Variability of sorghum genotypes to tolerate iron deficiency

Sorghum [Sorghum bicolor (L.) Moench] needs to be improved for its ability to tolerate and produce under iron (Fe) deficiency conditions. To do this, sorghum germ plasm from various sources were screened and identified for performance under Fe deficiency conditions. Twenty‐nine inbred lines and 41 experimental lines used by sorghum breeders at the Nebraska Agricultural Experiment Station, 31 inbred lines used in a disease and insect nursery at the Texas Agricultural Experiment Station, 10 genotypes from Nigeria, and 78 S1 progenies from the Nebraska population NP20BR were screened to determine germ plasm differences under Fe deficiency conditions. Iron deficiency was induced in plants by growing them in a growth chamber in nutrient solutions with nitrate as a source of nitrogen. Observations on the rapidity with which plants became Fe deficient were recorded. Genotypes that remained green and tolerated Fe deficiency conditions for longer periods of time were QL3 (Texas), SC630–11E, SC33–9–8‐E4, and Plainsman inbreds; 80–4124, 80–3431, 80–3464, and 80–3716 experimental lines; and KANO L.I from Nigeria. The genotypes that became Fe deficient more rapidly and did not tolerate low Fe were SC118–15E, SC369–3–1JB, Redlan, TX2775, TAM428, and KS56 inbreds; 80–3653, 80–3707, and 80–3782 experimental lines; and FFB L and C 7.4 from Nigeria. Seedlings from S progenies of the NP20BR population showed fairly broad differences to Fe deficiency, but differences were not as great as those noted for inbred lines. Sufficient diversity among sorghum inbred lines and S‐± progenies of the population occurred to suggest that progress in improvement of sorghum for Fe deficient should be feasible.