• Journal of Life Science
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• v.20 no.5
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• pp.750-759
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• 2010

The bioactive materials (phenolic compounds, flavonoids, minerals, decursin and decursinol angelate) and biological activities (DPPH [$\alpha,\alpha$'-diphenyl-$\beta$-picrylhydrazyl] free radical scavenging capability, reducing power, and tyrosinase activity) in the extracts of leaf, stem mixture (AGLS), and root (AGR) from Angelica gigas Nakai were examined by using water, hot water and ethanol solvent. The highest extract yield (21.89%) was found in the water extract of AGR. The highest concentrations of phenolic compounds and flavonoids in the ethanol extracts of AGLS and AGR were 14.99% and 14.79%. Major minerals of AGLS and AGR were K, Mg, Fe, Na and Ca. Decursin and decursinol angelate were the major ingredients of Angelica gigas, detected at 18.71 and 18.89 min of retention time by HPLC analysis, respectively. The highest concentrations of decursin and decursinol angelate in the Angelica gigas ethanol extract were found in root ($41.7\;{\mu}g/g$) and leaf ($34.04\;{\mu}g/g$). The highest free radical scavenging activity was found in the hot water extracts of AGLS and AGR, and its activity was stronger in all extracts of AGLS than AGR. The highest reducing power was found in the ethanol extracts of AGLS and AGR and this was dependent on the sample concentration. The hot water extracts of AGLS and AGR revealed the highest inhibition activity on tyrosinase. Overall, these results may provide the basic data needed to understand the biological activities of bioactive materials derived from Angelica gigas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.718-724
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• 1996

Two soybean cultivars, ‘Lee’ and ‘Peking’, were used to evaluate the competition and interaction of rhizobium strains PRC205 (R. fredii, fast-grower) and USDA110 (B. japonicum, slow-grower). Strains were inoculated separately on the root parts of a split-root growth system. Both root sides were inoculated simultaneously with four combinations of strain treatment to evaluate the competition of strains. And to evaluate the interaction of strains one side of split-root system was inoculated a week prior to the other side. Nodule mass and dry weight of the plants were measured 3 weeks after treatments. PRC205 showed no effective nodulation and no competing ability with USDA110 on Lee cultivar, however, contrary results on Peking cultivar. Top dry weight of Lee inoculated with PRC205 was much lower than that of any other inoculation treatments, however, in Peking that with PRC205 was higher than that with USDA110. There were no differences in root dry weight among the inoculation treatments. USDA110 used as primary inoculant suppressed nodule mass of opposite side, secondary inoculant, severely in both cultivars. PRC205 showed same tendency as USDA110 in Peking, but revealed little suppression effects on USDA110 used as secondary inoculant in Lee. USDA110 used as primary inoculant in Lee and PRC205 in Peking showed much more dry weight of soybean plants than that of other treatments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.192-198
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• 2020

Root extension is the most important growth change that occurs during cultivation. We analyzed growth changes according to young seedling age, temperature, and the degree of root cutting in order to identify factors affecting rooting after transplanting. Root cutting did not affect plant height growth rate, root growth rate was increased in plants that experienced root cutting, and 14-day-old seedlings exhibited a higher growth rate than 7-day-old seedlings. Growth temperature experiments revealed that elongation was high at 25℃ and 28℃, but tended to be low at 18℃, and root elongation was high at 22-28℃ for 7-day-old seedlings and 22-25℃ for 14-day-old seedlings. Nitrogen absorption decreased in the following growth temperature order: 25, 28, 22, 18℃, and differences in nitrogen absorption under different growth temperatures tended to be lower in 7-day-old seedlings. The amount of nitrogen taken up by roots did not differ significantly between the short root treatment and the control, and 7-day-old seedlings tended to start nitrogen absorption faster than 14-day-old seedlings. Root vitality was highest in short-rooted 7-day-old seedlings with 3 cm of root remaining, and vitality also tended to be high in short-rooted 14-day-old seedlings.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.126-130
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• 1983

