Detection of various U and M chromosomes in wheat-Aegilops biuncialis hybrids and derivatives using fluorescence in situ hybridisation and molecular markers

The aim of the study was to select wheat-Aegilops biuncialis addition lines carrying Aegilops biuncialis chromosomes differing from those which were introgressed into the wheat-Ae. biuncialis addition lines produced earlier in Martonvásár, Hungary. In the course of the experiments new wheat-Ae. biuncialis addition lines carrying chromosomes 2U^b, 6M^b, 6U^b; 5U^b, 3U^b, 7U^b; 5M^b, 6M^b and 7M^b were selected. The 2U^b disomic addition line is relatively stable, as 91% of the progenies contain this chromosome pair. The 6M^b disomic addition line proved to be dwarf and sterile, but it still exists as a monosomic addition line. Progenies analysed from the 6U^b monosomic addition line did not carry the 6U^b chromosome. One plant containing the 5U^b, 3U^b and 7U^b chromosomes and one plant carrying 5M^b, 6M^b and 7M^b chromosomes showed very low fertility. Each of the plants produced a single seed, but seeds of the parent plants are still available. Line No. 49/00 carried a submetacentric Ae. biuncialis chromosome pair and the chromosome number 44 has been constant for several generations. After FISH no hybridisation site was observed on the Ae. biuncialis chromosome pair using the pSc119.2 and Afa family repetitive DNA probes, so it was not possible to identify the Ae. biuncialis chromosome pair. However, the use of wheat SSR markers and the (GAA)_n microsatellite DNA probe allowed it to be characterised more accurately. These new lines facilitate gene transfer from Ae. biuncialis into cultivated wheat and the selection of U and M genome-specific wheat SSR markers.