Variations in antioxidant capacity of leaves and characteristics of seed germination among five Hibiscus hamabo populations in Korea were evaluated. While the leaves of H. hamabo from Shincheon contained highest Na concentration, those from Hado and Ohzo does lowest. MDA content and SOD activity didn't show significant difference among populations, but total protein and anthocyanin content were significantly different among five populations. The filled seed rates of five populations were ranged from 92.0 to 98.7%, and the moisture contents of seeds from Shinyang and Soando were lower than that of R. syriacus (5.18%). The fresh weights of H. hamabo from Hado and Ohzo were the highest and those of seeds from Shinyang and Soando were the lowest. Significant variations among H. hamabo populations were detected for all seed germination characters: percentage of germination, average germination time and germination rate and uniformity. SOD activities of seeds from Onpyoung and Soando were the highest of five populations, and total protein concentrations of seeds in Ohzo and Shinyang populations were higher than those of other populations. H. hamabo is considered exposed to salt stress and all characteristics of seed germinations were inferior to other species.
The growth and yield performance of 19 new com hybrids were evaluated. Results showed that all hybrids had a superior growth performance in the drained-paddy than in the upland field except for daeyul × cheongdo and hyoryeong × cheongdo in plant height, cheongdoyeop × wx-3 in tassel1ength, and cheongdo (black) × wx-3 in number of tassel branch. The same hybrids, except cheongdoyeop × wx-3, obtained lower ear quality in drained-paddy field compared to upland in terms of ear weight, and ear and grain setting length. The highest yield in the drained-paddy and upland fields was obtained in the hybrids ks5wx × ks6wx × cheongdo (1,633.3kg · 10a-1) and daeyul × wx-3 (1,516.7kg · 10a-1), respectively. Highest yield among the wx-3 crosses was obtained in daeyul which was 1,583.3kg · 10a-1 and 1,516.7kg · 10a-1 in drained-paddy and upland field, respectively. For the crosses of wx-8, highest yields were recorded in the cultivar bugye50 (1,466.7kg · 10a-1) and seokgu12 (1,384.6kg · 10a-1) for drained-paddy and upland field, respectively. In the case of cheongdo, highest yields were obtained in ks5wx × ks6wx (1,633.3kg · 10a-1) and seokgu14 (1,111.1kg · 10a-1) for drained-paddy and upland field, respectively. Result also showed that the drained-paddy soil had better physicochemical properties than the upland. The relatively high performance in terms of growth parameters and yield of com hybrids planted in the drained-paddy field is in agreement with the higher organic matter and micro-element content of drained-paddy field.
This experiments were carried out to find out the effects of different explant materials, kinds and concentration of plant growth regulators, and total nitrogen and sucrose contents on the in vitro regeneration of Abeliophyllum distichum Nakai. The effects of growth regulators on regeneration from 3 explant sources (leaf, internode and node) were more or less same. Leaf explants produced only callus with 2ip (Isopentenyladenine) and NAA (Naphthaleneacetic acid) treatment and other regulators had no effects. Test with internode explants yielded about same results but callus was obtained with 2,4-D (2,4-Dichlorophenoxyacetic acid). Node explants resulted in shoot regeneration by all regulator treatment except NAA and 2,4-D, but control also showed similar results. Callus formation from internode and node explants was vigorous by 2ip, zeatin, and 2,4-D treatments and high NAA concentration resulted in higher callus formation. In this experiment, various mixed treatment of growth regulators were also employed, using node as explant material. Shoot regeneration was obtained with BA (Benzyl adenine) + NAA treatments but the results were comparable with control. Generally shoot and root regeneration was poor with all combined treatment except 2ip + NAA and 2,4-D + NAA. However, callus was formed readily with all treatments. In this experiment, combined treatments of regulators were applied on the callus derived from singular regulator treatment. The results showed no shoot and root regeneration with any combination of 2,4-D, IAA (Indoleacetic acid) and NAA, but soft milky white callus was formed in all the treatments. No shoot and root regeneration was observed with any combination of 2iP, NAA and IAA, but somewhat hard, light green callus was formed in all the treatments. Callus formation decreased with high kinetin concentration in case of kinetin + NAA treatment. The experiments with total nitrogen content of media showed that low concentrations of 15 and 30mM were effective for the shoot and root regeneration. Sucrose experiment demonstrated shoot regeneration with 1~4% concentration, and root and callus formation with 2~4%. No root and callus formation was observed with 0 and 1% sucrose.
This study was conducted to find out some important agronomic characteristics and qualities in response to different transplanting dates in Alisma plantago at southern parts of Korea. Yield components such as number of floral axis per plant, plant height and number of leaves were highest at the transplanting date of Aug. 15 and Aug. 25. Plants sown at Aug. 15 and Aug. 25 also showed highest yield. Considering from our results, optimum transplanting date were semed to be transplanting date of Aug. 15 and Aug. 25.
