M.A. Thesis:

effect of multi walled carbon nanotubes on in vitro callus induction and plant regeneration in withania coagulans

In order to investigate the effect of multi walled carbon nanotubes on in vitro callus induction and plant regeneration in Withania coagulans, two separated experiments were conducted as factorial and in a completely randomized design in Azad university of Sabzevar. At first the effect of various hormonal compounds and the consumption of multi walled carbon nanotubes were investigated. The experimental factors contains hormonal compound of medium in four levels that are 0.5 mg/lit of 2,4-D , 1 mg/lit of 2,4-D , 0.5 mg/lit of 2,4-D plus 0.5 mg/lit of BAP and 1mg/lit of 2,4-D plus 0.5 mg/lit of BAP. The concentrations of multi walled carbon nanotube were in three levels of 0, 10 and 50 µg/ml. After choosing the best hormonal compound for callus induction, the effect of BAP concentration in three levels of 0.5, 1 and 1.5 mg/l and the application of carbon nanotubes in three levels of 0, 10 and 50 µg/ml on shoot regeneration was studied. The results showed that the concentration of carbon nanotubes has a meaningful effect on callus induction percent, callus diameter and callus fresh weight. The application of 10 µg/ml carbon nanotubes increased the diameter and fresh weight of callus, but it didn’t have any significant effect on callus induction .The concentration of 50 µg/ml of carbon nanotubes decreased the overall properties of callus induction. The hormonal compound didn’t affect the callus induction percent, but it had significant effect on diameter and fresh weight of callus. Application of 0.5 mg/l BAP decreased the callus diameter and increased the callus fresh weight. The highest callus diameter and fresh weight were obtained in medium containing 0.5 mg/l 2,4-D and 0.5 mg/l 2,4-D plus 0.5 mg/l BAP, respectively. Increasing the concentration of 2,4-D to 1 mg/l , decreased the callus diameter and fresh weight. The effect of carbon nanotubes and BAP concentration were significant on in vitro shoot regeneration characteristics of withania coagulans. The application of carbon nanotubes in medium significantly decreased the regeneration percentage of shoots and their numbers. In medium containing 50 µg/ml of carbon nanotube, no regeneration of shoots were obtained. The increasing BAP concentration to 1 mg/l increased the percentage of shoot regeneration, but the application of 1.5 mg/l of BAP decreased it. The highest number of shoots in callus was obtained in 0.5 mg/l BAP and upper concentration of BAP significantly decreasedthe number of shoots.

Keywords: withania coagulans, Callus, Regeneration, Carbon nanotubes, Citokinin