Cytoplasmic male sterility is used to develop hybrids in many crop species. The system depends on a maintainer stock to maintain the female parental line and a restorer male line to produce a fertile offspring.

Major seed companies have experimented with a transgenic Avidin gene from Streptomyces bacteria. The avidin protein sequesters the biotin vitamin resulting in male sterility. The addition of biotin via timely sprays can recover the male infertility and the sprayed plants can be used as male stock while the unsprayed can function as females in a crop like maize.

In sorghum a plastic bag can prevent pollen from forming based on high humidity and temperature. These plastic bagged plants can be used as females and paper bagged plants are used to collect viable pollen which is used as the male. The female plants are dwarf colorless and the male can be pigmented so with germination only pigmented plants represent the hybrids.

There are various chemicals that can induce male sterility while maintaining female function and a literature review is recommended for greater information and engagement.