Daniel Tolhurst: Disentangling non crossover and crossover genotype by environment interaction 

Genotype by environment interaction (GEI) is the phenomenon describing how individuals (e.g. animals, plants) respond differently to different environments. In plant breeding particularly, GEI is routinely categorised as either non-crossover or crossover interaction, which reflect changes in the scale of individual response between environments or changes in rank. Despite the important distinction, however, current methods retrospectively diagnose and test for their presence rather than actively separate them. This talk will explicitly show how non-crossover and crossover GEI can be disentangled, creating two new independent traits. Here, the first trait exclusively captures the response of individuals to non-crossover GEI (changes in scale), while the second trait captures their response to crossover GEI (changes in rank). The new approach will be demonstrated using plant breeding datasets with low and high levels of GEI, reflecting low and high levels of re-rankings between environments.