Response of dry beans to iron deficiency stress

Abstract

Two dry bean (Phasaolua vulgarla L.) cultivars, one susceptible (PI‐165078 (PI)) and one resistant (Great Northern Valley (GNV)) to Fe deficiency chlorosis in the field were grown in a modified Hoagland solution in a growth chamber under varying degrees of Fe stress (0.0, 0.05, 0.10, and 1.0 mg Fe/liter). Response to Fe‐deficiency stress was determined by measuring daily release of H ions and reductant from the roots, leaf chlorophyll and concentrations of Fe and Mn in leaves and roots. As the plants responded to Fe stress, both varieties released H ions and reductant from their roots, with GNV responding sooner than PI. There were generally no significant differences between cultivars in chlorophyll concentration. The Fe concentration in top leaves was not significantly different between cultivars at solution Fe levels below 1 mg/liter. There was some indication that GNV might be more Fe‐efficient at the 0.05 mg Fe/liter treatment than PI, but these two dry bean cultivars are similar enough in their response to Fe‐deficiency stress for both to be designated Fe‐efficient.

Key words:

• Chlorophyll
• Hoagland solution
• Leaf iron
• Leaf manganese
• pH
• Phaseolus vulgaria L
• Reductant
• Root iron
• Root manganese