• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.278-285
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• 2008

An efficient transformation method for soybean [Glycine max (L.) Merr.] using meristematic tissues of germinating seeds has been established. The embryonic axes were excised from germinating seeds of Korean soybean cultivar, Iksannamulkong and 0.5-2 cm long segment containing meristematic tissues were prepared by cutting hypocotyl region. The explants were inoculated with Agrobacterium tumefaciens strain LBA4404 harboring a binary vector with the bar gene as a selectable marker gene and a ${\beta}-glucuronidase$ (GUSINT) reporter gene, and then co-cultured for 7 days on co-cultivation medium (CCM). The meristematic tissues were cultured on shoot induction medium (SIMP6) supplemented with 0.4 mg/l $N_6-benzylaminopurine$ (BAP) and 0.1 mg/l indolebutyric acid (IBA) in the presence of 6 mg/l L-phosphinotricin (PPT) for 2 weeks and the surviving explants were transferred to shoot elongation medium (SEMP6). Transformation was confirmed by Southern blot analysis and the transformation efficiencies ranged from 1.48 to 2.07%. The new modified transformation method was successfully implemented for obtaining several transgenic lines with SMV-CP gene. It is expected that this method could efficiently be used for the transformation of recalcitrant soybean cultivars.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.527-539
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• 2023

Pepper (Capsicum annuum L.) is an important vegetable and spice crop that has been cultivated worldwide. Pepper fruits have unique taste and aroma, providing a variety of antioxidants and compounds important for human health, which makes a high economic value. In addition, there is a high demand for new pepper varieties, according to consumer's preference. However, pepper is a recalcitrant plant for in vitro tissue and organ differentiation and plant regeneration, which makes it difficult to develop demanded varieties using newly developed technologies such as genetic engineering and gene editing. In this study, tissue culture and regeneration conditions were investigated using seven pepper varieties that were obtained from the core-collection of Seoul National University. We observed callus and bud induction and shoot formation using several media composition composed of different cytokinins and auxin concentrations. As a result, it was found that there were differences in callus induction and shoot formation of each variety depending on the hormone composition, and the highest regeneration was shown when the medium containing Zeatin Riboside and the petioles of seedlings were used. In particular, out of seven pepper varieties, CMV980 exhibited a higher regeneration efficiency (approximately 48%) than other varieties, followed by Yuwolcho. Therefore, this study provides CMV980 and Yuwolcho as good candidates that can be used for pepper transformation, which might contribute to the development of various varieties through gene editing technology in the future.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.406-411
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• 2006

New Guinea impatiens (Impatiens hawkeri) shows very sensitive responses to different light conditions. Due to these phenomena, testers of DUS (distinctness, uniformity and stability) for granting plant variety protection right often have problems distinguishing genetic or physiological differences. New Guinea impatiens 'Fishlimp 149' was grown under several light intensities in a rain-sheltered vinyl house to observe differences of plant growth and flowering. As compared with the control (avg. $1,010{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$), treatments of shade-1 (avg. $599{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and shade-2 (avg. $88{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) showed increased plant height, plant width, leaf size and pedicel length. On the contrary, these growth parameters decreased in shade-3 (avg. $30{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) with the lowest light intensity. Shade-1 treatment enhanced flower characteristics such as flower diameter, upper petal width, side petal width and lower petal length. However, these characteristics were suppressed by lower light intensities than that in shade-1. Anthocyanin contents of shoot, leaf and pedicel decreased with increasing shading, but that of flower petal was the greatest of the shade-1 treatment. Shade-1 treatment showed the greatest Hunter a value analyzed by a colorimeter, and L and b values increased with increasing shading. Shade-1 treatment seemed to be provided the most proper light condition for DUS test of New Guinea impatiens. Additionally, anthocyanin accumulation on New Guinea impatiens during DUS test was due to not genetic differences but physiological phenomenon.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.227-234
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• 2017

This study aimed to investigate the nutrient solution developed by based on nutrient-water absorption rate of strawberry 'Maehyang' by comparing growth and yield for 8 months with 5 kinds of nutrient solution with different ion composition. Strawberry plants were planted at elevated bed and supplied with five kinds of nutrient solutions (RDA), Yamazaki, PBG, University of Seoul (UOS) and NewUOS from one month onwards. Five types of nutrient solution were supplied to the strawberry plants associated with EC $1.0dS{\cdot}m^{-1}$, pH 6.0, $150{\sim}300mL{\cdot}plant^{-1}$ per day. At 60 days after planting, leaf width and leaf petiole of the strawberry plants showed significant differences among nutrient solution types and photosynthesis was higher in RDA and NewUOS nutrient solution and lower in PBG nutrient solution. The EC of the drainage on vegetative growth stage was $0.7{\sim}0.8dS{\cdot}m^{-1}$, which is lower than the supplied EC level, and to $1.0-1.2dS{\cdot}m^{-1}$, afterwards. The pH of the drainage was higher in Yamzaki solution as 6.2~6.8, while the pH of the UOS nutrient solution was lower in 5.1~5.2. Nitrate content was most absorbed in vegetative growth stage and after flower clusters development. The potassium uptake was highest at the NewUOS followed by UOS and Yamazaki nutrient solution. At six months after -planting fresh weight and dry weight of shoot and root were higher in UOS and NewUOS nutrient solution than other nutrient solutions, and the dry matter ratio was lower at 43.5% in Yamazaki nutrient solution and 30.6% in NewUOS nutrient solution than other solutions. Length, width, weight, and sugar content of the strawberries harvested from December to February were unaffected by treatment, but yield was higher in NewUOS nutrient solution due to increasing fruit number and average weight. From March to May, number of fruit was higher in Yamazaki nutrient solution. In conclusion, there was no difference in the growth of 'Maehyang' when 5 nutrient solutions were grown under hydroponics. But in order to improve the marketability, the NewUOS nutrient solution is appropriate to use from planting to February and it is suitable to use Yamazaki nutrient solution after March when temperature is high and the amount of fruit set per inflorescence.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.441-451
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• 2019

