Effect of iron stress on metabolism and seed quality of pea

Pea (Pisum sativum L.) var. Azad was grown in refined sand at graded levels of Fe ranging from acute deficiency (0.28 mg/litre) to excess (28.0 mg/litre). Low (< 5.6 mg/litre) Fe produced visible symptoms of deficiency 30 days after sowing on young leaflets and tendrils. Biomass, economic yield, chlorophyll content, hill reaction activity and activity of catalase and peroxidase decreased by low (< 5.6 mg/litre) as well as excess (> 5.6 mg/litre) Fe. The concentration of Fe in leaflets and seeds increased with an increase in Fe supply. In acutely Fe deficient (0.28 mg/litre), no seeds were produced as the pods were empty. Deficiency of Fe decreased the seed weight and quality more than that of excess. The decrease in concentration of starch and proteins and increase in phenols and nitrate nitrogen in pea seeds were less pronounced in excess than deficiency of Fe. In seeds, sugar content was lowered by deficient Fe and increased by that of excess.