The cytoplasmic male sterility (CMS) system is widely used to develop rice hybrids. Although effective, this system is quite cumbersome to practice. Certain genic male sterile lines that revert to fertility under specific temperature are called thermosensitive genic male sterile (TGMS) lines. Deployment of the TGMS system to develop two-line hybrids has several advantages over the conventional CMS system, as it requires neither maintainers for seed multiplication nor restorers for producing hybrids. In addition, two-line hybrids may not suffer from possible negative effects of the sterility-inducing cytoplasm.