Grain phytic acid content in japonica rice as affected by cultivar and environment and its relation to protein content

Phytic acid and protein contents in grains of japonica rice cultivars collected from different areas of China were assayed in this study. Meanwhile, a multi-location trial was conducted to determine phytic acid content of 24 cultivars grown at 4 locations with wide differences in ecological conditions. For 72 cultivars, phytic acid content ranged from 0.685% for Xiu217 to 1.03% for Huai9746, with a mean of 0.873%, and protein content ranged from 6.45% for Xiu52 to 11.1% for K45, with a mean of 8.26%. There was no significant correlation between grain phytic acid and protein content, suggesting the possibility of breeding japonica rice cultivars with low phytic acid and high protein contents. The effects of cultivars, environments (locations) and their interactions on phytic acid content were all highly significant, with the location having the largest effect. The highly significant interaction between cultivar and environment suggests that the correct evaluation of rice germplasm by phytic acid content should be conducted in multi-environments.