Effect of in vitro shoot multiplication and somatic embryogenesis on 5-methylcytosine content in DNA of Myrtus communis L.

Reversed-phase HPLC analysis of 2'-deoxynucleosides was performed to study the amount of 5-methylcytosine in genornic DNA of Myrtus communis L. About 11% cytosines were found to be methylated in DNA of field growing shoots. This amount showed no variation after the establishment of shoots in vitro or their subsequent rooting and acclimatisation to ex vitro conditions. Therefore, adult elite plants can be micropropagated and transferred to the field without global DNA methylation changes. Likewise, no trend in 5-methylcytosine content was introduced by increasing the number of subcultures in either adult- or seedling-originated shoot stocks. On the other hand, no difference was found in DNA methylation after plant regeneration from embryogenic calli. The significance of a tissue culture model system with no global hypo- or hypermethylation is discussed.