• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.95-100
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• 1998

Seedling establishment of soybean [Glycine mar (L.) Mer-rill] is an important factor for soybean production in the field. The objective of this study was to determine the distribution of chemical composition in the emerging organs during seedling development in soybeans. Three soybean cultivars (Hill, Paldalkong, and Jangyeobkong) were planted at the Research Farm of College of Natural Resources, Korea University, on May 26, June 5, and June 14. Protein, oil, sugar, and starch contents were measured in each organ at each developing stage. Mean dry weight of three soybean cultivars decreased until VE stage and increased after this stage. Protein content of whole seedling did not change significantly during the seedling growth stage, but the amount in cotyledons markedly decreased with each growth stage increment. About 88% of the cotyledon protein was translocated to the other parts of the seedling at the V2 stage. Oil content of cotyledons sharply decreased until the V1 stage. Sugar content of the seedling was not detected at VE stage and starch content of seedlings increased slightly at VE and VC stages. For the changes of each metabolic component, the amount for whole plants decreased until the V1 stage and started to increase after this stage. The results of this study provide evidence for the breakdown of carbohydrates and oil at the initial stage of seedling growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.309-315
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• 1999

Rice seedling test was conducted to check the loging tolerance at ripening stage through evaluating the root characters. Thirteen Korean and foreign rice cultivars with direct seeding adaptable or high quality characteristics were grown in a cell pot and under submerged paddy. The root characters and pushing resistance of rice hill were determined at seedling and ripening stage, respectively. The diameter of crown root at the 7th and 8th leaf stages was thicker in lodging tolerance cultivars than those of others and showed significant-positive correlation with both pushing resistance and crown root diameter of mature plants. Also, the tensile strength of crown root at the 7th and 8th leaf stage showed highly positive correlation with the tensile strength of crown root of mature plants. The number of crown root at 7th leaf stage was significant-positively correlated with that of mature plant. The diameter of seminal root was not significantly correlated with the diameter of crown root throughout the whole growth stage. These results indicate that the diameter, tensile strength and number of crown root associated with root lodging tolerance can be detected with the seedling at about 7th or 8th leaf stage, and the seedling test using the cell pot is an useful and practical method to select lodging tolerant cultivars or lines of rice based on root characters, especially diameter of crown root.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.230-236
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• 1992

To study the effects of different nursing methods and transplanting on the growth of the rice plant(Oriza sativa L.hn southern region of Korea, Kumo-byeo, Palgong-byeo and Dong-jinbyeo were transplanted from April 20 to July 20 with 15 days intervals as 8 days seedling (infant rice), 25 days box seedling for machine transplanting and 45 days conventional seedling, respectively. No. of leaves at transplanting were in order of 45 days seedling>25 days seedling>8 days seedling. In 25 days seedling, they were increased as transplanting dates were later from April 20 to June 5, and in 45 days seedling, it showed same tendency until June 5 with Dongjinbyeo, June 20 with Palgong-byeo and Kumo-byeo. Root activity according to the $\alpha$-naphthylamine oxidation activity and rooting activity were higher in order of 8 days seedling>25 days seedling>45days seedling. Panicle formation initiated after maximum tillering stage as transplanting at April 20 with 8 days seedling and 25 days seedling, but it intiated before maximum tillering stage as transplanting at July 20 in Kumo-byeo. and in Palgong-byeo intiations of panicle formation were shown after maximum tillering stage as transplanting until May 20, but June 5 in Dongjin-byeo. However, there was no significant tendency with 45 days seedling. Missing hill ratio were less than 5% as transplanting with 8 days seedling and 25 days seedlingregardless of transplanting periods or varieties.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.103-103
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• 2017

Vigorous root growth at the seedling stage in dry direct-seeded conditions is considered as a critical trait because it is involved in seedling emergence, early vegetative vigour, nutrient uptake as well as drought tolerance. In this study, we performed QTL mapping using the recombinant inbred lines obtained from the cross between Tongil-type Dasan and temperate japonica TR22183 (DT-RILs) to identify QTL underlying early root development. TR22183, which was previously reported to have high nitrogen utility and cold tolerance, showed vigorous root growth at the seedling stage in semi-drought conditions. Root length, fresh weight and dry weight of TR22183 were significantly higher than in Dasan. By QTL analysis with genotyping-by-sequencing method, we identified two QTLs for root fresh weight (RFW) in chromosome 7 and root dry weight (RDW) in chromosome 8, explaining phenotypic variances of 13.5% and 10.6%, respectively. These QTLs would be used to develop rice varieties adapted to direct-seeded cultivating system.