Phytotoxicity, antioxidant activity, and cytotoxicity of the aqueous or methanol extracts from the young sprouts of the six Compositae medicinal plants were determined. Aqueous leachates at 40g dry tissue L-1 (g L-1) Cirsium japonicum and Aster yomena showed the highest inhibitory effect on alfalfa (Medicago sativa L.). Total phenolic content showed the highest amount in methanol extracts from Ixeris dentata, and followed by A. yomena, and Cephalonoplos segetum. Methanol extracts of C. segetum and I. dentata at 25μg mL-1 exhibited the highest DPPH radical scavenging activity by 87.2, and 52.8%, respectively. By means of HPLC analysis, MeOH extracts of C. segetum had the highest amount of antioxidant chlorogenic acid. Based on MTT assay, the methanol extracts from Y. sonchifolia (IC50 = 65.7μg mL-1) showed the highest cytotoxicity against Calu-6. These results suggest that plant extracts had a dose-dependent biological potentials including phytotoxicity, antioxidant activity, and anticancer activity, and that their activities exhibited differently depending on plant species.
We have cloned an LTP gene (PoLTP1) from poplar (Populus alba × P. tremula var. glandulosa) suspension cells and examined changes in its expression levels in response to various stresses and ABA treatment. The full-length PoLTP1 cDNA clone encodes a polypeptide of 116 amino acids with typical characteristics of LTPs, notably a conserved arrangement of cysteine residues. Southern blot analysis indicate that two or three copies of the PoLTP1 are present in the genome of the investigated hybrid poplar. In addition, northern analysis of samples from soil-grown plants indicate that PoLTP1 is tissue-specifically expressed in the leaves and flowers. The gene is significantly up-regulated by treatment with mannitol, NaCl and ABA, but not by either cold or wounding. These results indicate that PoLTP1 is involved in osmotic stress responses in poplar plants and suspension cells.
Gene-expression analysis is increasingly important in biological research, with real-time reverse PCR (RTPCR) becoming the method of choice for high-throughput and accurate expression profiling of selected genes. However, this technique requires important preliminary work for standardizing and optimizing the many parameters involved in the analysis. Plant stress studies are more and more based on gene expression. The analysis of gene expression requires sensitive and reproducible measurements for specific mRNA sequence. Several genes are regulated in response to abitoic stresses, such as salinity, and their gene products function in stress response and tolerance. The design of the primers and TaqMan probes for real-time PCR assays were carried out using the Primer ExpressTM software 3.0. The PCR efficiency was estimated through the linear regression of the dilution curve. To understand the expression pattern of various genes under salt stressed condition, we have developed a unique public resource of 9 stress-related genes in poplar. In this study, real-time RT-PCR was used to quantify the transcript level of 10 genes (9 stress-related genes and 1 house keeping gene) that could play a role in adaptation of Populus davidiana. Real-time RT-PCR analyses exhibited different expression ratios of related genes. The data obtained showed that determination of mRNA levels could constitute a new approach to study the stress response of P. davidiana after adaptation during growth in salinity condition.
The Purpose of this study was to offer the raw data for drawing up the conservation plan by analysing natural vegetation in Midongsan, Chungcheongbuk-do, Korea. The period of survey was from July to October, 2004 and the size of plot was 100m2. In the results of analyzing the physical environments, the range of altitude was 303~550m and soil pH was 5.4~6.8. The angle of slope was 3~57% and topographical factor was composed of ridgeline. In the results of analyzing a importance percentage, the dominant species in tree layer, Pinus rigida, P. densiflora, Quercus mongolica, Q. variabilis and Q. acutissima, P. rigida, Q. mongolica, Q. acutissima, Platycarya strobilacea and Q. variabilis in subtree layer, Rhododendron mucronulatum, Symplocos chinensis for pilosa, Lindera obtusiloba, L. erythrocarpa, Rhus trichocarpa and Weigela subsessilis in shrub layer. In the results of species diversity index, species diversity (H') was from 1.2401 to 2.5540, maximum species diversity (H'max), from 1.9459 to 2.8904, evenness (J'), from 0.5644 to 0.8836, dominance (D), from 0.1164 to 0.4356.
Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.
We described and illustrated a rare species in Korea, Hypoxis aurea Lour. (Hypoxidaceae) which was rediscovered about 70 years after its first collection from Jeju island in Korea. The members of the family Hypoxidaceae R. Br. are distinguished from the plants of Amaryllidaceae J. St-Hill. by having grass-like leaves, an invisible stem which is modified into a corm or a rhizome, trimerous, and radially symmetric flowers with an inferior ovary developing into a capsule on scapes. Hypoxis aurea Lour. is readily distinguishable from Curculigo orchinoides Gsertn. in Japan by beakless ovary and capsular fruit. The number of somatic chromosome is 2n=54.
The aquatic fern Azolla spp. is of value as a bio-fertilizer for wetland paddy. It is popular and cultivated widely in other countries like China, Vietnam, and the Philippines, but has yet to be taken up in Korea, in a big way. It fixes nitrogen as high as 3-5kg N per day, because it contains nitrogen fixing blue-green algae, Anabaena azollae. Azolla's ability to create a light-proof mat that suppresses other weeds has been used for centuries in rice production. Azolla spp. has also the capacity to take up the heavy metals such as Mercury and Chromium (75~100%) and may be used as a bioaccumulator in the phytoremediation. Azolla meal also can be used as an unconventional feed resource has a potential as a feedstuff for livestock.