Abstract

To assay the efficiency of graphite nanoparticles (GtNPs) in sterilizing tissues and their role in enhancing genetic diversity, sweet potato is considered an important crop; hence its explants were used. In this experiment, GtNPs of 200, 400 and 800 ppm concentrations were used for sterilization of MS callus induction and regeneration media in Abees cultivar. The results showed that GtNPs had a good potential for removing bacterial contaminants without having side effects on the explant viability during the sterilization of sweet potato tissue in all their concentrations. Also, the percentage of callus induction increased from 98.67% in control to 100% in all GtNPs concentrations. The number of shoots per callus was enhanced at 400 ppm concentration. RAPD molecular markers and SDS-PAGE analysis were used to assess the genetic diversity of the sweet potato selected plants obtained from somaclonal variations in combination with GtNPs. Five decamer random amplified polymorphic DNA (RAPD) primers generated a total of 96 DNA fragments from the selected variants and their parent. Out of them, 82 polymorphic bands appeared with 85.42% polymorphism. The levels of DNA and protein patterns polymorphism within each treatment varied. RAPD and protein markers revealed that the concentration of 800 ppm showed the lowest similarity average among the ten selected variants and their parent. The obtained results indicated that somaclonal variation with GtNPs can be combined to increase the induced mutations frequency.

Key words: Graphite nanoparticles, somaclonal variation, random amplified polymorphic DNA (RAPD), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).