This study was desinged to find out the effects of soil physical properties on root development of barley. Barley fields were selected in consideration of drainage class and texture. Soil hardness were measured at the field. Soil bulk density, air ratio and root distribution were obtained from the core samples. 1. The amount of roots were increased and the root were distributed deeper layers with better drainage class and finer soil texture. 2. Soil hardness was related to soil bulk density, and the regression coefficient was increased with clay content (Clay ; $r=0.837^{**}$, Clay loam ; $r=0.678^*$, and Sandy loam ; $r=0.654^*$). 3. There was a highly negative correlation ($r=-0,846^{**}$) between bulk density of subsoils and amount of roots and the root developments were markedly reduced in soil bulk density of $1.4g/cm^3$. 4. Bulk density of subsoils was decreased with worse soil drainage and finer texture. Especially, in case of clayey soil at imperfectly or moderately drained soils, the air phase was less than 20% and the barley growth was worse. 5. Root development were related to hardness in surface, bulk density and ok phase in 10-30cm layer, and air phase in 30-50cm layer.

• Research in Plant Disease
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• v.18 no.3
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• pp.210-216
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• 2012

Clubroot of Chinese cabbage by Plasmodiophora brassicae, was found to be high virulent to the Chinese cabbage, turnips and cabbage. It this study, the endophytic bacteria Flavobacterium hercynium EPB-C313, which was isolated from tissues of Chinese cabbage, was investigated the antimicrobial activity on the inactivation of resting spores and its control effect on clubroot disease by bioassay. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivate the resting spores of P. brassicae with 90.4, 36.8, and 26.0%, respectively. The clubroot was inhibited with 100% by dipping the seedlings of Chinese cabbage in culture solutions of F. hercynium EPB-C313 before planting, however the chemmical 'fluazinam' was 91.7% in pot tests. Complex treatment were highly enhanced control efficacy with 63.7% at field of 50% diseased plants by soil incorporation with the pellet contains organic matter and F. hercynium EPB-C313, seedling drench of culture solution of F. hercynium EPB-C313 and soil drench with 10 days after planting. These results imply that the F. hercynium EPB-C313 is a very useful biological control agent of clubroot disease of Chinese cabbage.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.225-231
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• 2002

The entomopathogenic nematodes, Steinernema carpocapsae All strain (ScA), S.glaseri NC strain (SgN) and H. bacteriophora NC 1 strain (HbN), were evaluated for the effects on egg mass formation by the northern root-knot nematode, Meloidogyne hapla in pot experiment using tomato. In the first experiment, 2.5$\times$10$^{5}$ infective juveniles (Ijs) of entomopathogenic nematodes were inoculated to 100 g of the soil infected with ca. 450 Ijs of M. hapla/100 ㎤ in 150 $mell$ container. The number of egg mass was significantly decreased to 9.4-36.5 in ScA, to 5.7-24.7 in SgN and to 11.2-16.0 in HbN treatments compared with 62.5 in M.hapla alone. In the second experiment, ScA and S.carpocapsae Pocheon strain (ScP) and SgN and S.glaseri Dongrae strain (SgD) were treated to 350 g of the soil infected with 100, 200 M.hapla larvae/100 ㎤ in 450 $mell$ container The entomopathogenic nematodes were inoculated at the rate of 2,020 Ijs and 1.6$\times$105 Ijs in 350 g soil. The number of egg mass of M.hapla were significantly decreased in the entomopathogenic nematode treatments compared with M.hapla alone although no differences were observed among Steinernema species, strains, or infection concentrations. Treatments of entomopathogenic nematodes 3 days before M.hapla inoculation were more effective on reduction of egg mass formation than those of 3 days after M.hapla treatments. Growth of tomato was not affected by entomopathogenic nematode treatments.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.317-323
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• 2012

This study was performed in order to explore the growth characteristics by growing stage in the containerized seedling and the bare root seedling of Chamaecyparis obtusa Sieb. et Zucc., which is the major plantation species of Korean southland. The height growth of 1-year-old bare root seedlings was better than containerized seedlings, which grew in the containers with capacity of 31.2 mL and 300 mL. The root collar diameter growth was the best in the containerized seedlings of container with 300 mL. The 2-year-old bare root seedlings were surveyed to be better in the height and root collar diameter growth than the containerized seedlings of container with 300 mL. In the comparison of dry mass production, it was the highest in 32 mL containerized seedlings as for 1-year-old above ground and in 300 mL containerized seedlings as for below-ground and total dry mass production. In case of 2-year-old seedlings, it was indicated to be high in bare root seedling as for the part above ground and in dry mass production of the containerized seedling as for the part below ground. In the comparison on root morphological traits of seedlings such as the total root length, the root project area, the root surface area, the average diameter in root, and the root volume, all of 1 and 2-year -old containerized seedlings showed the higher growth than the bare root seedlings except the average diameter in root. Synthesizing the results of this experiment, the containerized seedlings are relatively excellent in root development compared to bare root seedlings in the process of producing seedlings of C. obtusa, thereby being judged to have grown into excellent seedlings.

