Efficacy of Pseudomonas strains on moderate drought stress on growth and physiological characteristics of pistachio cultivars

Using plant probiotic bacteria, which can induce systemic tolerance in plants, is one of the most important strategy to reduce the damage of drought stress in plants. In this study the effect of four fluorescent strains (T17-4, VUPF5, 428, CHA0) was investigated on resistance of two pistachio cultivars (Badami-Rize-Zarand and Sarakhs) against the drought stress. A completely randomized design was applied with a factorial arrangement at three replications in a greenhouse trial. In order to evaluate the effects of bacteria on reduction the effects of drought stress, some parameters such as prolin, soluble sugars, chlorophyll a, chlorophyll b, P, Zn, Fe content of shoot and root were measured. The results showed that drought stress increased the prolin and soluble sugars content in both inoculated and non-inoculated seedlings, although the content of prolin and soluble sugars in inoculated seedlings were higher than non-inoculated seedlings. The result also indicated that the drought stress reduces growth parameters, photosynthesis pigments and mineral element content in both cultivars under inoculated and non-inoculated conditions. The most reduction of these traits were recorded in non-inoculated seedlings. The cultivars of pistachio showed different responses to drought stress, so that sarakhs cultivar was recognized more sensitive to drought stress than badami-Rize-zarand cultivar.