Effects of arbuscular mycorrhizal fungi on photosystem II activity of three pistachio rootstocks under salt stress as probed by the OJIP-test

Abstract

We applied chlorophyll a fluorescence as a biomarker to assess the growth response and PSII behavior and performance of three pistachio (Pistacia vera) rootstocks to different salt levels after inoculation with arbuscular mycorrhizal fungi Glomus mosseae and compared it with non-mycorrhizal plants (control). Our results confirmed the depressing effect of salt stress on mycorrhization extent and showed that the effect of salinity on colonization rate is completely under the influence of host plant. In this experiment, mycorrhizal symbiosis could enhance plants total dry mass (TDM), electron transfer on the donor and the acceptor side of PSII, decrease the energy dissipation and increase the comprehensive photosynthesis performance under salt stress as well as under normal conditions. We found that both donor and acceptor sides of PSII are the target sides under high salinity in pistachio rootstocks. We also found that performance index is the parameter that better reflects the responses of the studied rootstocks to progressive salt stress. Bane-baqi was less affected by salinity in terms of TDM followed by Sarakhs and Abareqi.