• Korean Journal of Medicinal Crop Science
• /
• v.5 no.3
• /
• pp.191-195
• /
• 1997

This study was conducted to obtain the basic information on setting up selection procedure using seedling characteristics in Angelica gigas Nakai lines. Morphological characteristics of the seedlings including height, leaf and petiole length among lines tested showed difference significantly, meaning that earlier selection was possible. Bolting rate at maturity ranged from 0.6 to 74.6% and root yield did from 350 to 3,893kg/ha. Root yield was increased in the lines with below 5% bolting rate. Heritabilities of petiole length, seedling height and leaf length in seedling stage bolting rate and root yield were high, while those of leaf length, root diameter and root length were relatively low. Bolting rate at maturity was positively correlated with seedling height, leaf length, leaf width, petiole length and number of leaves. A highly significant negative correlation was showed between root yield and seedling height, leaf length and width, petiole length, number of leaves, root length or bolting rate. From the above results the selection markers were found to be height, leaf length and petiole length in seedling stage.

• Journal of Ginseng Research
• /
• v.20 no.1
• /
• pp.78-82
• /
• 1996

In order to clarify effect of transplanting angle of seedling on shape and growth of ginseng root, ginseng of seedlings were transplanted with $60^{\circ}$ and $90^{\circ}$ respectively, and the root characters of 2-, 4- and 6-year-old ginseng were investigated. The length of main root with 45$^{\circ}$was above 7 cm (standard) but that of $60^{\circ}$ and $60^{\circ}$ was below 7 cm (standard). Number of good lateral root was above 2.3 ea for $45^{\circ}$, 0~$30^{\circ}$, but below 2.3 ea per plant for 60~$90^{\circ}$ respectively. Root fresh weight with $0^{\circ}$, $30^{\circ}$, $45^{\circ}$ was heavier than that with $60^{\circ}$ and $90^{\circ}$. Root disease infection rate was highest with $0^{\circ}$. There were, no significant difference in stem length, stem diameter, leaf area, comber of palmate leaves and leaflets per plant, ratio of missing plant, root diameter in 2-, 4- and 6-year-old ginseng.

• Journal of Ginseng Research
• /
• v.19 no.3
• /
• pp.287-290
• /
• 1995

This study was conducted to elucidate the effect of physical properties of soil in nursery bed with different densities on growth of ginseng seedling. Stem length, leaf length and leaf width of ginseng seedling showed the decreasing tendency with increasing the hardness of the nursery soil. Fresh root weight per seedling and number of available seedlings were increased significantly with decrease of the soil hardness. For solid, liquid phases, bulk density and hardness of soil, negative correlations were shown in stem length, leaf length, leaf width, root weight per seeding, and number t of available seedlings. On the other hand, gas phase, air permeability and porosity of soil had positive correlations with stem length, leaf length, leaf width, root weight per seedling and number of available seedlings. Key words Yang-Jik nursery, ginseng seedling, soil physical properties.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.28 no.2
• /
• pp.471-489
• /
• 1998

For the successful endodontic treatment, root canal should be cleaned thoroughly by accurate mechanical and chemical canal preparation and sealed completely with canal filling material without damaging the periapical tissues. The accuracy of the root canal length measurement is a prerequisite for the success of the endodontic treatment, and the root canal length is often determined by the standard periapical radiographs and digital tactile sense. In this study, the accuracy and the clinical usefulness of Digora/sup (R)/, an intraoral digital imaging processor and the conventional standard radiographs were compared by measuring the length from the top of the file to the root apex. 30 single rooted premolars were invested in a uniformly sized blocks and No.25 K-file was inserted into and fixed in each canal. Each block was placed in equal distance and position to satisfy the principle of the bisecting angle and paralleling techniques and Digora/sup (R)/ system's image and standard periapical radiographs were taken. Each radiograph was examined by 3 different observers by measuring the length from top of the file to the root apex and each data was compared and analyzed. The results were as follows; 1. In the bisecting angle technique, the average difference between the Digora/sup (R)/ system and standard periapical radiograph was 0.002 mm and the standard deviation was 0.341 mm which showed no statistically significant difference between the two systems(p>0.05). Also, in the paralleling technique, the average difference between these two system was 0.007 mm and the standard deviation was 0.323 mm which showed no statistically significant difference between the two systems(p>0.05). 2. In Digora/sup (R)/ system, the average difference between the bisecting angle and paralleling technique was -0.336 mm and the standard deviation was 0.472 mm which showed a statistically significant difference between the two techniques(p<0.05). Also, in the standard periapical radiographs, the average difference between the bisecting angle and paralleling technique was 0.328 mm and the standard deviation was 0.517 mm which showed a statistically significant difference between these two techniques(p<0.05). 3. In Digora/sup (R)/ system and the standard periapical radiographs. there was a statistically significant difference between the measurement using the bisecting angle technique and the actual length(p<0.05), But there was no statistically significant difference between the measurement using the paralleling technique and the actuallength(p>0.05). In conclusion. the determination of the root canal length by using the Digora/sup (R)/ system can give us as good an image as the standard periapical radiograph and using the paralleling technique instead of the bisecting angle technique can give a measurement closer to the actual canal length. thereby contributing to a successful result. Also. considering the advantages of the digital imaging processor such as decreasing the amount of exposure to the patient. immediate use of the image. magnification of image size. control of the contrast and brightness and the ability of storing the image can give us good reason to replace the standard periapical radiographs.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.10a
• /
• pp.459-466
• /
• 2002

This study reviews the engineering properties of vegetation as one of all factors to select vegetation species for slope protection. The vegetation species mainly applied in domestic soil slope protection were inspected, and the root properties such as root pattern, root length, root weight, were analyzed. And then direct shear tests on undisturbed fine sand including roots were performed to review the effect of root reinforcement. From these analyses, it was concluded that the engineering properties of vegetation should be considered to select vegetation species for slope protection.

