• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.43-47
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• 2001

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi and seonmi, whose source and sink are different one another, were cultivated at different amount of fertilizers, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem, leaf and tuberous root weight by amount of fertilizer and defoliation rate of sweet potato varieties was different. Stem and leaf weight increased along with heavy dressing by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number was the most at $N-P_2O_5-K_2O=60-70-190kg/ha$ amount of fertilizer, showing seonmi the most number. The number of stem, leaf and tuberous root increased along with the lowered rate of defoliation. In case of $N-P_2O_5-K_2O=20-30-90kg/ha$ amount of fertilizer, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem, leaf and tuberous root number was low as defoliation rate increases. The total dry weight matter was the most at heavy dressing amount of fertilizer.

• Journal of Environmental Science International
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• v.11 no.11
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• pp.1165-1172
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• 2002

The effects of salicylic acid(SA) and water deficit on growth and proline accumulation were investigated in cucumber(Cucurmis sativus L.) seedlings. Exogenous application of SA(100 $\mu$M-1 mM) led to a noticeable decrease in root and shoot growth, and dry weight of seedlings. Anatomical observation on leaf of cucumber revealed that the thickness of all leaf tissue components decreased in SA-treated plants. The effect was most pronounced on the width of the adaxial epidermis. In the separate effects of SA(0, 100, 500 and 1000 $\mu$M) and water deficit induced by PEG(0, 4.4, 7.0 and 9.6 %) on growth, the water deficit treatments had greater effects on growth traits than SA. Combinations of SA and PEG(SA+PEG) decreased shoot and root dry matter, and root length. Proline increased slightly in SA-treated seedlings, but exhibited a marked increase in water deficit application. Combinations of SA+PEG induced higher proline in both shoots and roots than SA stress alone. Shoots had higher proline than roots. Our data support a role of SA potentiating the osmotic stress response of germinating cucumber seedling.

• Journal of Ginseng Research
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• v.15 no.1
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• pp.36-40
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• 1991

A field experiment was conducted to examine the growth of one and two year old American ginseng (Panax guinguefolium L.) in the arid interior of British Columbia, Canada. For both years of plants, early season growth was characterized by rapid stem and leaf dry matter production. Root growth commenced in early June and continued until early September. One year old roots had a dry weight of 0.1 to 0.2g at the end of the growing season. The two years old roots commenced the growing season at 0.Is and increased in dry matter by a factor of ten-fold. Dry to fresh weight ratios for both years were similar for root, leaf and stem samples at the end of the growing season. Leaf area index for both years showed similarities in progression over the growing season. As a consequence of the effectiveness of the microclimate modification employed to permit American ginseng cultivation (elevated shade cloth and surface mulch), plant growth and development was extremely good. This indicates the potential for the cultivation of American ginseng in dryland environments.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.187-193
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• 2013

Dry matter allocation characteristics of Calystegia soldanella, grown in pots, was analysed to assess its plasticity in response to water-stressed conditions. As water was withheld leaf water potential between the two watering treatments was similar during the first 6 days, followed by a rapid decrease in water-stressed plants. The minimum leaf water potential was -1.50 MPa on day 15 and the maximum leaf water potential was about -0.5 MPa on day 0 in water-stressed plants. In well-watered plants leaf water potential was maintained almost consistently throughout the experiment. There was no significant difference in plant dry weight between the two watering treatments for 9 days after the start of experiment and that was remarkably increased thereafter, compared with that remained without any increase in water-stressed plants. In dry mass partitioning, however, the water-stressed plants showed a great plasticity, showing that there were 1.81, 1.35 and 0.81 times increase in root, stem and leaf, respectively. Dry mass partitioning in well-watered plants varied from 2% to 5%. The difference of dry mass partitioning between the two watering treatments was reflected in leaf mass per unit area (LMA) and root/shoot (R/S) ratio. LMA in water-stressed plants was lower than that in well-watered plants, while R/S ratio in water-stressed plants was higher in well-watered plants. This means that the water-stressed plants reduced its leaf area and increased dry mass partitioning into root and stem during the progress of soil drying. These results indicate that Calystegia soldanella inhabiting in sand dune cope with water stress with high plasticity which can adjust its dry mass partitioning according to soil water conditions.

