Optimization of tall fescue (Festuca arundinacea) callus induction and regeneration in culture medium containing ZnO and Ag nanoparticles

Abstract

This experiment was conducted to optimize in vitro regeneration of tall fescue (Festuca arundinacea) and study of ZnO and Ag nanoparticles effects on it. The effect of six combinations of growth regulators of auxin (2.4-D) and cytokinin (BAP and Kinetin) on stem and seeds halved explant (Iranian and Foreign) was evaluated in a completely randomized design with three replications. To investigate the effect of nanoparticles on callus induction and regeneration, four concentrations of silver nanoparticles (0, 20, 40, 60 mg l-1) and zinc oxide nanoparticles (0, 25, 50, 100 mg l-1) in a completely randomized design with three replications were performed. The reults showed that the halved seed micro-sample, the Iranian ecotype, and the MS/2 culture medium had the best results for this part of experiment. The culture medium containing 1 mg l-1 2.4-D and 0.1 mg l-1 kinetin was the most suitable culture medium for callus formation, number of days to callus formation, callus length and width, callus perimeter and area, fresh and dry weight of callus. Also, the culture medium containing 0.9 mg l-1 2.4-D and 0.5 mg l-1 BAP had a higher amount than other culture mediums in terms of indirect and direct regeneration. In rooting medium with the concentration of 0.25 mg l-1 NAA and 0.1 mg l-1 2.4-D, the maximum and minimum root length and days to rooting were observed, respectively. The analysis of variance showed that the effect of silver nanoparticles and zinc oxide nanoparticles on the number of days to callus induction was significant. The effects of silver nanoparticles on the percentage of regeneration also were significant. The results of mean comparisons of silver nanoparticles showed that in the concentration of 20 mg l-1 callus formation was induced more rapidly. However, the treatment of 60 mg l-1 had the lowest average of callus induction. The results of the mean comparison showed the positive effect of zinc oxide nanoparticles on concentration of 25, 50, and 100 mg l-1 on callus formation rate compared to the non-application of zinc oxide nanoparticles.