The effect of different concentrations of nano-graphene oxide and growth regulators on proliferation, development and maturation of asexual embryos

Background and Aim: In this study, based on the modified Hummers method, GO graphene oxide nanoparticles were prepared in different concentrations and tested on date calluses. The palm cultivar Majul, which originates from North Africa and is non-native to Iran, was used. In order to find a suitable growth regulator for the production of asexual embryos from embryonic calluses and embryonic maturation, different concentrations of graphene oxide nanoparticles in ۴ levels in a completely randomized design with ۳ replications in three factorial Factors were examined. At the end of every ۳ weeks, the number of embryos was evaluated. The studied treatments included ۵ concentrations of nano graphene ۰, ۵, ۱۵, ۲۵ and ۵۰ ppm, BAP treatment at two levels of ۰.۱ and ۰.۲ ppm and MS culture medium at two levels of full and half. The results showed that in all three stages of sampling, the number of embryos counted was affected by the three interactions of culture medium, nano graphene and BAP concentration. In the presence of small amounts of nanoparticles, the concentrations of MS and BAP can be considered lower. Due to the fact that the results of concentrations of ۵ and ۱۵ ppm nano graphene at a concentration of ۰.۱ BAP in the last step of counting did not differ significantly, lower concentrations can be used for greater efficiency and economic efficiency in the production of date embryogenic calli.Methods: In this study, date palm cultivar Majul, which is non-native to Iran and originates from North Africa, was used. In order to find a suitable growth regulator for the production of asexual embryos from embryonic calluses and embryonic maturation, their different concentrations were studied at ۴ levels in a completely randomized design with ۳ replications. . At the end of every ۳ weeks, the number of embryos was evaluated. The studied treatments included ۵ concentrations of nanographene which included ۰, ۵, ۱۵, ۲۵ and ۵۰ ppm and BAP treatments at two levels of ۰.۱ and ۰.۲ ppm and MS culture medium at two levels of full and half.First, MS medium was prepared, then ۳ g / l of activated charcoal was added to prevent phenolic secretions. The pH of the medium was adjusted to ۵.۶-۶.۵. Calluses were transferred to culture media with different hormonal treatments along with graphene oxide nanoparticles to be converted into embryogenic calluses and kept in these media for ۱۲ weeks and evaluated every ۴ weeks. SAS software (V ۹.۱) was used to analyze the data and LSD amon was used to compare the means and the graphs were drawn in Microsoft Office Excel ۲۰۱۰. Results: Based on the results, it was observed that in complete MS medium, ۵ ppm nanographene concentration and control treatment increased the number of embryos in all three stages by increasing BAP concentration, and ۵ ppm nanographene treatment produced more embryos than the control treatment. At other concentrations of nanographene, increasing the concentration of BAP decreased the number of embryos in all three stages of counting. The number of embryos in all three stages at both nano graphene concentrations (۵ and ۰ ppm) at ۰.۱ BAP was zero and no change was observed over time.In all three stages of counting in full MS medium, the highest number of embryos was obtained in the treatment of ۵ ppm nanographene and concentration of ۰.۲ BAP hormone, which in the second stage of counting ۱۸۷% and in the third stage ۵۲% increase compared to the previous stage was observed. Also, in the third counting step, it was observed that in the complete MS medium, the control treatment (zero nanographene concentration) was lower in both BAP concentrations than in the MS / ۲ medium. This may be due to the fact that in the MS / ۲ environment stress is applied to the callus due to a decrease in the concentration of macro and micro elements, resulting in an increase in the number of embryos produced.The results showed that when MS was halved at low concentrations of BAP (۰.۱ ppm) low concentrations of nanoparticles (۵ and ۱۵ ppm) had a better effect. In MS / ۲ medium, concentrations of ۲۵ and zero ppm (control treatment) increased the number of embryos by increasing the concentration of BAP hormone and treatment of ۲۵ ppm nanographene produced a larger number of embryos than the control treatment. In ۵ and ۱۵ ppm treatments, these results were reversed.. At ۵۰ ppm, no significant difference was observed between the two hormone concentrations. In the first and second stages of counting, the highest number of embryos was obtained at a concentration of ۲۵ ppm nano graphene and a concentration of ۰.۲ BAP hormone, but in the third stage, the highest number was observed at a concentration of ۱۵ ppm nanographene and a concentration of ۰.۱ BAP hormone (۳۳% increase compared to The second phase counted and increased by ۲۶۳% compared to the first phase) which was not significantly different from the treatment with ۵ ppm nanographene concentration and ۰.۱ BAP hormone concentration (۳۱% increase compared to the second phase and ۱۷۱% increase compared to the first phase).Conclusion: The results showed that in all three stages of sampling, the number of embryos counted was affected by the three interactions of culture medium, nanographene and BAP. In the presence of a small amount of nanoparticles, the concentrations of MS and BAP can be considered lower, and considering that the results of concentrations of ۵ and ۱۵ ppm nano graphene at a concentration of ۰.۱ BAP in the last counting step can not be significantly different, lower concentrations can be used for efficiency. Used more economically in the production of date embryonic calli.

Keywords:

Dates palm , Asexual embryogenesis , Graphene nanoparticles