their eggs on the host plant and so on. We, therefore, have tried to isolation and identification of attractant, feeding stimulant, and ovipositional stimulant in the camphor tree to the common bluebottle, G. sarpedon.
        3,000원