Genotype-by-environment interaction patterns in rangeland variety trials of cool-season grasses in the Western United States

Authors: Robins, Joseph; Rigby, Craig; Jensen, Kevin

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2020
Publication Date: 4/28/2020
Citation: Robins, J.G., Rigby, C.W., Jensen, K.B. 2020. Genotype-by-environment interaction patterns in rangeland variety trials of cool-season grasses in the Western United States. Agronomy Journal. 10(5). https://doi.org/10.3390/agronomy10050623.
DOI: https://doi.org/10.3390/agronomy10050623

Interpretive Summary: Disturbed rangelands are suseptible to soil erosion, weed invasion, and increased wildfire cycles among other possibilities. Revegetation with desirable perennial plant materials is the best option for stabilizing these disturbed sites. Individual cultivars and species exhibit adaptation to some potential revegatation sites are poorly adapted to others. This study described adaptedness of perennial cool-season grass species and cultivars to five locations in the Intermountain and High Plains regions of the United States. Land managers now have more evidence to make plant materials decisions for revegetation projects in those regions.

Technical Abstract: Rangeland revegatation is necessary to stabilize disturbed sites and increase forage production, but frequently fails due to a variety of environmental and biotic factors. Plant breeding efforts in perennial cool-season grasses result in the development of potential cultivars that must be evaluated in multi-environment trials to determine their level of adaptation. This study evaluated 49 cultivars for ground cover and dry matter yield over five years at five locations in the Intermountain and high plains regions of the United States. The results were significsnt differences among the included cultivars for both traits across and within environments. Yet, there was also crossover-genotype-environment interaction. Thus, highest performing cultivars were to some extent dependent on the environment. Hycrest II crested wheatgrass and Vavilov II Siberian possessed high ground cover (>80%) and dry matter yield (>800 kg ha-1) across locations except at the Eureka, UT location where they possessed low ground cover. These cultivars, and species, also possessed high productivity and stability for both traits. Thus, breeding efforts in the species resulted in widely adapted cultivars that may lack specific adaptation to some environments.