Identification of SNps for molecular breeding in Lolium perenne

This work is part of the EU Framework 5 project, GRASP (http://www.grasp-euv.dk/). Breeding programs rely on allelic variation between genotypes. In order to exploit this natural variation, genetic markers such as single nucleotide polymorphisms (SNPs) can be identified to enable accelerated PCR-based selection of suitable individuals for breeding. Many of the important traits which are targets for perennial ryegrass plant breeding are quantitatively inherited with a number of QTL underlying each trait. The most reliable and straightforward approach to clone genes underlying such QTL is by map-based cloning. It is therefore important to have the resources available to enable this, including the generation of large insert DNA libraries. Candidate genes for forage quality, nitrogen stability, flowering time, and sugar metabolism have been isolated using a Lolium perenne Bacterial Artificial Chromosome (BAC) library. Full length sequences including promoter and intron sequence have been obtained and primers designed to specific regions. These regions have then been amplified from 20 different L. perenne genotypes and analysed for allele specific SNPs. These SNPs will be tracked in genetically diverse L. perenne populations undergoing a range of selection pressures in order to assess any shifts in allele frequency. The L. perenne BAC library generated compliments an existing BAC library of the closely related species Festuca pratensis, and will facilitate the production of physical maps, genome sequencing, marker development and map based cloning strategies