Visualization of U and M genome chromosomes by multicolour genomic in situ hybridization in Aegilops biuncialis and Triticum aestivum-Ae. biuncialis amphiploids

The multicolour genomicin situhybridization (mcGISH) method was improved in order to visualize the Uband Mbgenomes ofAegilops biuncialisVis. (2n=4x=28, UbUbMbMb). Hybridization probes prepared from the diploid U and M genome donors,Ae. umbellulataandAe. comosa, resulted in clear hybridization signals on the U and M chromosomes inAe. biuncialis. The random primed labelling method made it possible to decrease the blocking ratio to 1:30. McGISH allowed the simultaneous discrimination of individualAe. biuncialisgenomes and wheat chromosomes in γ-irradiatedTriticum aestivum-Ae. biuncialisamphiploids (2n=70; AABBDDUbUbMbMb). Dicentric chromosomes, terminal and interstitial translocations and centric fusions were detected in the irradiated generation. The irradiation-induced wheat-Ae. biuncialisintergenomic translocations will facilitate the successful introgression of useful agronomic traits into bread wheat.