Abstract
Genetic variability in micronutrient bioavailability, which is dictated by low grain phytic acid (PA)content, is limited in wheat varieties. The PA particularly enhances such a problem as it also relatedto an attendant loss of indigestible complexed nutrients and charged proteins in the waste and resultsin reduced their bioavailability in both humans and livestock. The new spring wheat mutant lines (M7generation) developed on the genetic background of cv. Eritrospermum-35 through gamma irradiationby 100 and 200 Gy using 60Co, were used for evaluation of grain PA content, the study of time germination on phytase activity (PhyA) and its organ-specific distribution. Our investigation showed the largegenotypic variation in PA content of the Eritrospermum-35 100 Gy- and 200 Gy-dosed mutant lines.The 23 mutant genotypes of which mostly 200 Gy-treated lines had signifcantly lower grain PA content by1.2- to 3.5-times than that parent, with its lowest mean of 0.78±0.02 mg g-1 in 100 Gy-dosed lines. Thevariation in PhyA of cv. Eritrospermum-35 and mutant lines was dependent on time germination (3 and6 hours) and doubling the germination time enhanced grain PhyA to 1.47-fold in cv. Eritrospermum-35,and to 1.36-3.53-fold in mutant lines, indicating that the effect of germination on PhyA was strongly timeand genotypes related. Organ-specific distribution (grain, roots, and shoots) of PhyA in cv. Eritrospermum-35 and 100 Gy- and 200 Gy-dosed mutant lines different by grain PA content, in 12- and 24-hoursseedlings showed a gradual decrease in grains enzyme activity while its level in roots and shoots of bothhours’ seedlings was the same. A mutant line numbered 35/1, had maximum PhyA in grains, roots, andshoots of 12-hour seedlings, which exceed the PhyA of cv. Eritrospermum-35 by 3.05-, 3.03- and 8.43-fold, respectively, which is valuable in developing spring wheat cultivars with high PhyA