The Effect of Mycorrhizal Fungal Strains on the Concentrations of Phosphorus and Selected Micronutrients in Tomato Fruit (Lycopersicon esculentum Mill.)

The research hypothesis postulates that mycorrhizal fungal strains can increase the content of phosphorus (P) and selected micronutrients in tomato fruit. The aim of this study was to determine the suitability of three tomato cultivars for growing in a heated plastic tunnel, and to evaluate the influence of fungal strains applied to the rhizosphere of tomato plants on the concentrations of selected minerals, in particular P, iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn), in the fruit. A two-factorial experiment was conducted in 2015-2016. Tomatoes were grown in coco coir in a heated plastic tunnel in the Experimental Garden of the University of Warmia and Mazury in Olsztyn. The first experimental factor were three tomato cultivars, 'Growdena F-1', 'Listell F-1' and 'Torero F-1', suitable for growing in a controlled environment. The second experimental factor was growing tomatoes in coco coir mats with and without fungal strains: control treatment (without fungal strains), growth medium inoculated with fungi of the genus Glomus, growth medium inoculated with a combination of fungi of the genus Trichoderma. The experiment had a s split-block design, with 10 plants per replicate in each treatment. In order to determine the mineral content of tomato fruit, plant material was dried at a temperature of 65 degrees C and ground in an electric mill. The samples were analyzed in the Chemical and Agricultural Research Laboratory in Olsztyn to determine their content of P, Fe, Cu, Mn and Zn. The analyzed fungal strains did contribute to a significant increase in P concentrations in tomato fruit, compared with the control treatment. Fungi of the genera Glomus and Trichoderma ssp. increased the Fe content of tomato fruit by 12.5% and 16.9%, respectively, compared with the control treatment, and Glomus fungi increased also Mn concentration in tomato fruit.