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        검색결과 807

        681.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Field experiments were conducted to investigate persistence of Chinese milk vetch(CMV) seed under naturally reseeded CMV-rice cropping systems during the period of 2007~2009. Persistence of the CMV seeds were evaluated in the naturally reseeded CMV-rice field on different tillage methods and soil depths based on the seed number recovered and the seed longevity in soil. Field observation in the naturally reseeded CMV rice field showed that as many as 917~2,185 CMV seeds m-2 were found from 0~15cm soil depth in the rotary tillage and 250~10,105 CMV seeds in minimum tillage rice cultivation in autumn. The recovered seed germinated 25~33%, 23~43% but still had high percentage of hard seed having 64~72% and 51~77%. Field experiment showed that the CMV seedling still emerged even after 2 years of continuous destructive killing of emerged CMV plant by rotary tillage in naturally reseeded CMV-rice field, indicating that CMV seeds persistent at least two years in rice field.
        682.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Experiments were conducted to investigated the change of primary dormancy and viability of Chinese milk vetch(CMV) seed buried in soil both as seed and pod with seeds under CMV-rice cropping system during the period of 2007~2009. The freshly harvested CMV seed alone and pods with seeds were buried in rice field at 0, 5 and 10cm depths and determined change of seed dormancy and viability at one to three month intervals for 10 months. The CMV seed had high dormancy of 95%, showing only 4~5% germination at the beginning in June but the seed dormancy was gradually broken at rice harvest time in autumn, showing 25 to 35% for seed and 55 to 61% for pod with seeds. The viability loss was faster in the seed than in the pod with seeds regardless of depths of placement in the soil base on decayed seeds. Also the seed placed on the soil surface lost viability faster than the 5~10 burial depths. However, appreciable number of CMV seeds still remained at even 4 months after burial in soil. These results indicate that seed dormancy was enable CMV plant to regenerate naturally from the remained soil seed bank at rice harvest time in autumn.
        683.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        In this study, a series of laboratory experiments were carried out to investigate the weak reflection of regular and random water waves over a train of protruded permeable shore structures. A cylindrical slit type breakwater and the alternatives are employed and compared for reflecting and transmitting capabilities of incident waves including wave forces. A series of random waves were generated by using the Bretschneider-Mitsuyasu frequency and directional spectrum. Measured spectrum of irregular waves without breakwaters is verified by comparing with those of the input waves generated. Weak reflection is occurred at the breakwater center of the peak frequency. If the row of breakwaters is fixed at three layers and the relative height of breakwater is fixed at 0.6, around 45% of incident wave energy is reflected to offshore. It is also found that the transmission of directional random waves increases as the maximum frequency parameter increases. A very good agreement is observed. Reflection coefficients of permeable submerged breakwaters are less than those of impermeable breakwaters. The upside-down L shape is recommended for a small fishery harbor mooring in terms of reflecting capability and of practical application. The final design was applied to the wharf of a small beach of Seolly, near Namhae at the southeast coast of Korea.
        684.
        2009.06 KCI 등재 서비스 종료(열람 제한)
        A cDNA clone encoding a MDR-like ABC transporter protein was isolated from Brassica rapa seedlings, through rapid amplification of cDNA ends (RACE). This gene (named as Brmdr 1; GenBank accession no.: DQ296184 ) had a total length of 4222 bp with an open reading frame of 3900 bp, and encoded a predicted polypeptide of 1300 amino acids with a molecular weight of 143.1 kDa. The BrMDR1 protein shared 71.0, 62.5, 60.0 and 58.2% identity with other MDR proteins isolated from Arabidopsis thaliana (AAN28720), Coptis japonica (CjMDR), Gossypium hirsutum (GhMDR) and Triticum aestivum (TaMDR) at amino acid level, respectively. Southern blot analysis showed that Brmdr1 was a low-copy gene. Expression pattern analysis revealed that Brmdr1 constitutively expressed in the root, stem petals and stamens, but with lower expression in leaves and open flowers. The domains analysis showed that BrMDR1 protein possessed two transmembrane domains (TMDs) and two nucleotide binding domains (NBDs) arranging in "TMD1-NBD1-TMD2-NBD2" direction, which is consistent with other MDR transporters. Within NBDs three characteristic motifs common to all ABC transporters, "Walker A", "Walker B" and C motif, were found. These results indicate that BrMDR1 is a MDR-like ABC transporter protein that may be involved in the transport and accumulation of secondary metabolites.
        685.
        2009.06 KCI 등재 서비스 종료(열람 제한)
        Morphological characteristics of leaves, trichomes and acorns were investigated in 6-year-old artificial hybrids of Q. aliena × Q. mongolica var. crispula and Q. serrata × Q. mongolica var. crispula. Leaf shapes of Q. aliena × Q. mongolica var. crispula F1 were obovate and resembled to that of Q. aliena. But several characters including the size of leaf and petiole and the shape of leaf base resembled to those of Q. mongolica var. crispula. In F1 hybrids, small stellate hairs distributed sparsely on the abaxial surface and their lay length was intermediate between both parents. There were no big differences on characters of nuts and cupules between both parents and F1 hybrids. Leaf shapes of Q. serrata × Q. mongolica var. crispula F1 were obovate-elliptic, and the leaf shape and leaf base and the length of petiole resembled to those of Q. mongolica var. crispula, but leaf size and serration resembled to those of Q. serrata. The number of serration in a leaf was intermediate between both parents. Small stellate hairs distributed sparsely and large single hairs were mixed on the reverse side of leaves. there were no big differences on the number and size of stellate hairs between F1 hybrid and Q. serrata. It is able to distinguish F1 hybrids from both parents by the size leaf size and shapes, leaf base and serration, petiole length and trichome type in the leaf.