GRAIN PHYTIC ACID AND PROTEIN ARE HIGHLY CORRELATED IN WINTER-WHEAT

Phytic acid (myo-inositol hexakisphosphate), the major storage form of P in seeds, is believed to have a negative impact on nutritional quality. Since breeding for low phytic acid has been proposed for several cereals and legumes, it is important to predict the effects of selection against phytic acid on other major grain components. Experiments were conducted to determine the quantitative relationship between grain phytic acid P, total P, and protein in two winter wheat (Triticum aestivum L.) populations, each consisting of F6 progeny of a double cross. Substantial variation in phytic acid P was observed, with the range in values equal to 30 and 48% of the respective population mean. Observed variation in phytic acid P was highly and positively correlated with variation in grain total P (r = 0.93 and 0.96 in Populations 1 and 2, respectively), and with variation in grain protein (r = 0.65 and 0.87, respectively). The close correlation of phytic acid P with both total P and protein indicates that selection against grain phytic acid would lead to undesirable reductions in both grain total P and protein.