Generating novel plant genetic variation via genome editing to escape the breeding lottery

Abstract

Plant breeding relies on the presence of genetic variation, which is generated by a random process of mutagenesis that acts on existing gene pools. This variation is then recombined into new forms at frequencies impacted by the local euchromatin and heterochromatin environment. The result is a genetic lottery where plant breeders face increasingly low odds of generating a “winning” plant genotype. Genome editing tools enable targeted manipulation of the genome, providing a means to increase genetic variation and enhancing the chances for plant breeding success. Editing can be applied in a targeted way, where known genetic variation that improves performance can be directly brought into lines of interest through either deletion or insertion. This empowers approaches that are traditionally difficult such as novel domestication and introgression of wild accessions into a germplasm pool. Furthermore, broader editing-mediated approaches such as recombination enhancement and targeted random mutagenesis bring novel ways of variation creation to the plant breeding toolbox. Continued development and application of plant genome editing tools will be needed to aid in meeting critical global crop improvement needs.