• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.6
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• pp.539-542
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• 1990

This experiment was conducted to obtain some informations on the effects of number of leaf harvest and time to agronomic characters and grain yield in perilla. For the experiments perilla seedlings of 40days old were transplanted on June 20, July 20 and August 20 in 1988, and leaf harvested at 30. 40. 50 and 60 days after transplanting, respectively. The following results were obtained from the experiments. In the case of the fully developed leaves were harvested, culm length were decreased by more harvests and by the later harvests. However culm diameter, number of nodes and branches were little influenced by the leaf harvests. Number of clusters, weight of 1,000 grain and grain yield were significantly influenced by the number of leaf harvest and time. As the above results, considering the grain yield, leaf harvest would be available in the case of once or twice at the early growing stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.54-58
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• 1992

In order to determine the optimum planting density of Sickle Senna (Cassia tora L.), agronomic characters, yield components and grain yield were investigated under vinyl mulching and non -mulching condition. The characters, stem length, stem diameter, number of branches, number of pods per plant, number of pods per m$^2$, and number of grains per pod, etc., were excellent under the vinyl mulching condition, and number of pods per m$^2$ was the highest in 60$\times$15cm planting space under vinyl mulching or non-mulching. Both of the weight of 100 grains and grain yield were also higher under the vinylmulching condition, and grain yield was the most excellent in 60$\times$15cm planting space under the vinlymulching, or non-mulching. Under the vinyl mulching and non-mulching, the analysis of variance for agronomic characters following the difference of planting density, were acknowledged to be worth of attention.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.191-195
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• 2003

This study was conducted in 2001 to develop a technique for mass production of superior seed tuber by using a wick culture system as an alternative plan to solve problems in hydroponic culture of potato. Potato (Solanum tuberosum L. cv. Dejima) plug seedings were planted on a styrofoam bed (volume $0.032\textrm{m}^3$) containing two different media (Jeju scoria + peatmoss and perlite + peatmoss, (1:2, v/v) mixture, respectively). Each bed was equipped with various number of wicks (2, 4, 6, 8 and 10 ea/bed). After harvest, the total porosity of both media was 83-85%. Bulk density of Jeju scoria + peatmoss was higher compared to that of perlit + peatmoss. However, the number of wicks did not influence to the bulk density. Conversely, moisture capacity of Jeju scoria + peatmoss was remarkably greater than that of perlite + peatmoss and was increased from 55 to 70% as elevating number of wicks. Although the number of wicks resulted in the areal growth of plants, the total yield and the weight of tuber were highest at the bed equipped with six wicks in both media.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.425-431
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• 1993

Temperature effects on the grain filling of winter barley(CV. Gangbori, Olbori and Suwon 18) were studied in controlled environments under three day /night temperature regimes (viz. 25/20, 20/15 and 15/10$^{\circ}C ) and at three stages of development, viz. Vegetative, spike development and grain filling stages. Physiological maturity times to the temperature regimes were observed at 53 to 57 days after heading at 15/10$^{\circ}C , 43 to 45 days and 32 to 33 days at 20/15$^{\circ}C and 25/5$0^{\circ}C$, respectively. When plants were grown in 25/20$^{\circ}C during the spike development stages, the number of spikes per plant and grains per spike decreased by 39% and 41% respectively compared with 20/15$^{\circ}C of day / night temperature. The effect of high temperature on grain weight was not significant in all growth phases except post-anthesis where grain weight decreased by 30%. Therefore, the most important temperature effects were round during the spike development stages.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.143-150
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• 2003

This study was conducted to determine the response of main growth characters, yield and chemical composition of Jeju native soybean based on the difference between phosphate rates (0, 50, 100, 150, 200, 250kg/ha) from May 11 to September 10 in 2002 in Jeju island. Days to flowering was delayed from 92 days to 97 days as the increasing of phosphate rate. Also plant height grew longer from 109cm to 124cm. The number of branches and leaves, stem diameter, root length and weight of root grew powerful as phosphate rate increased from 0 to 250kg/ha. Fresh forage yield was 26.5MT/ha in the nonphosphate plot and then was 36.9MT/ha as phosphate rate increased to 250kg/ha. And the difference between 200kg/ha and 250kg/ha in phosphate rate was not significant. Dry matter, crude protein and TDN yield increased 6.0∼7.9MT/ha, 0.9∼1.4MT/ha and 3.4∼4.9MT/ha respectively, as the increasing of phosphate rate. Also crude protein, crude fat, NFE and TDN content increased 15.5∼18.3%, 2.2∼3.3%, 42.5∼43.5%, and 56.7∼61.9% respectively. In contrast with this, crude fiber and crude ash decreased 32.1∼28.1% and 7.7∼6.8% respectively. To reach the climax of forage yield was estimated optimum phosphate rate to be 200kg/ha.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.135-142
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• 2003

