• Journal of radiological science and technology
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• v.33 no.2
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• pp.143-148
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• 2010

This study is to analyze effects of the growth of Chunhyang Young Radish (CYR) and Altari Radish (AR) according to the exposure for 31 days at low dose ${\beta}$-rays. This test has one contrast sample and eleven test samples each as to AR and CYR. The seeds from contrast and test sample were planted in the culture soil after 8 seeds were chosen from each with identical condition. The accumulated dose of test samples has been measured at consistent time on a daily basis for 31 days. The growing process and germination have been measured twice at consistent time in each week. The number of leaves, length of first leave and weight have been acquired average value by measuring for 20 and 25 days, respectively after being planted. The result of test sample in case of 25 days shows that 5% increase in length and 36% increase in weight for AR each at accumulated dose 0.01 Gy compared to the contrast sample. And the length of CYR has increased by 13~17% and 1% at accumulated dose 0.01~0.08 Gy and 0.3 Gy compared to the contrast sample. For the weight at accumulated dose 0.05 Gy and 0.23 Gy has increased by 36% and 2% compared to contrast sample. As to the number of leaves, AR has increased by 0~50% at accumulated dose 0.01-0.32 Gy compared to contrast sample. It also shows that the CYR has increased to 0~67% at accumulated dose 0.01-0.62 Gy compared to contrast sample. As a result of this study, it indicates that both AR and CYR has generally increased in their length, weight, and the number of leaves at low level accumulated dose part 0.01~0.2 Gy. The size of cell, area of nucleus and density of cell for test sample has been observed quite similar to the ones from contrast sample through microscope. In conclusion, AR and CYR irradiated by ${\beta}$-rays have estimated that they are achieved a rapid growth at low level accumulated dose region corresponding to its radiation hormesis theory. Further studies need to confirm the correlation between the radiation hormesis and the growth of the plants.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.19-28
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• 2014

Research was initiated in greenhouse to investigate effects of polymer, calcium, perlite and chitosan on the growth of Kentucky bluegrass (KB). A total of 24 treatment combinations were used in the study. Treatments were made of water-swelling polymer (WSP), calcium, perlite, and chitosan in soil organic amendment (SOA). Significant differences were observed in germination rate, turfgrass coverage, turfgrass density and top growth among treatments. Germination rate, density and plant height varied with time after seeding. A proper mix of WSP is considered to be lower than 3% for turfgrass coverage and density. Regarding survival capability and top growth, however, it was good under 6%. Overall KB growth was more influenced by calcium and perlite than chitosan. Calcium and perlite were the most effective elements for early survival capacity and turfgrass density, respectively. But no effect was found by chitosan. Top growth increased with three elements, being perlite > calcium > chitosan. The chitosan was effective in early germination, but there was no effect on top growth until 3 weeks, when compared with others. A further study is needed for investigating the effect of these materials on the growth characteristics in mixtures of sand and SOA before a field application.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.226-231
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• 2011

Ulmus davidiana var. japonica is a deciduous tree species used for traditional medicine. This study was conducted to investigate the variation of samara, seed, germination and growth characteristics among populations and among individuals within five natural populations of U. davidiana var. japonica distributed in Korea. The ten characteristics of samara and seed, the three germination behaviors as well as the two growth traits were studied in samaras collected from total 32 trees. Statistical analysis of all characteristics showed that there were significant differences among populations as well as among individuals within populations. In this study, the mean characteristics of this species were 13.0 mm in samara length, 9.7 mm in samara width, 1.37 in samara index, 0.015 g in samara weight, 3.07 mm in samara stalk length, 3.85 seed length, 2.66 mm in seed width, 1.46 in seed index, 1.29 mm seed thickness, 0.0062 g in seed weigh, 34.8% in germination percentage, 8.6 days in mean germination time, 3.5 ea./day in gemination rate, 37.7 cm in height and 4.90 mm in root collar diameter. Especially, coefficients of variations in samara weight, germination percentage, germination rate, height and root collar diameter were relatively high (${\geq}30.0%$) compared to other traits. There was no significant relationship between population association and geographical distribution. The results of principal component analysis for 15 characteristics showed that primary four principal components (PC's) explained 100% of the total variation. The first PC accounted for 41.8% of the variability which correlated with morphological traits, the second PC accounted for 32.9% of the variability which correlated with germination behaviors and the third PC accounted for 16.3% of the variability which correlated with growth traits.

• Journal of Korean Society of Forest Science
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• v.25 no.1
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• pp.80-84
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• 1975

The seeds, scions and plants of chestnut tree (Castanea. crenata) and Chinese chestnut tree (C. bungeana) were irradiated by gamma ray in order to know their biological effects on germination, plant growth and mutation at several accumulative doses and dose rates. The results of this study could be summarized as follows: 1. In general, the radio-sensitivity of scions was more sensitive to irradiation, showing 50% reduction dose of the control for grafting percentage at 3.1 kR as compared with 4.6 kR for the above reduction dose in germination rates of seeds. 2. The seeds treated by 5 kR dose resulted in some albino mutants at a rate of 0.84%. There was a general tendency that the seedling height reduced significantly as the irradiation dose increased. 3. The scions treated by an acute irradiation showed their 50% reduction dose in grafting at 3.2 kR for Chinese chestnut and at 3.1 kR for chestnut, respectively, while their irradiation doses increased three times, having 10.2 kR for the 50% reduction dose in the case of semi-acute irradiation. 4. When Chinese chestnut trees were irradiated during their dormant period with a total dose of 7.5 kR to 4.9 kR at a dose rate of 150 R to 98 R per day, there were induced giant leaf bud-sports at a frequency of 16.6%. The averag leaf area of the giant leaf bud-sports were measured at 96.36 square centimeters, while the area of normal leaf was only 26.28 square centimeters.