CANDIDATE GENES IN Lolium TARGETED BY COMPARATIVE MAPPING WITH Hordeum

¹ Oregon State University Department of Crop & Soil Science Corvallis, OR 97331

² USDA-ARS National Forage Seed Production Research Center 3450 S.W. Campus Way Corvallis, OR 97331

The transition from vegetative to reproductive development is important in many plant species and is of particular importance in forage and turfgrasses. The annual/perennial ryegrass complex provides a unique opportunity to study genes controlling the transition to flowering in cool season forage and turfgrasses. Comparative genetic mapping of an annual x perennial ryegrass cross using barley markers will increase our understanding of the similarities and differences in flowering control of these two systems. An annual/perennial ryegrass three generation pseudo F2 mapping population of 170 individuals has been developed and is being evaluated for vernalization and photoperiod requirements. Initial isozyme marker scoring at the Pgi 2 locus has shown no significant segregation distortion in this population. The seedling root fluorescence trait shows a two gene segregation ratio. Map density is being increased using both EcoRI and PstI AFLP markers. RFLP markers linked to genes influencing vernalization and photoperiod requirements in spring/winter barley crosses will be evaluated to determine the level of synteny that exists between these two systems. Additional RFLP markers will be scored to establish the level of synteny between ryegrass and other Triticeae genomes.