Effects of Salinity and Manganese on Physiological and Echophysiological Characteristics of Pistachio Seedlings (in Sand Culture)

In order to investigate the effect of Mn and salinity on some physiological and echophysiological characteristics of pistachio seedlings (cv. Badami-e-Zarand) in sand culture (perlite medium)، a factorial greenhouse experiment was carried out in the framework of a completely randomized design comprised of two factors namely: salinity (Zero، 75، 150، 225 and 300 mM NaCl) and Mn (Zero، 12، 24 and 36 µM MnSO4) in four replications. Results revealed that with an application of 150 mM of the salt، chlo a، chlo b as well as chlo a+b decreased by 12، 16 and 21% in comparison with control while Mn increased chlo a، chlo b as well as chlo a+b as compared with control. Carotenoids were observed to be significantly decreased through salt application but salinity×Mn interactions (at their different Mn levels، and salt application) did not significantly affect carotenoids. Although Superoxide Dismotaze (SOD) activity decreased in stage one (one week after application)، but it significantly increased (>30%) by application of 12 µM of Mn. SOD activity was assessed at the end of the experiment (8 weeks after salinity application). Results indicated that application of 30 mM of NaCl caused an increase of SOD activity، as a result of which the resistance of pistachio seedlings increased against salinity stress. An addition of Mn did not significantly affect the stress. Salinity treatment in each of the three experimental periods exerted a significant effect on Fv/Fm، and while salinity×Mn interaction did not significantly affect this parameter. Thus، it seemes to be finally concluded that Mn increase resistance against salinity in pistachio seedlings (cv. Badami-e-Zarand).