Analyses of somaclonal variation in endosperm-supported mature embryo culture of rye (Secale cereale L.)

Genetic variations, and especially somaclonal variations, are undesirable in genetic transformation. In this study, random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) markers were used for detection of the variation in calli that were obtained from endosperm-supported mature embryo of rye on Murashige and Skoog (MS) medium containing different auxins (2,4-D, dicamba and picloram) at a range of different concentrations (2, 4, 6, 8, 10 and 12 mg/L). High level of auxins caused a reduction in the genomic template stability (GTS) value. While the highest GTS was observed in the calli maintained on MS medium with 2 mg/L dicamba (98.4%), the calli maintained on MS medium with 12 mg/L picloram were found to show the least GTS (81.7%) when RAPD patterns were analysed. Epigenetic changes were more frequent and variable than genetic changes when compared to RAPD and CRED-RA results. DNA hypermethylation was observed at higher concentrations of 2,4-D and picloram, whereas DNA hypomethylation was observed in dicamba. These results indicate that RAPD and CRED-RA techniques can be used for detection of somaclonal variation in in vitro cultures, which is a fundamental step in plant genetic transformation.