2003 Volume 5 Issue 4 Pages 149-154
The clonal, garden-variety camellia `Robiraki' has been considered to be an interspecific hybrid derived from natural crossing between Camellia japonica var. decumbens and tea (C. sinensis), based on its morphological characteristics, the location of and the meteorological conditions under which it was discovered. However, DNA investigations which are essential for the confirmation of the hybridity of `Robiraki' had not been conducted. In this study, we examined the hybridity of `Robiraki' using Random Amplified Polymorphic DNAs (RAPDs) and a Simple Sequence Repeat (SSR) marker. All the bands detected in the RAPD analysis of `Robiraki' were detected in C. japonica and / or tea. In the analysis with the SSR marker (TMSLA-45), which is non-polymorphic in tea, the size of the PCR products generated from C. japonica was different from those of the products derived from tea; `Robiraki' harbored the SSR markers of both C. japonica and tea. These results indicated that `Robiraki' was derived from crossing between C. japonica and tea. Using maternally inherited RAPD and emphasized-RAPD (e-RAPD), we confirmed that the cytoplasm of `Robiraki' was different from that of original Japanese tea clones. `Robiraki' was an interspecific hybrid between C. japonica as seed parent and tea as pollen parent. When we crossed tea with `Robiraki', an individual with tea-like traits and some minor C. japonica-like traits, such as light pink flowers was produced. This individual inherited some RAPDs and one SSR marker from C. japonica via `Robiraki'. It is considered that `Robiraki' and the hybrid may play an important role in genetic bridging for the breeding of C. japonica to tea breeding.
