Morphological and Biochemical Responses of Gerbera (Gerbera Jamesonii L.) to Application of Silica Nanoparticles and Calcium Chelate under Hydroponic State

The purpose of this study was to investigate the response of physicochemical properties of gerbera (Gerbera Jamesonii L.) to silica nanoparticles (Nanoparticle-SiO2) and calcium chelate (Ca-Chelate) in nutrient solutions. A factorial experiment based on completely randomized design with two factors was conducted in four replicates. The first factor the concentration of Nanoparticle-SiO2 in nutrient solutions with four levels (0, 20, 40, 80 mg L-1), and the second factor was the concentration of Ca-Chelate in the nutrient solution with four levels (0, 60, 120 and 240 mg L-1). Flower diameter, peduncle length, leaf area, fresh and dry weights of root, leaf and flower, stem bending, leaf ionic leakage, chlorophyllindex, maximum efficiency of Photosystem II (Fv/Fm), percentages of cellulose, hemicellulose, and holocellulose in stem, and phenylalanine ammonia-lyase activity in leaves were measured. According to the results, in comparison to the control, application of 240 mg L-1 Ca-Chelate together with 80 mg L-1 Nanoparticle-SiO2, resulted in 1.5 times less stem bending and decreased leaf ionic leakage by 28%. The highest activity of phenylalanine ammonia-lyase in leaves was observed in the treatment with 60 mg L-1 Ca-Chelate (2.91 unit mg fresh leaves-1). The best treatment in terms of the chlorophyllindex, leaf area, percentages of cellulose and the maximum efficiency of Photosystem II (Fv/Fm) was the treatment with 120 mg L-1 Ca-Chelate and 80 mg L-1 Nanoparticle-SiO2. Therefore, application of 40 mg L-1 Nanoparticle-SiO2 and 60 mg L-1 Ca-Chelate in the hydroponic nutrition solution can be suggested for gerbera plants.