Phenotypic plasticity of winter wheat heading date and grain yield across the U.S. Great Plains

Authors: GROGAN, SARAH - Colorad0 State University; ANDERSON, JOSHUA - Nobel Foundation; BAENZIGER, P - University Of Nebraska; FRELS, KATHERINE - University Of Nebraska; GUTTIERI, MARY - University Of Nebraska; HALEY, SCOTT - Colorad0 State University; KIM, KI-SEUNG - Nobel Foundation; LIU, SHUYU - Texas A&M University; McMaster, Gregory; NEWELL, MARK - Monsanto Corporation; PRASAD, PV - Kansas State University; REID, SCOTT - Colorad0 State University; SHROYER, KYLE - Kansas State University; ZHANG, GUORONG - Kansas State University; AKHUNOV, EDUARD - Kansas State University; BYRNE, PATRICK - Colorad0 State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2016
Publication Date: 5/27/2016
Citation: Grogan, S.M., Anderson, J., Baenziger, P.S., Frels, K., Guttieri, M.J., Haley, S.D., Kim, K., Liu, S., Mcmaster, G.S., Newell, M., Prasad, P.V., Reid, S.D., Shroyer, K.J., Zhang, G., Akhunov, E., Byrne, P. 2016. Phenotypic plasticity of winter wheat heading date and grain yield across the U.S. Great Plains. Crop Science. 56:2223-2236. doi:10.2135/cropsci2015.06.0357.

Interpretive Summary: Phenotypic plasticity describes the range of phenotypes produced by a single genotype under varying environmental conditions. We evaluated the extent of phenotypic variation and plasticity in thermal time to heading and grain yield in 299 hard winter wheat (Triticum aestivum L.) genotypes representative of the U.S. Great Plains, including both current cultivars and breeding lines and pre-Green Revolution germplasm. Eleven environments in the Great Plains were evaluated during 2012 and 2013. The number of days from 1 Jan to heading across environments ranged from 109 to 150, and the cumulative growing degree-days (GDD) from 1 Jan to heading from 730 to 1,112 °C·d. Environmental mean grain yield ranged from 1.3 to 5.3 Mg ha-1. There was a strong positive correlation between plasticity of GDD (GDDP) and GDD (r=0.81, P<0.001), especially maximum GDD (r=0.90, P<0.001) across environments, indicating genotypes with a greater degree of plasticity developed later, especially within the earliest environments. Plasticity of GDD was negatively associated with yield (r=-0.58, P<0.001), so was detrimental in the germplasm and environments evaluated. Yield plasticity was positively correlated with both maximum (r=0.80, P <0.001) and minimum (r=0.33, P<0.001) grain yield across environments, indicating greater plasticity was favorable under optimal conditions, without a penalty under low-yielding conditions. More than a century of wheat breeding in this region suggests GDDP has declined and yield plasticity has increased at similar rates. This is encouraging because it indicates the favorable plasticity traits (high yield plasticity, low GDDP) have been selected for indirectly and would further respond to selection.

Technical Abstract: Phenotypic plasticity describes the range of phenotypes produced by a single genotype under varying environmental conditions. We evaluated the extent of phenotypic variation and plasticity in thermal time to heading and grain yield in 299 hard winter wheat (Triticum aestivum L.) genotypes representative of the U.S. Great Plains, including both current cultivars and breeding lines and pre-Green Revolution germplasm. The genotypes were evaluated in 11 environments during 2012 and 2013. The average number of calendar days from 1 Jan to heading across environments ranged from 109 to 150, and the cumulative growing degree-days (GDD) from 1 Jan to heading from 730 to 1,112 °C·d. Environmental mean grain yield ranged from 1.3 to 5.3 Mg ha-1. There was a strong positive correlation between plasticity of GDD (GDDP) and GDD (r=0.81, P<0.001), especially maximum GDD (r=0.90, P<0.001) across environments, indicating genotypes with a greater degree of plasticity developed later, especially within the earliest environments. Plasticity of GDD was negatively associated with yield (r=-0.58, P<0.001), so was detrimental in the germplasm and environments evaluated. Yield plasticity was positively correlated with both maximum (r=0.80, P <0.001) and minimum (r=0.33, P<0.001) grain yield across environments, indicating greater plasticity was favorable under optimal conditions, without a penalty under low-yielding conditions. More than a century of wheat breeding in this region suggests GDDP has declined and yield plasticity has increased at similar rates. This is encouraging because it indicates the favorable plasticity traits (high yield plasticity, low GDDP) have been selected for indirectly, and would further respond to selection.