A characterisation and evaluation (C&E) dataset for a wild/semi-natural perennial ryegrass representative germplasm collection, based on multi-site field-evaluation across an altitudinal gradient in the UK

Our objective is to develop a field-based multi-year phenotype assessment, across a range of UK-relevant environments, of a geographically diverse set of perennial ryegrass wild/semi-natural ex situ accessions. This will inform grassland, environmental and agricultural scientists in developing: 1) experimental approaches to understanding performance and resilience, and 2) a genetic resources strategy for perennial ryegrass, i.e., for a UK-focused core collection. This will also be valuable to the commercial plant breeding and forage seed sector through increasing the germplasm options available for seed product development. The Aberystwyth University Seed Biobank contains c. 3.3k accessions of perennial ryegrass seed in storage, of which c. 50% are wild, semi-natural or traditional cultivars/landraces (SAMPSTAT 1nn). Of the wild/semi-natural perennial ryegrass accessions, 334 have seed quantities >40 g in medium-term storage. This quantity will allow for both field evaluations and for future seed distribution/multiplication. Following germination tests and categorisation for collection site geographical diversity, 200 wild/semi-natural accessions will be sown at 5 sites across an altitudinal gradient (c. 70m-340m above sea level) in non-replicated 1 m2 plots. The field trials will be continued for 3 years using a low N plot management (50kg N/ha/annum) and individual plots will be evaluated for above-ground biomass, ground cover, flowering time, disease incidence, rainfall infiltration, chemical composition and invasion by other species. Ten modern varieties of perennial ryegrass will be grown alongside the wild/semi-natural accessions at each of the field sites for comparison. At the end of the programme, the field-generated phenotype data on individual accessions will be compiled and submitted to the plant germplasm information resources EURISCO and Genesys PGR, as formal characterisation and evaluation datasets to accompany the existing accession entries.