Afsaneh Shool and Mohammad Hossein Shamshiri
To study the interaction effect of arbuscular mycorrhizal fungi (AMF) Glomus mosseae and Pseudomonas fluorescens P52 strain bacteria, on chlorophyll fluorescence and photosynthetic pigments of pistachio seedling (Pistacia vera cv. Qazvini) under water stress, a greenhouse experiment was conducted using four levels of water stress (%100 field capacity (FC) as control and 75, 50 and 25% FC) and four levels of biofertilizer (plant without mycorrhizae and bacteria as control, mycorrhizae alone, bacteria alone and mycorrhizae and bacteria combination) in a completely randomized design as factorial with four replications. The minimum amount of maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm) was observed in water stress from 25% FC. The use of biofertilizer in water stress from 25% FC increased Fv/Fm. The minimum amount of Fv/Fm in water stress from 50% and 25% FC was observed in last time of measurement. The minimum amount of Fv/Fm in all levels of biofertilizer was related to last time of measurement. Water stress reduced chlorophyll (Chl) and carotenoids (Car) pigments content and the minimum amount of pigments in the combined treatment was observed in water stress from 25% FC. The results of this study showed that the pistachio plant is tolerance to water stress, because reduce in the efficiency of the photosynthetic apparatus occurred in water stress 25% FC and in last time of measurement.
