Acta Scientifica Malaysia (ASM)

Cytoplasmic male sterility (CMS), a maternal-effect inheritance, refers to a plant’s inability to produce fertile pollen, which is caused by disharmony between nuclear and mitochondrial genes. CMS normally results in sterile male reproductive organs in the plant, which can be overcome by restorer of fertility (Rf) genes. This review integrates current information on CMS systems, their genetic mechanisms, origins, importance, and applications in major crops like rice, wheat, maize, sunflower, and onion from comprehensive scientific literature. In spite of its known advantages, CMS presents certain drawbacks and genetic instability, which the review discusses. Some of the most efficacious CMS systems—for example, PET-1 in sunflower and CMS￾WA in rice—have been found to facilitate stable sterility along with efficient fertility restoration. Therefore, such varieties have opened gateways toward genetically pure hybrid seeds that yield more, possess better disease resistance, and have greater stress tolerance. However, challenges still exist. CMS-based crops can be genetically fragile, and the limited diversity of CMS sources threatens long-term breeding achievements. Besides just raising yields, CMS has streamlined breeding programs and improved some of the most important agronomic characteristics. Therefore, the future of breeding is expected to see the development of new CMS sources and their broader practical application to address global food security challenges.