• Journal of Microbiology
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• v.42 no.1
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• pp.60-63
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• 2004

A sucrose-agar globule (SAG) was newly introduced to increase production of the vesicular arbuscular mycorrhizal (VAM) fungal spores, Gigaspora gigantea and Glomus fasciculatum. An SAG inoculum and a sucrose-agar globule with root exudates (SAGE) inoculum were prepared, and their spore productions were compared with a soil inoculum. When the SAGE was used as the inoculum on sucrose-agar medium plates the number of spores was increased (35% more than the soil inoculum). After the soil inoculum and SAGE were inoculated on an experimental plant, Zingiber officinale, the percentage root colonization, number of VAM spores, and dry matter content were analyzed. It was observed that the SAGE showed a higher percentage of root colonization (about 10% more), and increases in the number of spores (about 26%) and dry matter (more than 13%) for the two VAM fungal spores than the soil inoculum. The results of this study suggested that the SAGE inoculum may be useful for the mass production of VAM fungi and also for the large scale production of VAM fungal fertilizer.

• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.33-38
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• 1965

It has already been noted that some tree species, denoted as tolerant species, endure to behavior shadiness in growth than those species, denoted as intolerant species, since this fact of tolerance must be involved in silvicultural practice, the present author, with pinus rigida, pinus Thunbergii, and Buxus koreana, investigated the relation of degree of shadiness to soil moisture condition. Because tolerant and intolerant trees must be considered from the standpoint of their ability to use any of the factors that are likely to be at low concentration in the dense or open forest. The observed results may be summarized as follows : 1. The ability of tolerance of the species to shadiness is differently concluded by the base with which the analysis was made, i.c. Height, growth, diameter growth, T-R ratio or dry matter increase and so on. Regarding this point root collar increment or dry matter increase were considered more reasonable bases for discussing the tolerability. 2. When total length growth, including both stem and root, is taken as standard for the comparison of the ability of tolerance for each species, higher soil moisture condition and thicker shadeniss lessened the ability of pinus rigida, seedlings. Pinus Thunbergii, showed. However more moisture resistant than pinus rigida. Buxus koreana, seemed to have stronger ability of tolerance than any others. 3. When total dry matter content taken as standard, the results obtained are given in Fig, 3. In pinus rigida, the soil moisture supplemented the lack of light.

• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.120-124
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• 1999

This experiment was carried out to get basic information on growth characteristics in the cultivation of Saururus Chinensis Baill. The results obtained were summarized as the follows. Growth of shoot was highest at 165 days after planting, percentage of dry matter and leaf area index(LAI) were highest 29% and 4.04 at 165 days after planting. Growth of root tuber was increased until 165 days after planting, after diminished. Dry matter weight of root tuber was highest of 961g/m$^2$ at 180 days after planting and percentage of dry matter was highest of 26% at 150 days after planting, after was stabilized. CGR, RGR, and NAR were higher at 150 days afterplanting. After 165 days after planting, increment of CGR and RGR diminished and NAR decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.38-43
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• 1998

