Evaluation and Identification of Wheat-Aegilops Addition Lines Controlling High Grain Iron and Zinc Concentration and Mugineic Acid Production

Iron and zinc deficiency affects more than half of the world population due to low inherent micronutrient content of cereals and other staple foods. The micronutrient deficiency is further aggravated by poor availability of these minerals in calcareous soils and their uptake by crop plants. Series of available wheat-Aegilops addition lines were evaluated for identification of alien chromosomes carrying genes for high grain iron and zinc concentrations and release of mugineic acid(s) facilitating micronutrient uptake under their deficient conditions. Addition lines of chromosome 2S(v), 2U(v) and 7U(v) of Ae. peregrina, 2S(1) and 7S(1) of Ae. longissima and 2U of Ae. umbellulata were found to carry genes for high grain iron whereas the group 7 chromosomes had genes for higher grain zinc. Higher release of mugineic acid (MA) under iron deficient condition was observed in addition lines of chromosome 2S(v), 2U(v), 4U(v) and 7S(v) of Ae. peregrina, 2S(1) and 6S(1) of Ae. longissima and 2U and 5U of Ae. umbellulata. Higher grain and root iron concentration and MA(s) release under iron sufficient condition in the group 2 chromosome addition lines suggests that their high grain iron may be attributed to the higher uptake of the micronutrients through MA(s). These addition lines with two- to threefold high grain iron and zinc concentration could be used for precise introgression of genes into elite wheat cultivars for enhanced uptake of these micronutrients by wheat plants in problematic soils and their biofortification in grains.