Abstract

The use of cytoplasmic genetic male sterility system (CMS) in developing hybrids in rice is possible only when effective maintainers and restorers are identified. This could be achieved by either pollen and spikelet fertility test or molecular markers or in combination of both. In the present review, authors have made an effort to assess the earlier studies regarding classification of rice germplasm into restorers/maintainers and provided in nutshell. Abundant works have been done by scholars in the past. In most of the studies, the proportion of restorer was less than partial restorer, maintainer and partial maintainer. We came to know that the fertility restoration was genotype specific. In other way, the genotype which is behaving as restorer for one CMS line may behave as maintainer for other CMS line. The variation in the behaviour of fertility restoration indicated that either the fertility restoring genes were different or that their penetrance and expressivity varied with the genotypes of the parents or modifiers of female background. The identified effective restorers could be used for exploitation of heterosis through hybrids. Whereas effective maintainers could be used for development of new CMS lines through successive backcross breeding thereby converting fertile line into sterile line.