Root-reducing capacity, rhizosphere acidification, peroxidase and catalase activities and nutrient levels of Citrus taiwanica and C-volkameriana seedlings, under Fe deprivation conditions

摘要

The Fe deficiency created by either deprivation of Fe, low Fe supply or addition of CaCO3/NaHCO3 to Hoagland nutrient solution resulted in significant changes of the physiological and biochemical parameters of the rootstocks C. taiwanica and C. volkameriana. For instance, the lack of Fe and low Fe supply of 3 muM Fe-EDDHA induced an increase in the Fe root-reducing capacity and rhizosphere acidification. Seedlings treated with adequate Fe (20 muM Fe-EDDHA) showed a decline in the Fe- reducing capacity and in rhizosphere acidification. Fe deficiency was associated with a significant decline in peroxidase and catalase activities. Fe deprivation conditions increased the concentration of N, P, Ca, Mg and Mn and reduced the concentration of Fe and Zn in young leaves of both rootstocks. C. volkameriana was found to be more sensitive to Fe chlorosis than C. taiwanica.