NEW RESTORERS FOR WA-CYTOPLASMIC GENIC MALE STERILE (CMS) LINES IN RICE (ORYZA SATIVA L.)

A study was undertaken with 50 cross combination obtained by crossing five cytoplasmic genic male sterile (CMS) lines of wild abortive (WA) source and ten male parents in a line x tester mating design. Based on pollen and spikelet fertility of the hybrids, seven male parents viz., BR 736-20-3-1, IR 31406, IR 50400-641-2-2-2, IR 8866-20-3-1-4-2, MDU 3, MDU 4 and Ponni were identified as effective restorers for all the five male sterile lines viz., PMS 9A, PMS 10A, V 20A, IR 58025A and IR 62829A. The other three pollen parents viz., BR 20370-B-2, IR 20 and IR 49457-33-1-2-2-2 were either partial restorers or partial maintainers of the CMS lines studied. No effective maintainer was identified for any of the CMS lines studied. Differential reaction of same genotype in restoring fertility of different lines of the same CMS source might be due to interaction between nuclear and cytoplasmic genomes. Since significant positive correlation between pollen and spikelet fertility was realized, spikelet fertility could alone be considered to be as criterion for classification of the male parents tested for fertility restoration into restorers and maintainers.