Evaluation of test cross combinations of rice hybrids to identify the potential restorers and maintainers

Hybrid rice technology is one of the good options to enhance the productivity of rice. However, identification of locally adaptable maintainers and restorers is important to develop well adoptive hybrid rice varieties. Therefore, an experiment was conducted with the objective to identify the restorers and potential maintainers to develop (CMS) lines in order to use them as parents for future hybrid rice programme. The experiment was conducted at the Rice Research and Development Institute, Batalagoda, Sri Lanka in Maha 2016/17 and Yala 2017 season.147 crosses were produced by using 29 CMS lines crossing with 58 elite inbred lines in Maha 2016/17. F1 hybrids were field evaluated in test cross nursery in Yala 2017. All F1 hybrids and respective male parents were planted on progeny basis in a test cross nursery. Other agronomical practices were conducted according to the Department of Agriculture (DOA) recommendation. Pollen fertility/sterility of the F1 hybrids was observed via light microscope after staining them with I-KI solution. 56 pollen fertile F1 crosses were identified having >81% pollen fertility and 31 male parents were selected for restoration ability. Four pollen sterile F1 combinations were identified and they showed >98.6% pollen sterility and the pollen parents in these crosses were selected for maintaining ability (RES 256) and advanced to backcross breeding programme to develop new CMS lines.