MOLECULAR SEARCH FOR MRNA AND GENOMIC MARKERS OF THE OIL PALM "MANTLED" SOMACLONAL VARIATION

Abstract

In order to improve the fidelity of the clonal process developed for oil palm (Elaeis guineensis Jacq) by the ORSTOM/CIRAD group, we are attempting to identify mRNA and genomic markers for screening of the mantled flowering abnormality found in typically 5-10% of regenerated palms. 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 analysing genomic DNA from somatic embryogenesis-derived material by estimating ratios [5mdC/(5mdC+dC)] using HPLC following enzymic hydrolysis. We are currently identifying mRNAs which show differential accumulation in normal and abnormal tissue cultures. Potential mRNA markers are being identified using the differential display (ddRT-PCR) technique and their expression patterns are being confirmed by Northern blotting. Preliminary results obtained by these complementary approaches are described here and the likely epigenetic nature of somaclonal variation in oil palm is discussed.