Genome recombination in intergeneric hybrids between tetraploid Festuca pratensis and Lolium multiflorum

Abstract

Recombination of homoeologous genomes was studied using in situ hybridization of the total genomic DNA in four F8 populations selected from reciprocal intergeneric hybrids of tetraploid (2n = 4x = 28) Lolium multiflorum with Festuca pratensis. The populations were selected for agronomic performance as forage grasses. They are fertile and productive and have satisfactory levels of stability and uniformity. The proportion of the total genome length occupied by the L. multiflorum chromatin among the 25 plants analyzed ranged from 49.2% to 66.7% and significant differences within and among the populations were found. Apart from the consistently higher proportion of L. multiflorum chromatin, no other patterns of introgression were apparent. This suggests that despite considerable taxonomic distance, the chromosomes of the two genera are genetically equivalent and almost perfect mixing of the genomes is possible.