This study was conducted to investigate the crop characteristics of 181 sweetpotato germplasms collected from Korea and overseas. The longest shoot vine length was observed in IT232211 (354.8 cm) and the shortest shoot vine length was observed in IT232185 (32 cm). The maximum numbers of shoot branches and nodes were produced by IT232091 (23.0) and IT232174 (67.8), respectively. Differences in Rapid Visco Analyser profiles were observed for pasting parameters such peak, trough, final, breakdown, and setback viscosities; and pasting temperature. The peak and breakdown viscosities were highest in IT232050 and IT232010, at 338.3 and 207.2 Rapid Visco Unit (RVU), respectively. The trough viscosity was lowest in IT232019 at 103.8 RVU. IT232101 had the highest final viscosity (284.6 RVU), and IT232192 had the highest setback viscosity (81.7 RVU). IT232197 had the highest pasting temperature at 86.8℃, and that of IT232134 was lowest at 72.7℃. To evaluate functional substance content, we analyzed 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and total polyphenol content. The highest frequency proportion of starch was in the 10%-15% range (50.8% of the plants), followed by the 5%-10% range (38.1% of the germplasms). Sugar content ranged from 13.5 to 33.3% (23.2% on average); the highest frequency proportion of sugar was in the 20%-25% range (56.9% of the germplasms), followed by the 25%-30% range (25.4% of the germplasms). The highest frequency proportion of water was in the 70%-80% range (52.5% of the germplasms), followed by the 60%-70% range (44.2% of the germplasms). Our results provide basic data for the selection of useful resources and for the development of new sweetpotato varieties.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.43-54
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• 1986

This study was carried out to investigate the influence of light intensity on the growth of Korean white pine (Pinus koraiensis) seedlings. The seedlings were grown under four different relative light intensities: 100%, 63%, 37%, and 19% of full sunlight by covering with saran screen on seed bed. The results obtained were summarized as follows; 1. The highest shoot elongation was found at 37% in relative light intensity (RLI) plot, and the best growth in root, seedling length and diameter increment appeared at 100% on RLI plot. Contribution rates of shading to growth in shoot elongation, root growth, seedling length, and diameter increment were 9.3%, 26.2%, 21.0%, and 48.7%, respectively. 2. The greatest number of one-year-old needle fascicle was found at 100% in RLI plot, whereas that of two-year-old needle fascicle appeared at 37% in RLI plot. The contribution rate of the light intensity to number of needle fascicle was 3.9% and factor of leaf age contributed to number of needle fascicle in 27.8%. The length of needles grown under different light intensities varied with needle ages. The longest length of new needles appeared at 37% in RLI plot, but old needles were not clear in influence of light intensity. The contribution rate to needle length by the light intensity was 2.5%. 3. The heaviest value of the fresh and dry weight of seedlings appeared at 100% of RLI plot then decreased with light intensity. The contribution rates to fresh and dry weight by the shading were 38% and 7.6% respectively. 4. The largest value of the dry weight of needles appeared at 100% of RLI plot and then decreased with light intensity. The contribution rates to dry weight of needles by the light intensity was 13.18%. 5. The values of T/R ratio increased with decreased light intensity and the contribution rate was 7.0%. 6. Positive correlation and linear regressions were recognized between dry weight of leaf and other factors (dry weight of shoot, root, seedling and diameter increment).

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.125-154
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• 1972

