1994 Volume 44 Issue 1 Pages 53-57
The genetic mechanism of cool temperature resistance at the booting stage of rice, is largely unknown in spite of the significance in rice cultivation. We have screened 317 M2 lines derived from chemically mutagenized cv. Taichung 65 which is highly resistant to cool temperature. Repeated screening from M3 through M6 generation recovered seven cool temperature sensitive mutants. They showed significantly lower seed fertility than Taichung 65 when treated with cool water (19°C). Although the seed fertility fluctuated to some extent with years, four of the seven mutants showed very low seed fertility and one relatively high but significantly lower seed fertility than Taichung 65 and The remaining two showed intermediate values. Segregation of seed fertility in F2 plants between Taichung 65 and the mutants suggested that many of the mutants were due to single-gene recessive mutations. In four mutants, pollen development was severely damaged by cool water treatment. Also female organ (embryosac) was malformed in some mutants. These seven mutants are potential materials for the investigation of cool resistance in rice.
