The Effect of Some Disinfectants on the Contamination Control of Box Tree Explants under in Vitro Culture

Hyrcanian boxwood (Buxus hyrcana Pojark.) is an evergreen tree and native to the Hyrcanian forests in northern Iran, which is considred as one of the endangered plant species. In vitro propagation of this valuable species can prevent its extinction. The presence of fungal and bacterial contamination is one of the main challenges of in vitro culture of Buxus hyrcana, which can affect the propagation of this valuable species and on the other hand, can lead to many costs. In the present study, the efficacy of 15% Percidine, Aqua Percidine, Super Percidine and Percidine Plus in removing contamination from B. hyrcana explants was investigated under in vitro culture conditions compared to the usual method (using sodium hypochlorite).

The experiment was performed in factorial arrangement as a completely randomized design with 3 replications. First, for pre-treatment, explants (twigs and seeds) were washed with ordinary water and a few drops of dishwashing liquid for 5 minutes to remove surface contaminants. Then, they were placed in benomyl fungicide (1%) for 10 minutes. After washing, under laminar airflow, sterilization of explants was performed with experimental treatments. Experimental treatments included disinfectant (Percidine 15%, Percidine Aqua, Super Percidine, Percidine Plus (at concentrations of 0, 1, 2, and 4%) which were compared with sodium hypochlorite. After sterilization of the explants, the plant materials were placed on Murashige and Skoog medium. To measure contamination, cultures were examined under growth conditions at 25±1 °C with a light intensity of 1000 to 1500 lux (16 hours light and 8 hours dark).

The results showed that fungal and bacterial contamination in the seed explant was significantly reduced compared to the twig explant. On the other hand, Super Percidine sterilizer showed high efficiency (63%) in the twig explant in reducing contamination from culture medium. Moreover, in seed explants, in addition to Super Percidine, Aqua Percidine sterilizer also showed high efficiency in reducing contamination from seed surface (33%).

Therefore, it seems that the use of Super Percidine (2%) sterilizer can be useful for twig explants and both of Super Percidine (2%) and aqua Percidine (2%) is suitable for seed explants.