RETROTRANSPOSON BASED MARKERS AND THEIR APPLICATIONS IN BARLEY (Hordeum vulgare L.cvs.) TISSUE CULTURE

Barley has economical value and it is an important model plant. Transposons cover more than 80% of barley genome. More than 40 retrotransposons were characterized in barley genome. This type of transposons replicate via RNA and move in the genome. As a result of these movements, mutations and genome enlargements are occurred. During the recent years, active transcripts and protein products of some retrotransposons have been determined. Somaclonal variations are spontaneously occurred variations in tissue culture conditions. These variations could be produced by genetic and/or epigenetic mechanisms and result in problems in gen transfer applications. We investigated the retrotransposon movements in barley tissue culture and regenerated plantlets using inter retrotransposon amplified polymorphism (IRAP), inter primer binding side (iPBS) and analytical techniques (DNA and RNA levels) and determined the relationship between retrotransposon movements, changes in copy number and differention in culture conditions. For these purposes BARE1, NIKITA, BAGY2 and SUKKULA retrotransposons were analyzed. Our research results show that tissue culture conditions and time increase the transposon based variation and copy numbers of retrotransposons and thus, cause genome enlargements. This research will be contribute the understanding of basic mechanisms related to plant development and differentiation in cultured material and also restriction of variations in applications. Keywords: Barley, Tissue Culture, Retrotransposon markers, Somaclonal variatio