• Journal of Radiation Protection and Research
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• v.17 no.1
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• pp.21-30
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• 1992

The frequencies of KCCH cyclotron neutron (30 cGy/min) or $^{60}Co\;{\gamma}-rays$ (210 cGy/min)-induced asymmetrical interchanges (dicentrics and centric rings) and acentric fragments (deletion) at several doses were measured in the normal human peripheral blood lymphocytes Chromosome aberrations were scored at the first nitosis after stimulation with phytohemagglutinin. The neutron and y-ray data were analysed on linear, power-law, quadratic and linear-quadratic model . When the dicentrics and centric rings of ${\gamma}-rays$ datas were pooled and fitted to these model, good fits were obtained to power-law $[Y=(5.81{\pm}1.96){\times}10^6D^{1.93+0.06},\; P=0.931]$, quadratic $[Y=(3.91{\pm}0.09){\times}10^{-6}D^2,\;P=0.972]$ an linear-Quadrati model $[Y=(6.55{\pm}6.83){\times}10^{-5}D+(3.72{\pm}0.22){\times}10^{-6}D^2\; P=0.922]$, except for linear model (P=0.067) As in the case of neutron data, the best fit was obtained to the linear model $(Y=(6.12{\pm}0.17){\times}10^{-3}\;D-0.22,\;P=0.987]$ and good fits were obtained to power-law$[Y=(5.36{\pm}3.02) {\times}10^{-4}D^{1.42+0.11},\; P=0.601]$ and linear-quadratic model$[Y=(2.43{\pm}0.70){\times}10^{-3}D+(1.21{\pm}0.39){\times}10^{-7}D^2$, \;P=0.415], except for quadratic model (P<0.005). The relative biological effectiveness (RBE) of neutron compared with y-ray was estimated by best fitting model. In the asymmetrical interchanges range between 0.1 and 1.5 per cell, the RBE was found to be $2.714{\pm}0.408$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.9-16
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• 2022

Rice is one of the most important staple foods in Wnju, Jeonbuk, South Korea. However, rice consumption has dramatically decreased as eating habits have diversified owing to rapid economic growth. Recently, floury endosperm rice varieties have been developed to invigorate the rice processing industry, because dry-milled rice flour is economically and environmentally suitable for massive rice flour distribution. The National Institute of Crop Science has developed 'AromaT', an early-maturing black rice with floury-endosperm, suitable for tea and dry milling. 'AromaT' was derived from a cross between 'Suweon542' as the floury endosperm source and 'Heugjinju' as the black and aromatic source. In this study, 'AromaT' and its parents, 'Suweon542' and 'Heugjinju', were analyzed for agronomic traits, anthocyanin content, and their major physicochemical properties by different planting date. The field experiment was conducted in Wanju, Jeollabuk-do Province, South Korea, in 2019. The transplanting dates were May 30 (ordinary season), June 25 (double-cropping season), and July 10 (late season). The yield performance of brown rice 'AromaT' was 330 kg/10 a in the double-cropping cultivation method and was the highest among the transplanting dates. The floury endosperm of 'AromaT' was derived from 'Suweon542' containing 'flo7', located on chromosome 5 and known to control floury endosperm. With the late planting date, the anthocyanin content of 'AromaT' was 570.5 mg/100 g, much higher than that of 'Heugjinju' (376.3 mg/100 mg). The brown rice of 'AromaT' also exhibited the pop-corn-flavoring 2-acetyl-1-pyrroline, exclusively detected in aroma rice varieties. The average particle sizes of 'AromaT' and 'Suweon542' were 67.12 ㎛ and 70.9 ㎛, respectively, lower than that of 'Heugjinju' (95.5 ㎛) with a black transparent endosperm. The average damaged starch content of 'AromaT' was 8.1%, lower than that of 'Heugjinju' (10.05%) and Suweon542 (9.5%). As a result, 'AromaT' with high anthocyanin content, fine particle size, and low damaged starch content is expected to provide a new rice material in various processing fields.