We are attempting to identify mRNA and genomic markers for screening of the "mantled" flowering abnormality found in typically 5-10 % of regenerated plants. Analyses of genome size and structure are being performed using flow cytometry and RAPD techniques. Studies of genomic methylation, which is thought to play an important role in the induction of somaclonal variation, are under way. We are analyzing genomic DNA from somatic embryogenesis-derived material by estimating ratios using HPLC following enzymic hydrolysis. Potential mRNA markers are being identified using the differential display technique and their expression patterns are being confirmed by Northern blotting.