Grain yield, anthesis-silking interval, and phenotypic plasticity in response to changing environments: Evaluation in temperate maize hybrids

Lack of water and low nutrition affecting crop during the critical period of maize are the main determinants in grain yield variability. Grain yield and anthesis-silking interval (ASI) are two of the main traits used in maize breeding programs. Under drought conditions, selection for a reduced ASI has resulted in greater and more stable grain yield, however, these traits are largely influenced by the environment, showing a high GxE. Thus, the phenotypic plasticity of these traits deserve evaluation. Phenotypic plasticity is the ability to change the phenotype according to environmental conditions. Therefore, plasticity can be high (unstable trait) or low (stable trait). In the current research, 7 temperate maize hybrids were assessed in 13 environments, including water and nitrogen stress environments, in the Mediterranean climate area of Chile with the objective to evaluate grain yield, anthesis-silking interval, and phenotypic plasticities. Within the group of evaluated traits, ASI and grain yield had the highest phenotypic plasticity for the set of temperate maize hybrids studied. These results confirm the higher HxE interaction for these traits and the necessity to evaluate “ASI plasticity” and its relationship with yield stability. ASI plasticity was positively associated with yield plasticity (r = 0.93; p = 0.002). Only in water stress environment, a greater ASI plasticity was significantly associated with a greater ASI (r = 0.98; p = 0.00008) and lesser grain yield (r = −0.76; p = 0.047). The greater yield plasticity was associated with a lesser grain yield (r = −0.88; p = 0.009) and a greater ASI (r = 0.93; p = 0.003). There were no associations between these traits under potential and N-stress conditions. According to this research, it is corroborated the necessity to assess “ASI plasticity” as a compliment of ASI for breeding proposes under water stress conditions in temperate hybrid maize. •Grain yield and Silking-Anthesis Interval have highest phenotypic plasticities in temperate hybrid maize.•Associations between traits are found in the water deficit environment only.•Grain yield plasticity is related to lower grain yields and higher silking-anthesis intervals.•Silking-anthesis interval plasticity is correlated with higher silking-anthesis intervals and lower grain yields.•Positive association between grain yield plasticity and silking-anthesis interval.