Geographic distribution and origin of the chloroplast T/C-type in Quercus mongolica var. crispula in northeastern Japan: Chloroplast T/C-type in Quercus

In order to investigate the historical expansion of common oaks (Quercus sect. Prinus) in the northeastern part of Japan, the relation between the chloroplast haplotypes (I and II) in Quercus mongolica var. crispula and the chloroplast types (T- and C-type) were examined. Complete linkage between haplotype II and chloroplast C-type was found. The chloroplasts examined in the oak species collected from Sakhalin and Primorski Krai, Russia, and Harbin, China were all T-type. This suggests that the T to C mutation had occurred in haplotype II in Japan. Neither of haplotype I nor haplotype II was found outside Japan, suggesting both occurred in Japan independently from an ancestral haplotype VI. Haplotype I, which has been known only in Mount Hayachine within Honshu, is distributed southward to the Kanto district, where refugia might have occurred during glaciations.