Genetic Divergence among Intraspecific Taxa of Camellia Japonica L

Isozyme variations of 7 enzyme systems among representatives of indigenous Camellia japonica found growing in 12 geographical regions in Asia were examined to measure the genetic divergence among their intraspecific taxa.The mean genetic identity value between any pairs of regions is 0.77, which is low as compared to the conspecific values of other outcrossing species.This condition is attributed to the very divergent allelic variation that ssp.rusticana possesses as compared to vars.hozanensis and japonica, both of which belong to ssp.japonica.On the contrary, only a small difference exists between var.hozanensis and var.japonica, and the genetic data of these two varieties is reflected by the electrophoretical features of the progenitor/derivative pair.Comparisons between electrophoretic phenotypes in C. japonica with those in Camellia species lead us to two possibilities on how the phylogeny of intraspecific taxa of C. japonica might have evolved.1) Subspecies rusticana arose in earlier times than did vars.hozanensis and japonica, if their ancestors had been the same.2) Varieties hozanensis and japonica arose with introgressive hybridization among different sections of the genus Camellia.