Genotype × environment interaction patterns of dry matter yield in meadow brome, orchardgrass, tall fescue, and timothy evaluated at harsh winter sites

Authors: Robins, Joseph; BILIGETU, BILL - Aafc Lethrdge Research Center; CLAESSENS, ANNIE - Aafc Lethrdge Research Center; KHANAL, NITYANANDA - Aafc Lethrdge Research Center; ASSELIN, SEAN - Agriculture And Agri-Food Canada; SCHELLENGERG, MIKE - Aafc Lethrdge Research Center

Submitted to: Grassland Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2024
Publication Date: 7/8/2024
Citation: Robins, J.G., Biligetu, B., Claessens, A., Khanal, N., Asselin, S.R., Schellengerg, M. 2024. Genotype × environment interaction patterns of dry matter yield in meadow brome, orchardgrass, tall fescue, and timothy evaluated at harsh winter sites. Grassland Research. http://dx.doi.org/10.1002/glr2.12088.
DOI: https://doi.org/10.1002/glr2.12088

Interpretive Summary: Because of differential performance of forage grass varieties in different locations, producers have a difficult time choosing the variety(ies) best adapted to their production area. To better understand the genotype by environment interaction among North American forage grass varieties and production areas, we evaluated the forage yield of various North American meadow brome, orchardgrass, tall fescue, and timothy varieties at seven locations in the U.S. and Canada. For each of the species, we found differences among the varieties for forage yield across the locations. The differential performance of varieties across locations was substantial. We found little evidence of broad adaptation of varieties across locations.

Technical Abstract: Background: Genotype × environment interaction (GEI) slows genetic gains and complicates selection decisions in plant breeding programs. Forage breeding program seed sales often encompass large geographic regions to which the cultivars may not be adapted. An understanding of the extent of GEI in perennial, cool-season forage grasses will facilitate improved selection decisions and end-use in areas with harsh winters. Methods: We evaluated the forage yield of nine meadow brome (Bromus biebersteinii Roemer & J. A. Schultes), nine orchardgrass (Dactylis glomerata L.), seven tall fescue (Lolium arundinaceum [Schreb.] Darbysh.), and ten timothy (Phleum pratense L.) cultivars or breeding populations at seven high latitude and/or elevation locations in Canada and the USA from 2019 to 2021. Results: For each of the species, we found significant differences among the germplasms for forage yield across environments and found significant levels of GEI. Using site regression analysis and GGE biplot visualizations, we then characterized the extent of the interactions in each species. Except for tall fescue, there was little evidence for the broad adaptation of germplasms across locations. Conclusions: This research adds further evidence to the limitations of perennial, forage breeding programs to develop widely adapted cultivars and the need to maintain regional breeding efforts.