Impact of cross-breeding of low phytic acid rice (Oryza sativa L.) mutants with commercial cultivars on the phytic acid contents

Phytic acid (PA) is considered as antinutrient in food and feed. Several low phytic acid (lpa) rice (Oryza sativa L.) mutants have been generated through induced mutation. Lpa mutant lines often exhibit inferior agronomic performance, and cross-breeding is applied to minimize these effects. The impact of such crossing steps on the PA contents in the resulting progenies is unknown. Therefore, three lpa rice mutants differing in mutation type were crossed with commercial rice cultivars, and PA contents in the progenies were determined for various generations grown at different locations. The PA contents of the lpa progenies were differently expressed for the investigated mutation-types and were dependent on environment and/or PA contents of the crossing parents. Nevertheless, for all three mutants, the homozygous lpa progenies always displayed significantly lower PA contents than the original wild-types subjected to the mutation. This demonstrated that cross-breeding of lpa rice mutants with commercial cultivars does not compromise the intended PA reduction and is a useful tool to obtain mutants stably expressing the intended lpa trait.