Probing phenotypic and genotypic diversity underlying architectural traits in ryegrass

Plant architecture is one of the growth characters that determine the agronomic potential of crop plants. In fodder grasses, a higher degree of branching will lead to improved yield of biomass and seeds, faster ground coverage at sward establishment, higher sward density, better trampling tolerance, better re-growth after damage or cutting, more generative tillers, and improved persistence.
Although recently some genetic factors controlling plant architecture have been elucidated in model plants such as Arabidopsis, tomato, and pea, the knowledge of the genetic and environmental control of plant architecture is limited in most crop species. We have established a collection of about 600 Lolium perenne genotypes, including turf and forage cultivars and natural accessions originating from across Europe. A selection of these are currently being phenotyped for tillering and re-growth response and the correlation to other agronomic traits such as biomass yield and heading date will be established. These growth traits show extensive variation both between and within cultivars and natural accessions. In parallel, we will perform large-scale allele mining to examine the allelic diversity of candidate genes involved in branching for use in association genetics.