Genomic assessment of white clover and perennial ryegrass genetic resources
Keywords:core collection, Lolium, genetic diversity, genotyping-by-sequencing Trifolium
Forage resources conserved in genebanks, such as the Margot Forde Germplasm Centre (MFGC; Palmerston
North), are reservoirs of genetic diversity important for the development of cultivars adapted to abiotic stresses and environmental constraints. Genomic tools, including genotyping-by-sequencing (GBS), can support identification of manageable subsets (core collections) that are genetically representative of these large germplasm collections, for phenotypic characterisation. We used GBS to generate SNP (single nucleotide polymorphism) profiles for 172 white clover (WC) and 357 perennial ryegrass (PRG) MFGC-sourced accessions and estimated genetic relationships amongst accessions. In WC, accessions aligned along an east-west transect from Kazakhstan to Spain, identifying major diversity in Caucasus/Central Asia and Iberian Peninsula. A key feature was the reduced diversity present in New Zealand (NZL) accessions. Similarly, for PRG, most NZL accessions coalesced as one group, distinct from large clusters associated with the Iberian Peninsula, Italy and eastern Mediterranean/Caucasian region. These results emphasise the relatively narrow genetic diversity in NZL WC and PRG, and the broad extent of largely unexploited global diversity. Capturing global genetic variation in
core collections will support pre-breeding programmes to mobilise novel genetic variation into New Zealand-adapted genetic backgrounds, enabling development of cultivars with non-traditional traits including enhanced
climate resilience and environmental performance.
This work is licensed under a Creative Commons Attribution-Non Commercial-NoDerivatives 4.0 International License. Rights granted to the New Zealand Grassland Association through this agreement are non-exclusive. You are free to publish the work(s) elsewhere and no ownership is assumed by the NZGA when storing or curating an electronic version of the work(s). The author(s) will receive no monetary return from the Association for the use of material contained in the manuscript. If I am one of several co-authors, I hereby confirm that I am authorized by my co-authors to grant this Licence as their agent on their behalf. For the avoidance of doubt, this includes the rights to supply the article in electronic and online forms and systems.