• Molecules and Cells
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• v.21 no.2
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• pp.192-196
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• 2006

Salt tolerance was evaluated at the young seedling stage of rice (Oryza sativa L.) using recombinant inbred lines (MG RILs) from a cross between Milyang 23 (japonica/indica) and Gihobyeo (japonica). 22 of 164 MG RILs were classified as tolerant with visual scores of 3.5-5.0 in 0.7% NaCl. Interval mapping of QTLs related to salt tolerance was conducted on the basis of the visual scores at the young seedling stage. Two QTLs, qST1 and qST3, conferring salt tolerance, were detected on chromosome 1 and 3, respectively, and the total phenotypic variance explained by the two QTLs was 36.9% in the MG RIL population. qST1 was the major QTL explaining 27.8% of the total phenotypic variation. qST1 was flanked by Est12~RZ569A, and qST3 was flanked by RG179~RZ596. The detection of new QTLs associated with salt tolerance will provide important information for the functional analysis of rice salt tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.270-274
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• 1997

This experiment was conducted to evaluate the combining ability of japonica rices for improving the salinity tolerance at seedling stage. Nine varieties used in partial diallel analysis included three varieties of each tolerant, moderately tolerant and susceptible one. Twelve-day-old seedlings were grown in saline solution, initially at an EC of 6 dS /m for four days, followed by an EC of 12 dS /m for 20 days. The agronomic characters at seedling stage such as plant height, dry shoot weight and dry root weight were measured to analyze for combining ability of the parents. General combining ability(GCA) and specific combining ability(SCA) effects were highly significant for all tested parameters. However, mean squares for GCA were about five times larger than that for SCA suggesting the preponderance of additive gene action. Among tolerant varieties, Gaori and Namyang 7 were good combiner for improving the salinity tolerance at seedling stage in GCA as well as SCA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.416-423
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• 1997

To obtain the basic information about the translocation of seed reserves of soybean[Glycine max(L.) Merrill] cultivars, 'Hill', 'Paldalkong' and 'Jangyeobkong' , the dry matter changes of emerging organs during the germination and seedling development were observed at the research farm of College of Natural Resources, Korea University, on May 26, June 5 and June 14. Mean fresh weight, dry weight and moisture content of three soybean cultivars were increased until the V2 stage in all seedling parts except cotyledons. Cotyledon dry weight was continuously decreased and the decreased amount at the V2 stage was about 80% of the cotyledon dry weight at the germination stage. Structural component of cotyledons was 22.2% of the cotyledon dry weight at the germination stage. Metabolic components of cotyledons were markedly decreased until V2 stage, and about 91% of cotyledon metabolic components at germination stage was utilized. However, those of whole seedling were increased after the V1 stage. Therefore, it appeared that role of cotyledons as nutrient supplier for germination and seedling growth was important until the V1 stage especially.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.149-153
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• 1999

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.144-144
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• 2022

The amount of required forage is increasing by 20% every year in South Korea, but the cultivation area for forage production is limited. The yield ability of triticale forage is the highest among the winter forage crops including rye and the crop has cold tolerance within the average low temperature of -10℃ in January. Therefore, this study analyzed effects of sowing and harvesting times on feed value and quality for efficiently using and supplying triticale as livestock feed. Seed of the triticales, 'Joseong' was sown in 2021 fall (October) and 2022 spring (March). The triticales were harvested according to growth stages: seedling stage, booting stage, heading stage, 10 days after heading, and 20 days after heading. Moisture contents of each harvested triticales were adjusted to about 60%, and then the triticales were fermented for 40 days at room temperature under anaerobic conditions as silage. We have analyzed pH and organic acid to determine the feed value and quality of each silage. The contents of lactic acid in silage ofthe triticale harvested at the seedling stage of both fall and spring-sown (1.61%, 1.63%) were the highest among all of the silages; the booting stage (0.75%, 1.33%), the heading stage (0.50%, 0.69%), 10 days after the heading stage (0.31%, 0.42%), and 20 days after heading stage (0.22%, 0.40%). Such as the contents of lactic acid in the silages, and the pH value of the silages The pH value in both the fall- and spring-sown became lower as the triticale was grown up: seedling stage (7.05, 6.85), booting stage (6.21, 6.75), heading stage (6.18, 6.28), 10 days after heading stage (6.22, 6.17), and 20 days after heading stage (6.15, 5.81). Taken together, the results showed that the feed value and quality of triticale silage were more affected by harvesting time than sowing time.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.35-39
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• 2002

This study was conducted to investigate the effect of early $CO_2$ enrichment during seedling stage on long-term $CO_2$ enrichment after transplanting in the culture of pat-choi (Brassica campesris L), spinach (Spinacia oeracea L.), and leaf lettuce (Lactuca saliva L). During seedling stage, $CO_2$enrichment had significantly higher fresh and dry weight and leaf area of the top parts (above ground) of all three plant species than the control (no $CO_2$ enrichment). About 53%, 70% , and 40% increase in fresh weight of the top parts of pak-choi, spinach, and leaf lettuce were observed, respectively. Also, in seedling stage, dry weights of roots of spinach and leaf lettuce were significantly increased by early $CO_2$ enrichment. Relative fresh weight increment, compared with fresh weight of the control, in the top parts of roll three plants showed the highest values in 10 days after $CO_2$ enrichment treatment. In the long-term $CO_2$ enrichment experiment, early $CO_2$ enrichmented plants had 20% greater leaf area than the control in all three leafy vegetables. Fresh and dry weights of top parts of early $CO_2$-treated plants were also increased from 10 to 20%, as compared with the control plants. However, these increasement rates in the long-term $CO_2$ enrichment were lower than those seedling stage, which had 30-60% increment-rates. After transplanting, photosynthetic rate of each leafy vegetable in the control treatment slowly decreased, but those rates of early $CO_2$ enriched plants rapidly decreased.