REPETITIVE DNA-SEQUENCES FROM POLYPLOID ELYMUS-TRACHYCAULUS AND THE DIPLOID PROGENITOR SPECIES - DETECTION AND GENOMIC AFFINITY OF ELYMUS CHROMATIN ADDED TO WHEAT

A set of four repetitive DNA clones, pEt1, pEt2, pCb1, and pCb3, were isolated from SH-genome polyploid Elymus trachycaulus and H-genome diploid Critesion bogdanii. The clone Et1 represents a tandemly arranged telomeric sequence. Et2 represents tandem repeats interspersed along the entire length of individual chromosomes. The Cb1 sequence was more evenly dispersed. The Et1 clone shared homology with a 350 base pair family of rye sequences. The Cb3 sequence was evenly distributed in S- and H-genome species. All the repetitive DNA sequences were excellent markers for the specific detection and genomic affinity of Elymus chromatin added to wheat. All clones showed intragenomic variation in copy number and chromosomal location. Based on the analysis of this variation, we conclude that E. trachycaulus most probably originated from putative diploid H- and S-genome species resembling Critesion californicum and Pseudoroegneria spicata, respectively.