Chromosome Pairing in Hybrid Progeny between Triticum aestivum and Elytrigia elongata

In this study, the intergeneric hybrids F(1), F(2), BC(1)F(1), BC(1)F(2), and BC(2)F(1) from Elytrigia elongata and Triticum aestivum crosses were produced to study their chromosome pairing behavior. The average E. elongata chromosome configuration of the two F(1) hybrids agreed with the theoretical chromosome configuration of 21I+7II, indicating that the genomic constitution of this F(1) hybrid was ABDStStE(e)E(b)E(x). Compared with the BC(1)F(1) generation, the BC(2)F(1) generation showed a rapid decrease in the number of E. elongata chromosomes and the BC(1)F(2) generation showed a more extensive distribution of E. elongata chromosomes. In addition, pairing between wheat and E. elongata chromosomes was detected in each of the wheat-E. elongata hybrid progenies, albeit rarely. Our results demonstrated that genomic in situ hybridization (GISH) using an E. elongata genomic DNA probe offers a reliable approach for characterizing chromosome pairing in wheat and E. elongata hybrid progenies.