Comparison of physiological responses of peach and almond seedlings to iron deficiency

Responses of young seedlings (15 to 45 days old) of bitter almond (Prunus amygdalus Batsch) and of a variety of peach (Prunus persica [L.] Batsch, var. Elberta) to either absolute iron deficiency (2 muM Fe in the culture medium) or bicarbonate induced iron deficiency (culture medium containing 30 muM Fe and 10 mM NaHCO3) were studied. The culture was conducted on nutrient solution in a growth chamber with controlled conditions. Iron deficiency, especially the one induced by bicarbonate, stimulated root growth; this stimulation was more pronounced in almond seedlings. The concentration of total iron in green leaves was not significantly different from that of chlorotic ones, but the concentration of ferrous iron was much lower in chlorotic than in green leaves. Regardless of the cause of iron deficiency, iron transport was severely inhibited. This inhibition was more pronounced in peach than in almond seedlings. Root capacities (per plant) of acidification and iron reduction were greater in almond than in peach seedlings. Bicarbonate greatly inhibits iron reduction in the two plant species.