Plant & Animal Genomes XIV Conference Plant & Animal Genomes XIV ConferenceJanuary 14-18, 2006
Town & Country Convention Center
San Diego, CA
The plant genome is constituted from three tightly co-operating compartments in nucleus, plastids (cp), and mitochondria (mt). Generally, the plastid genome is considered the most slowly evolving of theses sub-genomes, and cp molecular markers have been used for evolutionary studies on taxonomic levels from genera to families. In contrast, cp microsatellite (SSR) markers have a high level of variability at the mononucleotide level, and thus are highly suitable for a range of applications such as pedigree analysis in plant breeding, reconstruction of phylogeny, and distinction of hybrids of closely allied species. We have developed a set of novel 19 cp SSRs for Lolium perenne, which are partially suitable for 50 other grass species from 9 subfamilies of the Poaceae. These markers have been applied for the investigation of cp haplotypes in European populations of Lolium. The integration of different genomic backgrounds has to be investigated with nuclear molecular and physical markers. Perennial ryegrass is usually an outbreeder with a self-incompatibility system. For the construction of recombinant inbred lines; we have used as starting material highly inbred line material which is self-compatible and which has originally been derived from an inter-generic cross between Lolium perenne and Festuca pratensis. Presently we are constructing a detailed genetic map of 360 individuals of the F2 population based on the inbred parental lines, and we map QTLs contributing to biomass heterosis. The parental lines and the F1 generation are physically characterized via FISH (fluorescence in-situ hybridization) experiments. Hybridizations with a 28S rDNA probe indicate an unusual and complex genome structure of the inbred lines.