Italian Ryegrass (Lolium multiflorum) is a fodder grass for a one to two years cropping system. In breeding programmes clones are tested for general combining ability in topcross tests. Productivity is measured on clones, which are heterozygous so that many weak alleles are covered. Self progenies of L. multiflorum can be obtained by temperature treatment of flowering plants. Genetic variability was estimated on inbred lines, topcross progenies from pollinated inbred lines, progenies from the crossings of inbred lines and synthetics. With the isoenzymes Acp and Pgi inbred lines and crossings were checked for foreign alleles and ‘unclean’ material was eliminated. Inbreeding depression was recorded from inbred clones that were compared with a standard variety and the comparison of five varieties with ten inbred lines. Association studies between AFLP markers and phenotypic traits were conducted with inbred lines of L. multiflorum and L. perenne. Segregating markers were used for mapping of L. perenne. Primer pairs were developed from a Lolium cDNA-library for sequences containing microsatellites. They were also tested in bulks of oat and barley. SNPs and microsatellites from barley-ESTs and genomic microsatellites from wheat were tested in Lolium. For the identification of gene pools of inbred lines, varieties and gene bank accessions AFLPs were used.