• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.75-80
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• 1998

Disbudded epicotyl cuttings from light-grown 6-day-old seedings of Vigna angularis Owhi et Ohashi were preincubated in $2\;\times\;10^{-4}M$ IAA solution for 48 hr to promote adventitious root formation in upright or inverted direction and then incubated in upright direction for 96 hr. Adventitious root formation occurred only at the morphological base of the cuttings which were preincubated in upright direction, while at the both ends in inverted direction. IAA treatment enhanced the adventitious root formation in all cuttings regardless of their orientation during preincubation. To elucidate localized root development, the activity of enzymes involved in root initiation and development was measured 24 hr, 48 hr, and 148 hr after epicotyl incubation. IAA oxidase, peroxidase and catalase were assayed in the apical, middle and basal segment of the epicotyls, and their fresh weight and length were measured. Elongation occurred the most in the upper segment of the epicotyl while fresh weight gain was the most in the basal segment. At root initiation phase, 24 hr after incubation IAA peroxidase and catalase activities appeared high at rooting zone while IAA oxidase activity was low at both ends, IAA oxidase and peroxidase activities declined at the rooting zone during the adventitious root formation at 48 ht. Inversion of cuttings during preincubation caused a chrange of enzyme activities along their epicotyl cuttings. Only peroxidase activity showed a high correlation with root initiation. Therefore, the biochemical change is highly correlated with change in IAA level in the rooting zone of the epicotyl, resulting in root formation in unusual rooting zone of epicotyl.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.154-158
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• 2019

BACKGROUND: 'Shiranuhi' mandarin is a major cultivar among all late ripening type of citrus, and is widely cultivated in Korea. However, many farmers have reported scion root problems in their orchard resulting in reduced flowering and fruiting. It is necessary that the physiology of scion-rooted 'Shiranuhi' mandarin trees is further understood. METHODS AND RESULTS: This experiment was conducted to understand the growth response and physiology of scion-rooted 'Shiranuhi' mandarin hybrids. In our study, 'Shiranuhi' mandarin trees were divided into two groups: trees without scion roots (control) and trees with scion roots. The experiment was conducted in Seogwipo of Jeju, with ten replicates for each group. Growth of trees with scion roots was more vigorous and the trees were taller than the controls. Tree height and trunk diameter of scion-rooted trees were significantly higher than those of control trees. Exposed length of rootstocks of scion-rooted trees was significantly lower (by about 2 cm) than that of control trees (8.6 cm). In terms of root nutrition, carbon contents of scion-rooted trees was significantly lower than that of control trees, but nitrogen and potassium concentrations in scion roots were significantly higher than those in control roots. CONCLUSION: Based on the results, we infer that growth of scion-rooted trees was very vigorous and the content of nitrogen in these roots was higher than that in the control tree roots. Thus, the carbon/nitrogen ratio of scion roots was significantly lower than that of the control roots.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.100-105
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• 2016

In this study we investigated the suitability of horticultural main organic root substrate materials (peatmoss, coir) for the development proper root substrate for working with bulb onion transplanter. We investigated seedling sprout ratio, growth and characteristics (bulk density, root substrate cohesion) those are suitable for mechanical transplanting by mixing with inorganic materials(red clay etc.). Although both seedling growth and root substrate bulk density were similar in peatmoss and coir based root substrates, we found that peatmoss mixing had higher root substrate cohesion compared to coir mixing. We assume that higher cohesion properties of peatmoss based root substrate will give more weight of root part during mechanical transplanting of young onion seedlings in the field. Because of this, we suggest that peatmoss is the appropriate ingredient for developing root substrates for working with bulb onion transplanter.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.614-622
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• 1995

Root caries is very frequently developed on exposed root surface after periodontal surgical treatment. In order to determine the anti-caries effect of Nd : YAG laser irradiation on periodontally exposed root surface, 40 mandibular molar teeth that had been extracted due to excessive periodontal destruction were used as the experimental teeth. All teeth were treated by the same procedure as conventional periodontal root treatment, ie thorough scaling, root planing and root conditioning with tetracycline HCl(100mg/ml, 5min.). Within middle one third of root, mesial half surface(20) or distal half surface(20) was randomly irradiated at various power of 1.0W, 2.0W, 3.0W and 4.0W for 60 seconds by non-contact(5mm) delivery of a pulsed Nd : YAG laser(EN.EL.EN060, Italy). The microhardness was measured by Vikers microhardness tester(Wilson, USA) at 2mm/second of jog speed under 100gm load. The difference of microhardness between irradiated side and non-irradiated side was statistically analyzed ANOVA and Duncan's method. Following results were obtained ; 1. The microhardness(Knoop hardness number) was significantly higher in laser irradiated surface than non-irradiated surface(p<0.05). 2. There was no significant difference in microhardness between experimental groups classified by different laser power(p>0.1). The results suggest that Nd : YAG laser irradiation on exposed root suface after periodontal therapy may inhibit the root caries development by enhancing surface microhardness.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.159-163
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• 2001

Influence of soil temperature [accumulated degree-day for the base temperature $5^{\circ}$($\textrm{DD}_5$)] on the development of Meloidogyne arenaria were studied in a winter grown oriental melon greenhouse in Seongju, Korea. Egg masses were first observed on roots at the accumulation of 565 $\textrm{DD}_5$(40 days after transplanting), suggesting that the nematode has completed the first generation in 40 days. Second-stage juveniles (J2) densities were lowest at 863 $\textrm{DD}_5$ in April, first increased at 1,334 $\textrm{DD}_5$ in May, peaked at 2,951 $\textrm{DD}_5$ in July, and decliner thereafter. Development of egg masses and J2 density in soil revealed that M. arenaria could develop in 7-8 generations in a year in the greenhouse. Degree-day monitoring, therefore, could aid to predict nematode development in soil and can be valuable tool a to develop root-knot nematode control strategies.

