Abstract: cDNA representational difference analysis (cDNA-RDA) was applied to clone genes specifically expressed in cold and longday induced sugar beet (Beta vulgaris L.). One cDNA fragment was obtained after 3 rounds of subtractive hybridization and amplified by 3′-RACE and 5′-RACE. A sequence of 609 bp cDNA named Ty7Br600 and 855 bp DNA named Ty7Br900 were obtained respectively by RT-PCR and PCR after cloning and sequencing. Blasting in GenBank shows no homology with them, suggesting that it may be a novel gene of sugar beet. Results of Northern blotting and Southern blotting showed that the cDNA clone was only expressed in the cold induced sugar beet and low copy in sugar beet genome.

Key words: Sugar beet, Cold and longday induced, Representational difference analysis (cDNA-RDA), Gene cloning, Sequence analysis