Variation in mineral elements in grains of 20 brown rice accessions in two environments.

Twenty rice accessions were planted in Hainan province, China, for 2 years to investigate the effects of genotype, environment, and their interactions on the Ca, Mg, Na, K, Fe, Zn, and Cu contents in brown rice. Analysis of variance showed that the Ca, Na and K were mainly affected by the genotypic variance, whereas the Fe, Zn and Cu were mainly affected by the environment variance. The genotype × environment interaction effects for Mg, Na, Zn, and Cu were highly significant (P < 0.001), though it only accounted for a small proportion of the total variation (0.5-16.3%). The correlation analyses showed that Mg was significantly positively correlated with K, Fe, and Zn. A total of 9 and 8 single nucleotide polymorphism (SNP) loci were identified in 2011 and 2012, respectively, which were strongly associated with for Ca, Cu, K, Na, and Zn.