This study examined root growth and distribution under the direct seeding of rice cultivars developed in Korea, Japan, and the U.S. Cultivars from the U.S., especially 'M202' and 'Caloro', had a high ratio of the dry matter partitioning for root and top plant components. Caloro had high root and top growth. 'Koshihikari' from Japan showed the lowest ratio of R/T (root/total dry matter) due to the small amount of root and top plant growth. Most Japanese cultivars except transplanted 'Hatsuboshi' showed low ratio of R/T. Patterns of root distribution for each soil block were recorded by the root box-pin board method. Roots of all cultivars were distributed in blocks A, C, and E in the middle of box, i.e., just below the plant base. Roots of 'Dongjin', M202, and Caloro were distributed deeper than the others. Roots of transplanted Hatsuboshi developed much better than direct seeded Hatsuboshi. Total root weight density was highest in Caloro followed by Dongjin, 'Gancheok', 'Calrose', and the others. The root density of Caloro was twice as much as those of the others except Dongjin. According to cumulative percentages of root distribution on each soil layer, roots of most cultivars were distributed below 20cm. The U.S. cultivars showed vertically well developed root systems as compared to others. A large amount of roots were distributed in the top 15cm of soil layer for Hatsuboshi and Koshinikari, and their root systems appeared to be shallow. In contrast, the rates of root distribution in the top 10cm of soil layer were low for Dongjin, Calrose, and Caloro. These cultivars had relatively deep root systems.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.230-230
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• 2017

About 200 rice varieties for irrigated and rainfed lowland ecosystems were released in the Philippines, which were bred for improving yield under favorable conditions. Root plasticity plays key roles in maintaining crop productivity under abiotic stressed conditions. We hypothesized that some of these varieties possess root plasticity traits in response to water stressed conditions. This study aimed to evaluate the root system development and dry matter production of 14 randomly selected rice varieties (6 irrigated lowland and 9 rainfed varieties) under progressive drought (PDR) and soil moisture fluctuations (SMF) stress conditions. Two experiments were done in rootbox and line source sprinkler systems (LSS). Each of the varieties was subjected to well-watered (WW), PDR and SMF conditions during vegetative stage in rootbox system while the same genotypes were subjected to different intensities of drought stress under LSS. Under rootbox system, PDR and SMF significantly reduced shoot dry matter production in all varieties relative to their WW controls. Among varieties, NSIC Rc238 (irrigated lowland) showed the least reduction in shoot dry weight (SDW) in both PDR (by 11.8%) and SMF (by 26.9%) conditions. Less reductions in SDW of NSICRc238 were partially attributed to the promotion of L-type lateral roots, thus increasing total lateral root length by 24.2% and 30.7% under PDR and SMF, respectively. In LSS, SDW of NSIC Rc238 under mild drought stress (16-21% soil moisture content (SMC) had 31.8% reduction relative to its WW control (${\geq}22%SMC$) and had lower sensitivity drought index. Compared with the IR64 susceptible check and NSIC Rc9 tolerant check, NSIC Rc238 had higher SDW by 90.8% and 38.6%, respectively. Furthermore, no rainfed lowland varieties included in the experiment performed well under different water stress treatments. The results implied that some other irrigated lowland rice varieties may also possess drought dehydration avoidance root plasticity traits under water-stressed growing environments.

• The Korean Journal of Ecology
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• v.15 no.3
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• pp.297-309
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• 1992

The growth of digitaria adscendens and eleusine indica, annual weeds common in japan, was experimentally analyzed under varying untrient conditions. compared with e. indica, d. adscendensshowed a higher the two under high nitrogen availability. Higher net assimilation rate(nar) in d. adscendens than e. india was responsible for high RGR in D. adscendens under the low nitrogen availability. The different of NAR in the two species was induced not by leaf nitrogen content but by nitrogen use efficiency. Under unfertilized conditions nitrogen uptake rate(nur) was greater in d. adscendens than e. indica. Specific absorption rate in two species was similar, but root mass was greater in d. adscendens than e. indica.d. adscendens allocated more dry matter to roots than e. india earlier stage of seedlings. The contributed to higher rot mass and in turn resulted in higher nur in d. adscendens than that in e. india. It is concluuded that the larger allocation of dry matter to roots at early seedling stage in d. adscendens plays an important role in obtaining nitrogen for the continuation of growth under low nitrogen availability.