Identification of a new family of tandem repeats in Triticeae genomes

A new family of cereal tandem repeats was isolated, characterised and designated as spelt-1. The family of repeats comprises about 2% of the Aegilops speltoides genome; however, its content differs considerably in the genomes of various Triticeae species. Copy number of the constituent sequence, relative to Ae. speltoides, proved to be 40-60 times reduced in the genomes of tetraploid wheats, 400-fold reduced in the genome of Triticum monococcum, and 1200-2400 times in the genomes of the other 19 Triticeae species studied. Drastic difference in the copy number and homology extent of the spelt-1 family sequences between Ae. speltoides and other diploid species allows the utilisation of these sequences as species-specific telomeric markers for Ae. speltoides, provided stringent hybridisation conditions apply. RFLP (restriction fragment length polymorphisms) analysis of spelt-1 reveals polymorphism between the above species. This study of spelt-1 organisation in different Triticum species provided further substantiation of the polyphyletic origin of the B genome of polyploid wheat. This revised version was published online in August 2006 with corrections to the Cover Date.