A Hierarchical Screening Strategy for Genome-Edited Events in Polyploid Species: A Case Study on Hexaploid Common...

Genome editing via CRISPR/Cas9 has been widely adopted in cereal crops. In diploid species such as rice and barley, the generation of knockout mutants is relatively straightforward for functional characterization of the genes of interest due to their single-copy nature in the genome. In contrast, common wheat (Triticum aestivum L.) is a hexaploid species comprising three subgenomes (AABBDD); consequently, most genes are present as three homoeoalleles that retained substantial function redundancy during evolution. The generation of a complete set of single, double, and triple mutants is therefore essential for elucidating homoeoallele-specific functions and dissecting their contributions to the developmental and agronomic traits. Moreover, ensuring germplasm purity through the elimination of residual T-DNA is critical for maintaining stable mutation, particularly in single- and double-mutant lines. Here, we describe a hierarchical screening strategy for efficient identification of a comprehensive series of CRISPR/Cas9-induced mutants. This approach integrates high-throughput DNA isolation, selection of T-DNA-free mutants, maintenance of a uniform genetic background via backcrossing, systematic screening of all mutant combinations, and molecular confirmation of genome edits. This screening pipeline has proven effective in hexaploid common wheat and is readily adaptable to other polyploid species that are amenable to crossing. © 2026 Wiley Periodicals LLC. Basic Protocol 1: Wheat cultivation and leaf sample preparation Basic Protocol 2: High-throughput DNA isolation Basic Protocol 3: Genotyping using an optimized, cost-efficient T7E1 assay Alternate Protocol 1: Genotyping using the KASP assay Support Protocol 1: Screening of T-DNA-free triple mutants.