Iron Accumulation, Root Peroxidase Activity, and Varietal Interactions in Soybean Genotypes That Differ in Iron Nutrition

Abstract

Four soybean genotypes (Glycine max L. Merrill) differing in their ability to accumulate iron were studied: the efficient genotypes Hawkeye (HA) and A62-9 (E-9) and the inefficient genotypes PI-54619-5-1 (PI) and A62-10 (I-10).The distribution of iron in the tissues of plants grown in a growth chamber in nutrient solutions containing various levels of iron was determined. A greater amount of iron was associated with the roots of inefficient plants than with roots of efficient plants, indicating a slower rate of iron translocation in the former. After determination of the amount of iron in the shoots at low levels of nutrient iron, the ability of the several genotypes to accumulate iron was rated HA> E-9> I-10>/= PI. At the highest level of nutrient iron the rated efficiencies were E-9> HA> I-10> PI. Accumulation of iron in the primary leaves provided an excellent indication of whole-plant iron accumulation. A reduction in accumulation of iron by efficient plants occurred when the plants were grown together in the same solution as inefficient ones.