Cytomixis in Pollen Mother Cells of Salvia miltiorrhiza

Abstract Cytomixis has been described in many plant species, but not in Salvia miltiorrhiza Bunge, a well-known Chinese herb. The present study reports spontaneous cytomixis during microsporogenesis in S. miltiorrhiza (2n = 16) for the first time. Cytomixis frequently occurred in early prophase I but very rarely in meiosis II. The type of cytomixis that occurred most often was where chromatin migrated from one nucleus into an adjacent cell. Migration from one nucleus into two or more than two cells, or from two or more nuclei into one cel1 was also observed. In addition to cytomixis, other meiotic abnormalities were also found, but the results showed that cytomixis had no significant effect with pollen viability and seed efficiency. The possible causes, cytological consequences and genetic significance of cytomixis were discussed.