• Research in Plant Disease
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• v.16 no.1
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• pp.10-20
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• 2010

Root-knot nematodes cause billions of dollars in crop losses annually have a broad range of host over 2,000 species of plants. These nematodes are known as obligate, sedentary endo-parasites in a plant host to feed upon to complete their life cycle. To prevent the plant parasitic nematode, methyl bromide was widely applied as a soil fumigant. Other strategies to prevent or control nematodes involve RNAi-mediated suppression, R gene transformation, natural products or chemical treatments, the expression of peptide or proteins in susceptible plants, and others. Over the last decade, the entry in GenBank for Meloidogyne reveals 73,340 ESTs and recently two complete Meloidogyne spp. genomes sequences have simultaneously been presented by two groups. Recent works have demonstrated the effect of RNAi suppression to nematode target genes. These results will provide novel members of genes as a foundation for studies focused on understanding the function of M. incognita nematode genes as well as for the development of novel target genes for parasite control. Thus the successful development of biotechnology-derived plants with nematode resistance will result in large yield benefits for producers as well as environmental benefits and will accelerate the research related to pathogensresistant crops.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.142-146
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• 2002

The effect of potassium phosphonate ($KH_2PO_3 or $K_2 HPO_3$) on the control of Phytophthora root rot of lettuce was evaluated in a liquid hydroponic culture. Phosphonate 100 ppm strongly inhibited mycelial growth of Phytophthora species in vitro but did not affect normal growth of lettuce in a greenhouse test. Application of the chemical before infection showed over 94% control value, while it was less than 35% when applied after infection. In a field trial, phosphonate 100 ppm, which was directly supplemented into the nutrient solution, satisfactorily controlled the disease as it did not develop until 28 days after transplanting and remained at less than 2% infection rate at the end of cultivation. Meanwhile, in the control plot, the disease initiated at 7 days after transplanting and developed rapidly reaching over 70% infection rate at 28 days. Population density of the causal pathogen, R drechsleri, in a heavily infested farm was 22.0-25.0 cfu/100 ml of nutrient solution. However, it decreased to 1.3-2.0 cfu/100 ml at 7 days after treatment with phosphonate 200 ppm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.13-17
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• 2007

The green roof industry have been developed with Europe, North America, Japan. At the same time, being recognized the important of green roofs in domestic industry and we just start to develop the relative technology as analyzing the future direction of advanced technology. Recently, local self-government including Seoul support the system for green roof which provide 50% of working expenses form of Matching Fund by Seed Money. As years go by, the number of build up the green roof has gradually increased to be proved. At this result caused by management of system in government, unstructured construction system, low development of support technology. In this study as analyzing the present of technical development, supporting by law and system for the advanced waterproofing and root penetration resistance technology, we suggest the development direction of it to be compared with application advanced technology and we could strengthen the international competitiveness to be industrialized the green roof considering system, technology, human infrastructure.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.45-53
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• 1984

This experiment has been made to find out the influence of soil bulk density on growth and root development of Populus alba ${\times}$ P. glandulosa in Buyeo-kun, Chungnam. Bulk density and porosity significantly change according to slope position and soil depth and have a significant effect on tree height, DBH, biomass, and the distribution of root development. The results extracted from the experiments are as follows; 1) Bulk density in average changes from $1.17g/cm^3$ (1.05 ~ 1.40) in lower slope position to $1.43g/cm^3$ (1.36 ~ 1.60) in upper slope position, and porosity from 52.65% (55.05 ~ 45.50) in lower slope position to 41.20% (43.81 ~ 37.21) in upper slope position. 2) Bulk density increases significantly with soil depth. 3) Tree height, DBH, and total biomass decrease with bulk density. 4) Foliage, branch, bolewood, bolebark, and root also significantly have a negative correlation with hulk density. 5) Populus alba ${\times}$ P. glandulosa has a shallow root system chiefly distributing only in AI horizon, and critical bulk density is $1.43g/cm^3$. Therefore, slope position, hulk density, and porosity are considered to influence on the growth, biomass, and root development of Populus alba ${\times}$ P. glandulosa.

• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.1-6
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• 2001

This research was carried out to establish the large quantity propagation system for Kalopanax pictus using root cutting. The results are as follows. As there was no significant difference in the promotion of adventitious shoot development from the root cuttings of Kalopanax pictus among kinds (IBA, NAA and Kinetin) and concentrations (0 to 2000 mg/L) of growth regulators, no application is recommended, which showed more than 90% of shoot development. Horizontal and vertical placement of rooting showed more than 93% of shoot occurrence, but the latter showed more desirable growth traits in the number of shoot development, number of leaf, petiole length, and leaf length and leaf width Polarity was observed and thus normal vertical placement of root cutting is preferred. However, root cuttings placed upside down showed the shoot development at the distal end, which indicates further sophisticated test is necessary to investigate this phenomenon.