Genetic Control
Cytoplasmic-genetic male sterility is caused by cytoplasmic genes. It is restored by a fertility restoring (Rf) gene (nuclear gene), which results in the development of normal anthers and pollen. This system has been widely used in hybrid seed production in onion, sorghum, safflower, cron, and sugarbeet (Chahal and Gosal,2002), as it overcoms the problems of GMS and CMS. This system imparts a convenience to breeders to control the sterility expression by manipulating the gene-cytoplasm combinations in any selected genotype, and hence becomes highly desirable.