Research on a Method for Purification and Multiplication of PTGMS Lines

Objective] The aims was to explore PTGMS line purification and multipli- cation technology. Method] Three commercial PTGMS lines, Annong 810S, P88S and C815S, were used in this study. In the first year, two sterile line populations with same genetic background were multiplied by dividing seedling; meanwhile, se- lection and multiplication of the core individuals were conducted; within the year, the core seeds harvested were multiplied under the isolated condition in Hainan, and at the same time, superior individuals were selected and used as the seeds for two populations with same genetic background in the next year. In the second year, seeds harvested in Hainan were planted in Changsha, while the core individuals were selected and multiplied; the core seeds harvested were continued to multiply in Hainan. The above procedures were repeated in the following years. Result] The test results showed that in two years the proportion of core individuals in the popu- lation of Annong 810S, P88S and C815S increased from 40.3%, 0.7% and 0.3% in the first year to 71.67%, 66.00% and 68.67% in the second year respectively. Conclusion] This suggested that this method of purification and multiplication of the PTGMS lines for consecutive years can effectively control the drift of the critical sterility inducing temperature, and at the same time, core seeds with high purity and controlled inducing temperature can be harvested.