Arbuscular mycorrhizal fungi on the initial growth and nutrition of Parkia platycephala Benth. under water stress

Abstract

Parkia platycephala Benth. (Fava-de-bolota) found in areas of Cerrado-Caatinga transition, is a species with potential for feeding ruminants in arid regions. The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizal fungi (AMF) on the initial growth and nutrition of P. platycephala Benth. seedlings under water stress. The experimental design was a randomized block design in a 2 × 6 factorial scheme with five replications, consisting of two water regime conditions (with and without stress), four AMF strains (Gigaspora rosea, Gigaspora margarita, Acaulospora koskei, and Acaulospora morrowiae), one treatment with associated inoculum (Mix), and one control. At 120 days after sowing, the morphological variables height (H), stem diameter (SD), number of leaves (NL), root length (RL), total root volume (TRV), shoot dry mass (SDM), root dry mass (SDM) and total dry mass (TDM) were evaluated. Nutrient contents and mycorrhizal colonization rate were also evaluated. The variables NL, SDM and TDM presented significant interaction between inoculation with the fungi and the studied water conditions. For the contents of P, Mg and Mn there was also interaction, being the best results with the strains A. koskei, Mix, A. morrowiae and control, respectively, in the condition without water stress. Mycorrhizal fungi favored plant growth as well as the absorption of P, Mg, Mn and Zn.