S19 - Session O1 - DNA methylation and epigenetic variation in vaccinium plants

Authors: Umanath Sharma *, Abir U Igamberdiev, Samir C Debnath

In-vitro propagation is an advanced vegetative propagation technology employed to produce a large number of high-quality plants in a limited time and space. Year-round production of relatively uniform disease and pest free plants could be obtained using in vitro technologies. With the increasing demand of micropropagated plants, different methods of micropropagation using both semi-solid and liquid media have been put into practice. However, maintenance of genotypic and phenotypic integrity sometimes becomes an issue in the plants regenerated by tissue culture. Due to alterations in the tissue culture micro environment, plant cells pass through additional stress which induces genetic and epigenetic instability in the genome of regenerated plants leads to variations in the clones called somaclonal variation. In commercial micropropagation exclusion of such variants is a challenge. Several methods have been developed to detect variants in micropropagation, which can be achieved using morphological, biochemical or molecular markers. On the other hand, epigenetic variation mostly occurs due to cytosine methylation which involving the transfer of a methyl group onto the C5 position of the cytosine to form 5-methylcytosine resulting in the turning on or off the gene. Whole genome bisulfite sequencing is a recent method utilized to identify the epigenetic variants with their relative position of the coding or non-coding regions in the genome. With the advancements in the gene sequencing techniques and more information on the genome sequence being available, such variations can be utilized in plant improvement programs. In this review, tissue culture induced variation in plants are highlighted. Methods of detection of genetic and epigenetic variation are described and the possible utilization of the tissue culture induced variation in crop improvement programs are discussed particularly focussed in vaccinium plants.