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

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.