• Journal of Life Science
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• v.22 no.5
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• pp.681-686
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• 2012

Light, one of the environmental stimuli, is fundamental to the growth and development of plants. Red and far-red light are sensed using the phytochrome family of plant photoreceptors. To investigate the effect of light on root growth and gravitropism, we used the Arabidopsis phytochrome mutants grown in several light conditions. The root growth of $phyA$ reared in all light conditions except white light and was stimulated compared to the WT. The stimulation of root growth was obvious in $phyA$ grown in red light. On the other hand, the root growth of $phyB$ grown in all light conditions decreased, and the lowest rate of decrease was observed in $phyAB$ grown in white and red light. The gravitropic response of $phyA$ was stimulated compared to the WT when it was grown in all light conditions except far-red light. $PhyAB$ grown in all light conditions showed the inhibition of gravitropic response. The transcript level of ACS, one of the enzymes regulating ethylene biosynthesis, increased in $phyA$ grown in white and red light, but not in $phyA$ grown in far-red light. In conclusion, these results suggested that the $P_{fr}$ form of $phyB$ regulates the root growth and gravitropism.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.454-461
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• 1999

The dynamics of root system in the fairy rings of Tricholoma matsutake was investigated in four zones divided into 'zone of decayed mycorrhizae', 'zone of mycorrhizae for fruiting', 'zone of physiologically active mycorrhizae' and 'zone of roots free from mycorrhizal infection'. The roots of Pinus densiflora in fairy rings, which occupied 70% of upper crown, comprised about 60% and 87% of total roots and alive roots, respectively. The ratio of fine-roots of P. densiflora over total roots was relatively higher than other species since that of P. densiflora was about 45% while that of the other species was about 13% on research of fine-roots. Especially, the roots of pine comprised about 70% of total root in the zone of mycorrhizae for fruiting and the zone of physiologically active mycorrhizae, which indicated that the pine roots were closely related to the fairy rings of T. matsutake. The fine roots of P. densiflora in the zone of physiologically active mycorrhizae was about 60.7%(1,087mg/100g soil) which was about twice compared to that of other zones. It allowed us to suppose that the fine roots of P. densiflora can make active growth in the zone of physiologically active mycorrhizae, and the growth was promoted by the fairy ring formation of T. matsutake. In addition, we found 3~5 times higher amount of fine roots than that of medium roots of P. densiflora in this zone, which indicated that the fairy rings of T. matsutake locate in the region of active growth of P. densiflora' roots.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.320-324
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• 2017

Development of modern agricultural machinery and accompanying agricultural development cause soil compaction and reduce growth by stressing roots. Kalanchoe pinnata was used to investigate the impact of stress on rooting and changes in plant growth and reproduction. K. pinnata forms somatic embryos capable of asexual reproduction at the edge of leaves. Impact of root pressurization of K. pinnata on somatic embryogenesis and organ differentiation according to external stress factors was investigated by using a high concentration of agar and this phenomenon was studied histologically. Agar concentration in culture media ranged from 0.5%-1.5% to induce a compression effect on roots. The stem and leaf of K. pinnata were subjected to a microtechnique process to study changes in tissue. In vivo, K. pinnata produced 2nd and 3rd plantlets at edges of leaves from lack of water and excessive lighting conditions. In in vitro culture studies, the lower the concentration of agar, the higher the population and the higher the biomass, but plantlet did not occur in leaf bends. Conversely, as concentration of agar increased, increase in the number of individuals was low. Plantlet development occurred only in agar 1.5% medium. The difference in agar concentration was a stressor in the root of K. pinnata, and thus the pattern of asexual reproduction changed from the division method in root to a plantlet generation in leaf. This suggests root pressurization may act as stress and change in the plant reproduction pattern.