Association of hard fescue (Festuca brevipila) stress tolerances with genome mapped markers

• Published in: Crop science 2024-03, Vol.64 (2), p.1002-1014
• Main Authors: Bushman, Bradley, Robbins, Matthew, Qiu, Yinjie, Watkins, Eric, Hollman, Andrew, Mihelich, Nicole, Petrella, Dominic, Breullin‐Sessoms, Florence, Chou, Ming‐Yi, Koch, Paul
• Format: Article
• Language: English
• ISSN: 0011-183X; 1435-0653
• DOI: 10.1002/csc2.21155

Hard fescue is an allo‐hexaploid, caespitose, cool‐season grass that is part of the fine‐leaved ovina complex of the Lolium–Festuca clade in Poaceae. It is predominantly used as a low‐maintenance turfgrass and soil stabilization grass in situations with reduced inputs of nitrogen and water. While often recommended for use under tree canopies, prolonged foliar shade can thin turf stands and reduce their functionality; furthermore, gray snow mold caused by Typhula incarnata can further affect hard fescue turfgrass functionality. In this study, we gathered a diverse population of hard fescue collections and varieties, which fit into four genetic structures. Because no genomic reference sequences exist for this species, a contig‐level pseudohaploid genomic reference was assembled from a plant of the hard fescue variety Beacon. With 98% benchmarking universal single‐copy orthologs (BUSCO) coverage from 241 contigs, this reference assembly was used to conduct genome‐wide association analysis. Thirty‐eight single‐nucleotide polymorphism (SNP) markers were associated with foliar shade response phenotypes, including SNPs near molybdate transporter and cytochrome P450 genes. Three SNP markers were associated with gray snow mold responses, with one located near a Protein Kinase G11 gene and corresponding to a 20% improvement in gray snow mold resistance. Core Ideas A primary contig‐level genome of Beacon hard fescue was assembled. A GWAS for shade tolerance resulted in 38 significant loci, with some loci shared among traits. A GWAS for gray snow mold resistance found three loci, two of which were near candidate genes