Abstract
The wabisuke camellia ‘Tarokaja’ is a very old cultivar of unknown origin. Based on morphological properties, it is thought to be an interspecific hybrid between Camellia japonica and an unidentified species from continental China. We analyzed chloroplast DNA from members of the genus Camellia to trace the maternal origin of ‘Tarokaja’. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the atpI-atpH spacer region using 57 progeny derived from 17 interspecific crosses confirmed that chloroplast DNA is inherited maternally in the genus Camellia. Based on PCR-RFLP and sequence analyses of the atpI-atpH region and referring to knowledge about morphological properties, we concluded that the maternal origin of ‘Tarokaja’ is a Chinese native species C. pitardii var. pitardii. Wabisuke camellia cultivars are classified into two groups. One group of wabisuke camellia cultivars is thought to be derived from crosses between ‘Tarokaja’ and C. japonica. Since most of them had a ‘Tarokaja’-type single-base in the atpI-atpH region, it was confirmed that these wabisuke cultivars are descended from ‘Tarokaja’. It is likely that ‘Hime-wabisuke’, ‘Kocho-wabisuke’, and ‘Sukiya’, which had a C. japonica-type single-base, are progeny descended from ‘Tarokaja’ with C. japonica as the maternal ancestor. Another group of wabisuke camellia cultivars is thought to be derived from C. japonica by mutation, and all but one of these had a C. japonica-type single-base. The exception, ‘Kibi’, had a ‘Tarokaja’-type single-base, so that ‘Kibi’ is inferred to be descended from ‘Tarokaja’.
