Analysis of the effects of Glomus etunicatum fungi and Pseudomonas fluorescence bacteria symbiosis on some morphological and physiological characteristics of Mexican lime (Citrus aurantifolia L.) under drought stress conditions

To analyze the effects of Glomus etunicatum fungi and Pseudomonas fluorescence bacteria on some morphological and physiological characteristics of Mexican lime plant under drought stress conditions, a factorial experiment was conducted. This experiment was based on a completely randomized design with three replicates; each replicate was composed of two pots. The factors used consisted of G. etunicatum fungi and control, Pseudomonas fluorescence bacteria and control, and drought stress at three levels (−0.35, −0.47, and −0.6 bars). The analyzed characteristics were leaf chlorophyll content, leaf temperature, rate of net photosynthesis, transpiration, leaf relative water content (RWC), and percentage of root colonization. Data analysis revealed that both fungi and bacteria increased leaf chlorophyll content, net photosynthesis rate, transpiration, and leaf RWC. Moreover, the presence of fungi reduced leaf temperature while inoculation of bacteria had no effects on that the parameter. In addition, with the increase of irrigation periods, leaf temperature and transpiration were also increased. Results showed that root colonization percentage dropped with increased irrigation and the highest root colonization percentage was observed in simultaneous inoculations of fungi and bacteria with a two-day irrigation period.