Mapping and marker assisted selection of genomic regions associated with nitrogen use efficiency and other forage productivity traits in Lolium perenne cultivars

Breeding forage grasses capable of using nitrogen (N) fertiliser inputs more efficiently offers a clean technology route to increased sustainability of livestock production, via lowering recommended fertilizer rates, reducing the agricultural footprint with respect to pollution and reducing the wider consumption of non-renewable resources. To identify and incorporate new genes associated with nitrogen use efficiency (NUE) in perennial ryegrass (Lolium perenne) cultivars, we are making use of a research programme in which genetic mapping and marker assisted selection of traits are practiced simultaneously. A mapping population in the genetic background of the current elite cultivar AberMagic has been developed which segregates for N uptake and N utilisation efficiencies as well as a number of forage quality and productivity traits. By phenotyping this population under highly controlled optimal and limiting regimes of N supply in flowing solution culture, a number of genomic regions mapping to linkage groups 1, 2, 5 and 7 have been identified affecting nitrogen relations.