GENOME RECOMBINATION IN INTERGENERIC HYBRIDS BETWEEN TETRAPLOID FESTUCA-PRATENSIS AND LOLIUM-MULTIFLORUM

Recombination of homoeologous genomes was studied using in situ hybrid ization of the total genomic DNA in four F-8 populations selected from reciprocal intergeneric hybrids of tetraploid (2n = 4x = 28) Lolium m ultiflorum with Festuca pratensis. The populations were selected for a gronomic performance as forage grasses. They are fertile and productiv e and have satisfactory levels of stability and uniformity. The propor tion of the total genome length occupied by the L. multiflorum chromat in among the 25 plants analyzed ranged from 49.2% to 66.7% and signifi cant differences within and among the populations were found. Apart fr om the consistently higher proportion of L. multiflorum chromatin, no other patterns of introgression were apparent. This suggests that desp ite considerable taxonomic distance, the chromosomes of the two genera are genetically equivalent and almost perfect mixing of the genomes i s possible.