• The Korean Journal of Ecology
• /
• v.19 no.1
• /
• pp.36-46
• /
• 1996

Variation of Al tolerance in Pinus densiflora, P. rigida and P. thunbergii was investigated in a solution culture. Root length decreased as Al concentration increased, and decreased more in dilute culture media than in dense one. Aluminum tolerance based on relative root length was in the order of P. rigida ＞ P. densiflora ＞ P. thunbergii. Al content in tissue increased as Al concentration of the media increased, but the reverse was true for content of Ca and Mg. Al tolerance for root length showed intraspecific variation, even under the same Al concentration in the media.

• The korean journal of orthodontics
• /
• v.34 no.3 s.104
• /
• pp.241-251
• /
• 2004

Previous studies have focused on the causes of root resorption after orthodontic treatment and treatment methods to reduce this phenomenon, and have been mainly associated with developed, mature roots. As parents become increasingly interested in their children's' dentition, orthodontists are performing fixed orthodontic treatment on patients of less than 10 years and before the completion of the immature root. Thus, the author evaluated the changes of root length and root form of maxillary immature incisors after orthodontic treatment, compared with those of mature teeth, and investigated the correlation according to gender, treatment duration, and displacement of incisors. The sample consisted of an immature root group of twenty-eight persons (between 8 and 10 years old) and a mature root group of thirty-one persons (between 11 and 15 years old). The crown and root length of the maxillary four incisors were measured with a periapical radiograph, changes in root length and crown-root ratio were calculated, and root form was classified according to a scoring system. The results were as follows. 1. The development of immature roots was not affected by orthodontic treatment and mostly showed normal root length and apical form. 2. Root length of immature teeth was sustained or became shorter, partially in long treatment duration or with open bite patients. Even though the teeth reached their normal root length, they demonstrated a blunt form. 3. Most of the mature roots showed mild resorption, and the form of mature roots was more blunt than the developed form of the immature roots (p<0.05). 4. The developed form of the immature roots was statistically related to treatment duration, while the form of the mature roots was significantly related to the displacement of incisors (p<0.05). 5. In contrast, other variables such as gender, classification of malocclusion, changes in overbite, and changes of U1 to SN showed no correlation with the root resorption of both groups.

• Journal of Ginseng Research
• /
• v.18 no.2
• /
• pp.134-136
• /
• 1994

The effects of soil phosphorus level on seed emergence, seedling mortality, plant and root development of American ginseng (Panax quinquefolium L.) were evaluated in a newly planted commercial ginseng garden. Phosphorus levels were increased from 58 ppm to 100, 150 and 200 ppm with triplephosphate (0-45-0). Higher phosphate levels increased, seed emergence and reduced seedling mortality. Root length, diameter, fresh root weight and total leaflet length were not affected by phosphate levels.

• Journal of Ginseng Research
• /
• v.3 no.2
• /
• pp.105-112
• /
• 1979

Effect of gibberllin on the breaking of bud dormancy of root and growth of aerial parts were investigated under laboratory and field condition for the prolongation of shoot growth duration, shortening of fruit bearing age and the increase of root yield. Drop application of GA (0.5ml of 50ppm) on rhizome of one year old root broke bud dormancy better than by low temperature. Soaking for one hour of one year old roots which wintered in the field in GA (50-200ppm) greatly accelerated the emergence of new buds while kinetin was only effective at low level (50ppm). GA substantially increased stem length in early stage and petiole length later on while kinetin increased stem diameter. Under the field condition with polythylene film tunnel (PET) in early spring the soaking in GA (50ppm for 1 hour) of rhizome of 4 year old root with replanting and dropping GA (50ppm, 1ml) on rhizome without replanting brought earlier emergence (29days) in comparison with that in the usual field. PET alone caused 14 day-early emergence. GA increased the length of stem and petiole only in early stage and replanting decreased only petiole length in later stage. Soaking in GA with replanting caused the Pronounced decrease in peduncle length, percentage of (ruin set and dry weight of reproductive organ (fruits and peduncle). Dropping without replanting showed significant decrease only in dry weight of reproductive organ. Fruit maturing was 20 days earlier than in usual held with little difference between GA and PET. It is well expected that GA could be used for early emergence of bud, shortening of root dormancy period, thinning of fruit and higher root yield according to application amount and methods.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.7 no.1
• /
• pp.1-7
• /
• 1987

A pot experiment conducted to investigate the root elongation and weight of grasses, i.e. Orchardgrass, tall fescue and perennial ryegrass under the conditions adjusted pH of half vertical part of pot soil to seven levels from 2 to 8. 1. Root growth was drastically decreased as soil pH was lowed. 2. Higer the soil pH, longer the root length. Increase of soil pH to 6 increased the root length of orchardgrass, perennial ryegrass and tall fescue. 3. Regardless of grass species, most of roots distributed to the soil which adjusted pH from 6 to 7. 4. Dry weight of root was increased to pH 7 of soil in orchardgrass and perennial ryegrass and was 55 to 78% of production of pH 6 compared with soil pH 7. In case of tall fescue, dry root weight in the soil pH 7 was 69.8% of root weight growed in soil pH 6.