LAUSR

Even though silicon is frequent compound in soil, its use in plant nutrient media is rare. Based on known physiological role and up to now performed studies it seems that silicon has a good potential to improve growth characteristics of in vitro cultivated plants. Before practical application, however, it is always necessary to assess the optimal conditions of application with regard to the fact that plant reactions to different chemicals added to nutritional media can vary on the species or even cultivar level. The presented study evaluate effects of potassium silicate used in in vitro cultivation media on growth parameters of Prunus persica × Prunus davidiana ‘Cadaman,‘ Prunus × amygdalopersica ‘GF 677‘ and Corylus avellana ‘Tonda di Giffoni‘ genotypes, which are frequently subject of commercial in vitro multiplication. In fact, four different concentrations of potassium silicate was added to the multiplication media, control medium was left silicon-free. Three different characteristics were observed during cultivation – number of new shoots per explant, weight of a new plant and length of new shoots, from which number of new shoots per explant was considered the most important factor. In all cases a positive effects of potassium silicate on the condition and other growth parameters of treated cultures were observed. In ‘Cadaman‘ culture significant growth changes appeared on media with 20 mg.l-1 potassium silicate, which can be recommended for future applications. For ‘GF 677‘ the best results were obtained on media with 2 mg.l-1 which can be recommended for improving condition and number of shoots on new plants. For hazelnut genotype ‘Tonda di Giffoni‘ best results were obtained on media with 10 mg.l-1 of potassium silicate, but also use of 5 mg.l-1 of potassium silicate significantly improved growth parameters. Generally, presented study provides important and practically useful insights into the practical use of silicon in cultivation media designated for commercial in vitro micropropagation.