An Investigation of Inorganic Arsenic Concentration in Whole Rice Grains and Ratio of Perfect Grain in ‘Koshihikari’

High temperatures lead to higher concentrations of inorganic arsenic in the rice grain; thus, locations with high levels of inorganic arsenic concentrations in rice grains will likely increase with global warming. Therefore, it is important to develop rice cultivars with lower inorganic arsenic concentrations in grains. Here, we investigated inorganic arsenic concentrations in whole rice grains and ratios of perfect grains using reciprocal chromosome segment substitution lines (CSSLs) and near-isogenic lines (NILs) derived from the crossing between a japonica cultivar ‘Koshihikari’ and an indica cultivar ‘Takanari’ which has a lower concentration of inorganic arsenic in grain than that in ‘Koshihikari’. A NIL showing a lower inorganic arsenic concentration in grain than that in ‘Koshihikari’ was identified as that carrying a ‘Takanari’ chromosome 10 segment in a ‘Koshihikari’ genetic background. There was no significant difference in the ratio of perfect grain between the NIL and ‘Koshihikari’.