The major purpose of this survey is to collect the related information on technical aspects for solving the problems which are facing producing farmers and regions, provide scientific facts to farmers related personals and institutions and aimed at contributing the development of sericultural sector in Korea. The results are as follows; (1) The area of mulberry field per a farmer which was selected as sample ranges from 3.0 to 370a with its average 45. 1a. And yet, the average of new cultivated areas is above than that of ordinary ones by 56.3 to 33.8a. The largest area is Honam hill area with 101. 1a and e smallest is Muzinzang with 20.8a. Shortly, a large number of farmer belongs to 11 to 50a with 66.5 per cent. (2) The ratio of clay and loam soils which are inadequte for growing of mulberry trees is 28.3 per cent and particulary high in new cultivated area with 36.2 per cent. And yet, base soil is occupied with 45 per cent of heavy clay and particularly even 54.2 per cent in new cultivated area. On the other hand, the number of areas which the contents of organic matters is relatively low, with 48.2 per cent is near the half, but the ratio of mulberry fields which seems to contain organic matters abundantly is only 7.2 per cent. (3) The varieties of mulberry trees are Ilgirae, Gaeryangseoban, Suwonsang No.4 and Nosang. The ,ratio of the varieties are 33.3%, 25.7%, 18.0% and 10.5%, respectively. Consequently the four varieties enumerated above occupies 93.5 per cent. (4) The mulberry fields are almost composed of exclusive mulberry fields and its ratio was 92.3 per cent. The number of planted trees per 10a arrange from 480 to 1,390 and its average is 846. But most of them nearly belong to 701 to 1,000 with 91.3per cent. (5) The second year's autumn after planting is generally adopted as the first harvesting season, and its ratio is 73.0 per cent, but autumn of the years and next spring are not few, and its ratio are 12.7 and 8.7 per cent. The first harvesting method is relatively normal with 88.8 per cent of ratio. From the viewpoint of harvesting method, picking leaves was applied with 97.7 per cent of ratio in young larvae rearing and picking shoot and picking shoot after harvest with branches were applied with 80.0 per cent of ratio in grown larvae rearing. The ratio of applying the harvesting method of picking leaves were 97.7 and 91.7 per cent in young larva and grown larva in autumn rearings. But there was also picking leaves absolutely with 7.1 per cent of ratio(Chunwon was 47 per cent) and yet, the farmers applying cutting before shooting in spring was no more than 17.8 percent.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.306-310
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• 2011

This study examined the changes in the distribution of nitrogenous compounds in various parts of 3- and 4-year-old persimmon (Diospyros kaki cv. Fuyu) with fruits (fruited) and without fruits (defruited). The effect of the changes was then related to the storage and their reutilization for new growth in the following year. From June 15 to November 1, the partitioning of amino acids among perennial parts of fruited trees was inconsistent, whereas that of defruited trees was characterized by a significant increase. Compared with the fruited trees, amino acids accumulated in the perennial parts of defruited trees were 1.66 g and 3.48 g more in 3- and 4-year-old trees, respectively. Of the total proteins increased during this period, the proportions distributed to the perennial parts of the tree were less than 50% for fruited trees, but they were more than 90% for defruited trees. Roots were the strongest sink for proteins; percent proteins in the roots amounted to 94 in defruited 3-year-old trees and 76 in 4-year-old trees. Compared with the proteins accumulated in perennial parts of fruited trees, those of defruited trees were 1.64 g more in 3-year-old and 2.58 g more in 4-year-old trees. During this period, the nitrogenous compounds decreased by 0.50-0.56 g in the leaves of fruited trees, while they increased by 0.66-0.78 g in their fruits. During the new growth from April 10 to June 10 of the following year, amino acids decreased both in the fruited and defruited trees. Proteins, especially in the root, decreased in the trees that had been previously defruited. More amino acids and proteins were found in the newly grown parts of the defruited trees. Compared with the fruited trees, the defruited trees accumulated nitrogenous compounds more in roots than in the other parts of the perennial parts. The reserve nitrogenous compounds contributed to the new shoot growth and fruit set in the following year.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.306-312
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• 2017

This study was carried out to develop new hybrid zoysiagrass cultivar 'Seah' (The application no. for cultivar protection : 2014-22). Native zoysiagrasses were collected from south-west seaside of Korea from 2010 to 2011. Artificial crossing was conducted to develop F1 hybrid between Z2011 (Z. sinica) and NM1 (Z. matrella) at plastic house in 2011. Among the progenies, 'Seah' showed fine leaf texture and high shoot density from the space planting plots at field. 'Seah' showed genetically light green color, with fine leaf with 1.8mm and height to the lowest leaf blade was 1.94 cm. Ground coverage rate was slower than medium leaf zoysiagrass (Jung-gi), but plant height of 7.1 cm was the lowest among the compared zoysiagrasses and height to lowest leaf of 1.94 cm was lower than most zoysiagrass, which may allow low mowing height.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.100-106
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• 1995

This study was conducted to find the factors affecting somatic embryogenesis in suspension culture of Rehmania glutinosa and investigate the possibility of artificial seed production by encapsulation of somatic embryos. Linsmeier-Skoog medium was appeared as proper for somatic embryogenesis. Sucrose with $3{\sim}5%$ as carbon sources was good for somatic embryogenesis, and both ammonium and nitrate nitrogen were necesary for normal somatic embryo production. BA with NAA or kinetin with NAA were better than the use of cytokinin alone for both somatic embryogenesis and numbers of somatic embryos. $AgNO_3$ as protectant for vitrification of seedlings in vitro culture had no harmful effect on somatic embryos. Sphericity of encapsulated seeds was good at 3% gel of sodium alginate but germination was better at 2.5% sodium alginate level. Artificial seeds were germinated and developed normal shoots and roots under in vitro condition.