Gene x gene and genotype x environment interactions in wheat

Accelerating the rate of genetic gain of major crops is required to meet the projected global demand for food. Genomic selection (GS) has made valuable contributions to the genetic progress of different species and is currently a routine procedure in most wheat (Triticum aestivum L.) breeding programs (WBP). Accounting for gene x gene (G x G) and genotype x environment interactions (G x E) in GS can significantly enhance genetic improvement by increasing the rate of genetic gain and adaptation of wheat cultivars. However, a comprehensive and updated knowledge of G x G and G x E methodologies is required to define the appropriate breeding strategy. In this review, we start by briefly describing the current situation and relevance of wheat breeding, then we focus on the central concepts of G x G and G x E and discuss the implications, challenges, and opportunities for the implementation of interactions in GS and wheat breeding. This review is primarily intended to be a reference material for wheat breeders and researchers. Nevertheless, most of the concepts exposed are transferable to any other autogamous or clonal crops, and are therefore useful in a much broader scope. We expect to encourage and facilitate the implementation of GS models accounting for interactions in plant breeding.