Rice–wheat comparative genomics: Gains and gaps

Rice and wheat provide nearly 40% of human calorie and protein requirements. They share a common ancestor and belong to the Poaceae (grass) family. Characterizing their genetic homology is crucial for developing new cultivars with enhanced traits. Several wheat genes and gene families have been characterized based on their rice orthologs. Rice–wheat orthology can identify genetic regions that regulate similar traits in both crops. Rice–wheat comparative genomics can identify candidate wheat genes in a genomic region identified by association or QTL mapping, deduce their putative functions and biochemical pathways, and develop molecular markers for marker-assisted breeding. A knowledge of gene homology facilitates the transfer between crops of genes or genomic regions associated with desirable traits by genetic engineering, gene editing, or wide crossing.