Influences of different iron levels on plant growth and photosynthesis of W. Murcottmandarin grafted on two rootstocks under high pH conditions

W. Murcott scion, budded onto two rootstocks, was evaluated under high pH conditions supplied with different Fe levels.Plant dry weight, leaf area, iron chlorosis symptom scale, leaf chlorophyll concentration, net photosynthetic rate, and ferric-chelatereductase (FCR) activity variables were investigated under high pH conditions. Control plants (T1) produced the most leaf area, whereasplants grown without Fe (T2) produced the least. Dry weight was highest in ‘Volkameriana’ T1 (control) plants and lowest in ‘Swinglecitrumelo’ T3 (10 ìM Fe and 7.8 pH) and T2 (0 ìM Fe and 7.8 pH) treatments. Significant differences in SPAD and iron chlorosis scalereading were found between rootstocks and treatments. Treatments significantly affected the net photosynthetic rate of the W. Murcottmandarin. Moreover, it was found that tolerant rootstock had higher FCR activity in application T2 than in applications T3 and T4 (100ìM Fe and 7.8 pH). The data of the present study suggested that scion budded onto Volkameriana rootstock showed a higher toleranceto iron deficiency than those budded onto Swingle citrumelo under high pH conditions