Genotype by Environment Interaction in Zoysiagrass.

Zoysiagrass is becoming an increasingly important turfgrass throughout the southern United States. Recently there has been an increase in the availability of commercial cultivars and the breeding of zoysiagrass for turf is occuring at several locations. As part of a collaborative warm season turfgrass breeding effort between the University of Florida, Texas A and M University, Oklahoma State University, the University of Georgia and North Carolina State University 160 experimental zoysiagrass genotypes and five check cultivars ('Palisades', 'Empire', 'El Toro', 'Zorro', and 'Zeon') were planted at seven locations in 2011. Entries were planted at each location in randomized complete block designs with two replications using a single plug per plot. Genotypes were evaluated at each location for percent plot establishment, color and turf quality. Genotype by environment effects were analyzed using ASReml software and biplots were contructed using R-package statistical software. Genotype by environment interactions were significant for all traits and the biplot analysis indicated the presence of mega-environments. Both analysis identified genotypes best adapted to specific environments and which genotypes are well adapted to multiple environments.