Effects of priming with multi-walled carbon nanotubes on seed physiological characteristics of Hopbush (DodonaeaviscosaL.) under drought stress

This paper reports the effects of different dosages of multi-walled carbon nanotubes (MWCNTs) on seed germination of hopbush, a medicinal multipurpose plant. After nano-priming and drying under room temperature, the seeds were placed in a germinator under 20 °C constant temperature and 65% relative humidity with a photoperiodic regime of 16 h light/8 h dark at 1000 lux fluorescent light. The results show that MWCNTs can dramatically improve seed germination percentage, mean germination time (MGT), root and stem lengths, as well as fresh and dry weights of root and stem. When no drought stress was applied, germination percentage of 10 and 200 mg/l nano carbon treatments was found to be 100%, and MGT in all the studied treatments had a marked decrease as compared to that of the control counterparts. The best results were gained at zero osmotic pressure, in which the effect of CNTs treatment on the mentioned traits was maximal at 30 mg/l. Increasing the level of drought stress revealed that 50 and 100 mg/l dosages of MWCNTs could more favourably affect both the hopbush growth parameters and seed germination. Therefore, nano-priming with carbon tubes can be recommended for enhancing seed germination and plant growth in work on afforestation with hopbush, an evergreen shrub suitable for desert conditions.