OsMATL mutation induces haploid seed formation in indica rice

Intraspecific haploid induction in maize (Zea mays) is triggered by a native frameshift mutation in MATRILINEAL (MATL), which encodes a pollen-specific phospholipase. To develop a haploid inducer in rice (Oryza sativa), we generated an allelic series in the putative ZmMATL orthologue, OsMATL, and found that knockout mutations led to a reduced seed set and a 2–6% haploid induction rate. This demonstrates MATL functional conservation and represents a major advance for rice breeding.