Arsenic Accumulation in Rice ( Oryza sativa L . ) Varieties of 1 Bangladesh : A Glass House Study

26 A glass house study was conducted to investigate the accumulation of arsenic in tissues of five 27 widely cultivated rice (Oryza sativa L.) varieties of Bangladesh namely BRRI dhan 28, BRRI dhan 28 29, BRRI dhan 35, BRRI dhan 36, BRRI hybrid dhan 1. Arsenic concentrations were measured in 29 straw, husk and brown and polish rice grain to see the differential accumulation of arsenic among the 30 rice varieties. The results showed that the concentrations of arsenic in different parts of all rice 31 varieties increased significantly (p < 0.05) with the increase of its concentrations in soil. The rice 32 varieties did not showed significant differences in arsenic accumulation in straw, husk, brown and 33 polish grain when the concentrations of arsenic in soil was low. However, at higher concentrations of 34 arsenic in soil, different rice varieties showed significant differences in the accumulations of arsenic 35 in straw, husk and grain. Significantly higher concentrations of arsenic in straw and husk of rice were 36 observed in BRRI hybrid dhan 1 compared to those of other verities. The BRRI dhan 28 and 35 37 concentrated significantly higher amount of arsenic in brown and polish rice grain compared to those 38 of other rice varieties. The results imply that arsenic translocation from root to shoot (straw) and 39 husk was higher in hybrid variety compared to those of non-hybrid varieties. Arsenic concentrations 40 in brown and polish rice grain of five rice varieties were found to follow the trend: BRRI dhan 28 > 41 BRRI dhan 35 > BRRI dhan 36 > BRRI dhan 29 > BRRI hybrid dhan 1. The order of arsenic 42 contents in tissues of rice was: straw > husk > brown rice grain > polish rice grain. 43