effects of multi-wall carbon nano tube (mwcnt) on nepeta cataria and salvia sclarea in vitro culture

Nepeta cataria l. and salvia sclarea l. are two species of lamiacea family and endangered species in yazd province of iran. for this the reason we studied callus induction and shoot regeneration of these species and mwcnts effects on them to improve the proliferation rate. in order to callus formation ms medium supplemented with 0.1mg l^-1 kin and 1 mg l^-1 naa were used. for shoot regeneration, ms containing 0.1 mg l^-1 iaa and 1 mg l^-1 ba were applied. concentrations of carbon nanotubes at 0, 20, 60, 80 and 200 µg ml^-1 mwcnts in regeneration and callus induction media were used in both species. the results showed significant differences between using mwcnts and control in callus induction and shoot regeneration rate. the most callus mass of n. cataria with 20 µg ml^-1 was 304 mm³ whereas controls was 117.75 mm³. the highest callus mass of s. sclarea with 80 µg ml^-1 mwcnts was 414 mm³, but in controls was 182.15 mm³. using of 20 µg ml^-1 mwcnts with 6.17 shoots per explants was the best shoot regeneration in n. catari and treatment by 80 µg ml^-1 mwcnts had the lowest regeneration rate. using concentration of 80µg ml^-1 mwcnts with 4.2 shoots per explants led to maximum proliferation and the least regeneration was 1.85 shoots in 200 µg ml^-1 mwcnts treatment of s. sclarea. it seems that the effect of mwcnts on propagation may be dose dependent, high concentrations of nanotubes reduce callus formation and shoot regeneration in these plants.