Cloning and characterisation of a new rye-specific repeated sequence

In this paper we describe a repetitive DNA sequence unique to the rye genome. The corresponding DNA probe (pAW173) was cloned as a 450-bp fragment and does not hybridize to wheat or barley DNA and is not related to five other repeated DNA families characterised in rye. This new family (designated the R173 family) consists of moderately repeated DNA (~ 15 000 units per genome) and is present on all seven rye chromosomes. The hybridization patterns in Southern blots indicate that it is not organised as blocks of tandem arrays and in situ hybridization shows that it is dispersed throughout the rye chromosomes. The probe has been successfully used as a molecular marker in identifying rye genetic material in a wheat background.Key words: repetitive DNA sequence, rye-specific DNA, molecular marker.