Arbuscular mycorrhizal fungi and water stress on the physiology and quality of Parkia platycephalic benth

ABSTRACT Background: The water deficit characteristic of semi-arid regions can cause negative changes in plant physiology. Arbuscular mycorrhizal fungi can meet water needs by associating with plant roots, improving seedling quality. The physiological parameters and the quality of the seedlings of Parkia platycephala Benth. were evaluated as a result of the association of isolated strains of Gigaspora rosea, Gigaspora margarita, Acaulospora koskei, Acaulospora morrowiae, intercalated strains (a mixture of the four strains mentioned above) and a control (without inoculation) under two conditions of water regime (with and without stress). Results: Artificial inoculation of AMF is a promising management technique in the production of P. platycephala Benth seedlings for improving the physiological state, increasing seedling quality, and drought resilience. Under restriction water restriction conditions, the seedlings showed lower values of net CO2 assimilation, leaf transpiration, stomatal conductance, and higher values of internal CO2 concentration. Under these conditions, the G. rosea strain stood out with the lowest rate of net CO2 assimilation (A), leaf transpiration (E), and stomatal conductance (gs) with increases of 34, 49, and 70 %, respectively, compared to the control. Conclusion: Stomatal closure is a strategy used by Parkia platycephala Benth. seedlings to prevent excessive water loss, and the Gigaspora rosea strain is responsible for mediating the best physiological conditions and better quality seedlings.