Jeju native soybean was grown at five plant densities(30${\times}$30cm, 30${\times}$25cm, 30${\times}$20cm, 30${\times}$15cm, 30${\times}$10cm) from May 11 to September 10 in 2002 in Jeju island to determine the optimum plant density. Days to flowering was delayed from 94 days to 98 days as increasing of plant density. Plant height was 103cm at 30${\times}$30cm plot, as plant density increased, was 117cm at 30${\times}$10cm plot. As plant density increased, the number of branches and leaves, stem diameter, weight of plant, root length and weight of root grew low. As plant density increased from 30${\times}$30cm to 30${\times}$15cm, fresh forage, dry matter, crude protein and TDN yield increased 23.3∼36.5MT/ha, 5.1∼8.0MT/ha, 0.8∼1.4MT/ha and 2.9∼4.8MT/ha respectively, but decreased at 30${\times}$10cm plot. As plant density increased, crude protein, crude fat, NFE and TDN content increased 16.2∼17.9%, 2.7∼3.7%, 37.6∼40.7% and 56.1∼60.0% respectively. In contrast with this, crude fiber and crude ash decreased 34.9 ∼30.8% and 8.6∼7.2% respectively. To reach the climax of forage yield was estimated optimum plant density to be 30${\times}$15cm.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.478-490
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• 2021

We aimed to generate basic breeding data for melon (Cucumis melo L.). A total of 219 melon accessions conserved at the National Agrobiodiversity Center (NAC) in Rural Development Administration (RDA) were used in this study, of which 72 (33%) were collected from India. The majority of accessions showed orange (42%) and white (36%) flesh color. In addition to phenotypic evaluations, the accessions were genotyped using a molecular marker for the carotenoid biosynthesis gene CmOr. DNA fragments of the expected size were amplified in 205 out of 219 accessions. Digestion of the PCR products with HinfI restriction endonuclease showed 100% concordance between phenotype and genotype in green-fleshed accessions, but 98%, 97%, and 80% concordance in orange-, white-, and creamy-fleshed accessions, respectively. Sequence analysis revealed single nucleotide changes in the three positions of SNP1, SNP2 and SNP1int in the CmOr gene among accessions. These newly found alleles suggest that there are multiple mechanisms in determining fruit flesh color in melon. Also, the phenotype data of diverse accessions obtained in this study will be a valuable source for melon breeding.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.131-142
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• 1975

This study was carried out to define the variations of important quantitative characters and correlations among them accoding to the planted location under the shadow by planting density. The results obtained are summarized as follows; 1. Growth of leaf and stem of 6 rows and 8 rows planting plots was decreased at front and back rows, but that of root was increased at front row and also decreased at back row. However, at 4 rows planting plots, front row was better for the growth of leaf, stem and root. 2. Average root weight of 6 rows planting plot was 34.29g but that of 8 rows planting plot was ]8.20 g. And total weight of root per unit area was increased and quality of ginseng was better in 6 rows planting plot compaired with 8 rows. 3. Variation by planting locations under the shadow was smallest in stem diameter and highest in root length at 8 row planting plot, but at 6 rows planting plot, that was smallest in leaf blade and greatest in stem length. However, in 4 rows plant ing plot, variation of leaf length was smallest and that of root weight biggest. 4. In all Planting densities, root weight was significantly correlated with root diameter and high correlation was recognized between root diameter and stem diameter. 5. Rate of variations of all characters among plant individuals was different by planting location and that of correlations between quantitative Characters too.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.296-302
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• 2017

Rice (Oryza sativa) cultivars show an impairment of growth and development in response to abiotic stresses such as drought, salinity, heat and cold at the early seedling stage. The tolerance to heat stress in plants has been genetically modulated by the overexpression of heat shock transcription factor genes or proteins. In addition to a high temperature-tolerance that has also been altered by elevating levels of osmolytes, increasing levels of cell detoxification enzymes and through altering membrane fluidity. To examine the heat tolerance in transgenic rice plants, three OsOPT10 overexpressing lines were characterized through a physiological analysis, which examined factors such as the electrolyte leakage (EL), soluble sugar and proline contents. We further functionally characterized the OsOPT10 gene and found that heat induced the expression of OsOPT10 and P5CS gene related proline biosynthesis. It has been suggested that the expression of OsOPT10 led to elevated heat tolerance in transgenic lines.