Differential response of two soybean genotypes to zinc induced iron deficiency chlorosis

Abstract

A greenhouse experiment using nutrient solutions was conducted to study the influence of zinc on the growth and composition of an Fe-efficient (Hawkeye) and an Fe-inefficient (PI-54619-5-1) soybean genotypes at various levels of Fe. Three levels of zinc (0.1,1.0 and 5.0 mg/l) in combination with three levels of Fe (0.1, 1.0 and 5.0 mg/l) were used. In general, increased zinc levels resulted in a growth reduction in both genotypes with the Fe-inefficient plants being more sensitive to Zn level. Increased Zn resulted in a decrease in Fe uptake and trans-port from the roots to the plant tops. The reduction in Fe transport may be greater than the reduction in uptake and resulted in an accumulation of Fe in the roots. The Fe-efficient genotype had a higher Fe con-tent than the Fe-inefficient at corresponding treatment levels. Increasing Fe level offset the adverse effect of Zn on the growth and Fe uptake in both genotypes.