Identification method of ferritin absorption/activation ability of peanut (Arachis hypogaea L.) varieties under hydroponic condition.

In order to establish a rapid method to identify the absorption and activation ability of iron in different peanuts, the iron deficiency cultivars Nongda 818, Luhua 11, Shanhua 11, and the iron sensitive cultivars Luhua 12, ICG6848, and Baisha 1016 were employd in iron deficiency nutrient solution instead of soil. The yellowing time of new leaves in iron deficiency environment was recorded. After the new leaves of all peanut seedlings turned yellow, the iron supply was resumed. The seedlings were treated with 20 µmol/L FeSO₄ for 2 d and 4 d, 25 µmol/L FeSO4 for 2 d and 3 d, and 30 µmol/L FeSO₄ for 1 d, 2 d and 4 d, the increase of chlorophyll value (ΔSPAD), dry weight and iron uptake were measured to identify the iron uptake capacity. The iron activation ability of peanut was evaluated at 25 µmol/L Fe₂(SO₄)3 for 2 d and 4 d, 30 µmol/L Fe₂(SO₄)3 for 2 and 3 d, and 35 µmol/L Fe₂(SO₄)3 for 1 day, 2 d and 4 d. Results showed that the seedlings of all peanuts showed yellowing on the 10th day of iron deficiency treatment. Then, 25 µmol/L FeSO₄ was used to iron supply for 2 days, which led to in iron sensitive cultivars. When treated with 30 µmol/L Fe₂(SO₄)3 for 2 days, the increase of SPAD value and iron activation per plant were also significantly different between the deficient tolerant and sensitive cultivars. Therefore, considerting peanut iron absorption/activation ability, the increase of seedling SPAD, iron uptake per plant and/or activation per plant could be used as indicators after iron supply (25 µmol/L FeSO₄ or 30 µmol/L Fe₂(SO₄)3 for 2 days) when seedlings have been etiolated. [ABSTRACT FROM AUTHOR]