Genotype and environment effects on rice (Oryza sativa L.) grain arsenic concentration in Bangladesh

Genetic analysis of 38 rice varieties released by the Bangladesh Rice Research Institute (BRRI) identified 34 as indica, 2 as admixed between indica and aus, and 4 as belonging to the aromatic/Group V subpopulation. Indica varieties developed for the two genotype-environment interaction (GEI) on grain arsenic (As) concentration when these rice varieties were grown at ten BRRI research stations located across diverse agro-ecological zones in Bangladesh. G, E and GEI, significantly influenced grain As concentration in both seasons. Overall, E accounted for 69%–80%, G 9%–10% and GEI 10%–21% of the observed variability in grain As. One site, Satkhira had the highest mean grain As concentration and the largest interaction principle component analysis (IPCA) scores in both seasons, indicating maximum interaction with genotypes. Site effects were more pronounced in the boro than in the aman season. The soil level of poorly crystalline Fe-oxide (AOFe), the ratio of AOFe to associated As, soil phosphate extractable As and soil pH were important sub-components of E controlling rice grain As concentration. Irrespective of environment, the mean grain As concentration was significantly higher in the boro (0.290 mg As kg-1) than in the aman (0.154 mg As kg-1) season (p