Suitability of Maintainers and Restorers for CMS Lines in Rice

Hybrid rice technology has been successfully developed and is one of the potent options for increasing rice production. The use of cytoplasmic genetic male sterility system in developing hybrids in crops is possible only when effective restorers are identified. Pollen (or) spikelet fertility or both have been used as an index to fix the restoration ability of the lines. In the present investigation 19 genotypes were crossed with four stable CMS lines during Rabi 2009- 2010 at Paddy Breeding Station, Coimbatore. Genotypes were categorized as effective restorers (> 80 % spikelet fertility), partial restorers (20-79% spikelet fertility), partial maintainers (10-19 % spikelet fertility) and maintainers (<10 % spikelet fertility). A total of eighteen effective restorers and eight maintainers were identified among 100 genotypes against four CMS lines. The pollen fertility per cent of hybrids varied from 0 to 98.30%. The spikelet fertility of F1s ranged from 0 (IR 80151 A x CB 06 107) to 98.65 (TNAU CMS 2A x CB 06 734). Maximum number of maintainers were observed against IR 80151A. The maximum number of effective restorers were observed against TNAU CMS 2A. The identified restorers and maintainers could be utilized for development of new rice hybrids and CMS lines respectively in future.